1394 Br J Ophthalmol 2001;85:1394–1395 Br J Ophthalmol: first published as 10.1136/bjo.85.11.1394b on 1 November 2001. Downloaded from
coeYcient was calculated by us after digitalis- 5 Wolfs RC, Klaver CC, Vingerling JR, et al. Distri- ing the data points. It equals 0.51. According bution of central corneal thickness and its to Klemm,4 (page 97) the estimate of association with intraocular pressure: The Rot- MAILBOX terdam Study. Am J Ophthalmol 1997;123:767– regression is extremely unreliable and thus 72. useless at r
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Posterior canal predominance in MICHAEL C BRODSKY Centre, 90 Central Street, London bilateral skew deviation Department of Ophthalmology, University of Arkansas EC1V 8AQ. for Medical Science, Little Rock, AR, USA The Allergan Guest Lecture will be deliv- EDITOR,—We were excited to see the recent ered by Professor Jost Jonas of the University case report of Park et al regarding the 30 year of Erlangen, Germany on the subject of the 1 Park SH, Na DL, Kim M. Disconjugate vertical old man with horizontal locked-in syndrome optic disc. 1 ocular movement in a patient with locked-in and disconjugate gaze. We were intrigued by syndrome. Br J Ophthalmol 2001;85:497–8. Further details: Mrs Janet Flowers, Admin- the description of his eye movements on 2 Zee DS. The organization of the brainstem ocu- istrator, 29 Quarry Hill, Grays, Essex, attempted horizontal gaze, whereas “when the lar motor subnuclei. Ann Neurol 1978;4:384–5. RM17 5BT (tel/fax: 01375 383172; email: 3 Leigh RJ, Zee DS. The neurology of eye movements. patient was asked to look to the right side, the 3rd ed. Oxford: Oxford University Press, 1999: [email protected]; website: right eye moved upward with intorsion, and at 19–89. www.iga.org.uk). the same time, left eye moved downward and 4 Brandt T, Dieterich M. Central vestibular extorsion . . . when the patient was asked to syndromes in roll, pitch, and yaw planes. Neuro- Ophthalmol 1995;15;291–303. look to the left side,...theleft eye moved 5 Brodsky MC, Donahue SP. Primary oblique 41st St Andrew’s Day Festival upward with intorsion whereas the right eye muscle overaction: the brain throws a wild pitch. Symposium on Therapeutics moved downward with extorsion.” Magnetic Arch Ophthalmol (in press). resonance imaging revealed a large ventral The 41st St Andrew’s Day Festival Sympo- pontine infarct. The authors postulated that sium on Therapeutics will be held on 6–7 the lesion caused a disturbance in the neural December 2001 at the Royal College of integration of prenuclear inputs to the intersti- Physicians of Edinburgh. Further details: tial nucleus of Cajal. NOTICES Ms Eileen Strawn, Symposium Co-ordinator We believe we can refine further their mech- (tel: 0131 225 7324; fax: 0131 220 4393; anism for this observed disconjugate gaze based email: [email protected];website:www.rcpe. on the anatomy of the vestibular ocular reflect ac.uk). pathways, as it is probably a type of bilateral skew deviation. Each semicircular canal pro- Onchocerciasis vides excitatory innervation to an extraocular 4th International Conference on the muscle and its contralateral yoke, and inhibi- The latest issue of Community Eye Health (No Adjuvant Therapy of Malignant tory innervation to the corresponding antago- 38) discusses onchocerciasis and the impact of 2 Melanoma nist extraocular muscles. The otolithic path- interventions, with an editorial by Bjorn Thyl- ways are less well understood but are believed efors, former director of the Programme for The 4th International Conference on the to follow the same pathways as the semicircular the Prevention of Blindness and Deafness, adjuvant therapy of malignant melanoma will 3 canal pathways. Each anterior semicircular WHO. For further information please contact be held at The Royal College of Physicians, canal provides excitatory innervation to the Community Eye Health, International Centre London on 15–16 March 2002. Further ipsilateral superior rectus and the contralateral for Eye Health, Institute of Ophthalmology, details: Conference Secretariat, CCI Ltd, 2 inferior oblique muscle, while inhibiting the 11–43 Bath Street, London EC1V 9EL. Palmerston Court, Palmerston Way, London yoke ipsilateral inferior rectus and contralateral (Tel: (+44) (0) 20-7608 6909/6910/6923; SW8 4AJ, UK (tel: + 44 (0) 20 7720 0600; superior oblique muscle. Unilateral injury to fax: (+44) (0) 7250 3207; email: fax: + 44 (0) 20 7720 7177; email: these vestibular-ocular pathways produces [email protected]) Annual subscription [email protected]: website: classic skew deviation with hypertropia of one £25. Free to workers in developing countries. www.confcomm.co.uk/Melanoma). eye in all fields of gaze, whereas bilateral injury produces alternating hypertropia in side gaze. Bilateral damage to anterior canal pathways International Centre for Eye Health EUPO 2002 Course Retina causes a posterior canal predominance with bilateral tonic downgaze.4 The International Centre for Eye Health has A course on retina will be held on 15–17 Theoretically, bilateral damage to the published a new edition of the Standard List of March 2002 at Erlangen, Germany, where otolithic-ocular pathways corresponding to Medicines, Equipment, Instruments and Optical European professors will teach European resi- http://bjo.bmj.com/ those of the anterior semicircular canal should Supplies (2001) for eye care services in dents. Further details: Priv Doz Dr Ulrich developing countries. It is compiled by the produce the motility disturbance described in Schonherr, Friedrich-Alexander-University of Task Force of the International Agengy for the the patient reported by Park et al. The disinhi- Erlangen-Nuemberg, Department of Oph- Prevention of Blindness. Further details: Sue bition resulting from such damage would pro- thalmology, Schwabachanlage 6 (Kopfklini- Stevens, International Centre for Eye Health, duce posterior canal predominance, and kum), D-91054 Erlangen, Germany (tel: increase tonus to all four depressors (both 11–43 Bath Street, London EC1V 9EL, UK (Tel: (+44) (0) 20-7608 6910; email: +49 9131-853-4379; fax: +49 9131-853-4332; inferior recti and both superior obliques). email: [email protected] Since the vertical action of the superior [email protected]). erlangen.de). oblique is more prominent in adduction, the on September 28, 2021 by guest. Protected copyright. abducting eye should have a relative hyper- 4th Vitreoretinal Symposium tropia on side gaze (alternating skew on lateral XXIXth International Congress of gaze). Likewise, because the torsional action Frankfurt-Marburg 2001 Opshthalmology of the superior oblique is more prominent in The 4th Vitreoretinal Symposium Frankfurt- abduction, dynamic intorsional movements of Marburg 2001 will take place on 2–3 Novem- The XXIXth International Congress of Oph- the hypertropic eye would be seen on ber 2001 at the Department of Ophthalmol- thalmology will be held on 21–25 April 2002 attempted abduction. ogy, University of Frankfurt/Main, Germany. in Sydney, Australia. Further details: Con- In this scenario, fundus examination should Further details: Prof Dr Frank Koch, Depart- gress Secretariat, C/- ICMS Australia Pty Ltd, demonstrate bilateral intorsion in primary ment of Ophthalmology, University of GPO Box 2609, Sydney, NSW 2001, Australia position, and detailed motility measurements Frankfurt/Main, Theodor-Stern-Kai 7, (tel: +61 2 9241 1478; fax: +61 2 9251 3552; would show an A-pattern. However, these D-60590, Frankfurt/Main, Germany (tel: email: [email protected]; website: findings would have been diYcult to detect in +49 69/6301-5649; fax: +49 69/6301-5621; www.ophthalmology.aust.com). this patient who could not elevate the eyes email [email protected]). above the midline. We believe that bilateral injury to the same pathways may be responsi- International Society for Behçet’s ble for A-pattern strabismus and bilateral 22nd Annual Meeting of the Glaucoma Disease superior oblique overaction seen in some Society (UK & Eire) patients with posterior fossa disease.5 The 10th International Congress on Behçet’s SEAN P DONAHUE The 22nd Annual Meeting of the Glaucoma Disease will be held in Berlin 27–29 June Vanderbilt University School of Medicine, Society (UK & Eire) will take place on 22 2002. Further details: Professor Ch Zouboulis Nashville TN 37232–8808, USA November 2001 at the Central Conference (email: [email protected]).
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such as super oxide dismutase.45This could be LETTERS a plausible explanation as to why such an extraordinarily high level of copper was bound safely in this patient’s liver. Dense Kayser-Fleischer ring in Untreated Wilson’s disease has progressive, asymptomatic Wilson’s disease irreversible consequences, and ultimately causes death.4 The identification of a Kayser- (hepatolenticular degeneration) Fleischer ring remains the most important The Kayser-Fleischer ring is the single most clinical sign for the diagnosis of Wilson’s dis- important diagnostic sign in Wilson’s disease; ease. it is found in 95% of patients. Virtually all Charlotte Anne Sullivan patients with Kayser-Fleischer rings have 1 Department of Ophthalmology, Birmingham and neurological manifestations. Pseudo rings Figure 1 The right eye showing a heavily 1 Midlands Eye Hospital, City Hospital, Western have been described in other conditions. The pigmented red brown Kayser-Fleischer ring. Road, Birmingham B18 7QU, UK density of a Kayser-Fleischer ring correlates with the severity of Wilson’s disease.2 We A Chopdar describe a rare case of a dense Kayser- The patient remains well with no hepatic or Department of Ophthalmology, East Surrey Fleischer ring in an asymptomatic patient neurological manifestations. Hospital, Surrey, UK with an extremely high liver copper content. Comment G A Shun-Shin The recent significant genetic advances, and the clinical implications are discussed. This patient had an extremely elevated liver Department of Ophthalmology, Wolverhampton copper level, 60 times the normal level. She Eye Infirmary, Wolverhampton, West Midlands, UK had to our knowledge the highest ever Case report Correspondence to: Miss C A Sullivan, Birmingham published liver copper content level over twice At the age of 14 this 23 year old white woman and Midlands Eye Hospital, City Hospital, Western the highest level recorded in other Road, Birmingham B18 7QU, UK had an evisceration of her left eye for painful 4 rubeotic glaucoma following chronic retinal publications. She had a very dense Kayser- Accepted for publication 6 June 2001 Fleischer ring, but no neurological or hepatic detachment, resulting from ANA positive References iridocyclitis. Her optician referred her because abnormalities. Despite the severity of her con- over the past few years, her left prosthetic eye dition she remained neurologically asympto- 1 Finelli PF, Kayser-Fleischer ring: had repeatedly needed an increasingly dense matic with normal liver architecture. hepatolenticular degeneration (Wilson’s disease). Neurology 1995;45:1261–2. brown ring painted onto it, to match her Wilson’s disease is inherited as an auto- somal recessive trait. The defect has been 2 Rodman R, Burnstine M, Esmaeli B, et al. remaining eye. On examination the visual Wilson’s disease: presymptomatic patients acuity in the right eye was 6/6 with a heavily mapped and sequenced to the long arm of chromosome 13 (13q14.3). The Wilson’s gene and Kayser-Fleischer rings. Ophthalmic Genet pigmented red brown Kayser-Fleischer ring 1997;18:79–85. (Fig 1). Her systemic and neurological exami- is responsible for a defective membrane 3 Tankanow RM. Pathophysiology and nations were normal. bound P-type ATPase copper transport mol- treatment of Wilson’s disease. Clin Pharm trans Baseline biochemistry, liver function, hae- ecule, ATP7B. This is located in the golgi 1991;10:839–49. matology, and cerebral magnetic resonance network; the ATPase delivers copper to copper 4 Brewer GJ, Yuzbasiyan-Gurkan V, Wilson’s disease. Medicine 1992;71:139–64. image (MRI) were normal. She was ANA binding ceruloplasmin. During elevated cop- per levels vesicles containing the ATPase and 5 Camakaris J, Voskoboinik I, Mercer JF. positive 1 in 20, serum copper 11.6 µmol/l Molecular mechanisms of copper homeostasis. (normal 11–22), and ceruloplasmin 0.15 g/l copper are released by exocytosis into bile. In patients with a defective gene there is an Biochem Biophys Res Commun (normal 0.15–0.45). Twenty four hour urinary 1999;261:225–32. abnormal accumulation and, in comparison, Thomas GR copper 9.2 µmol/24 h (normal 0.9 µmol/24 h). 5 6 , Forbes JR, Roberts EA, et al. The Haematoxylin and eosin stained liver biopsy low excretion of stored liver copper. These Wilson disease gene: spectrum of mutations showed normal architecture. Orcein and findings contrast with previous theories that and their consequences. Nat Genet rhodanine stains showed patchy excessive Wilson’s disease was caused by a defect of 1995;9:210–17. copper binding protein, and copper within the apo-ceruloplasmin post-translational modifi- cation, and abnormal binding to hepatocytes. The quantified copper content of 4 Rapidly developing intimal the sample was hugely elevated at 3000 µg/g ceruloplasmin. There are a large number of copper binding fibrosis mimicking giant cell (normal 20–50 µg/g). 6 She was treated with trientine dihydrochlo- ATP7B mutations. The clinical heterogeneity arteritis ride.3 The Kayser-Fleischer ring initially be- and overlap of clinical manifestations suggest that locus heterogeneity alone is unlikely to Temporal headache associated with a tender came denser but has faded considerably over superficial temporal artery and decreased the past 5 years; a thin rim still persists (Fig 2). be responsible. It has been hypothesised that there is a subset of pedigrees in which an pulse on palpation are characteristics of giant additional gene is affected other than that for cell arteritis. We report the clinical and biopsy ATP7B.5 Genes encode proteins for detoxifica- findings in a patient in whom these symp- tion of stored copper—for example, metal- toms were caused by a rapid developing If you have a burning desire to respond to lothionein, and neutralisation of free radicals intimal fibrosis. a paper published in the BJO, why not make use of our “rapid response” option? Case report Log on to our website A 51 year old woman presented with a 2 (www.bjophthalmol.com), find the paper month history of a tender and painful left that interests you, and send your response superficial temporal artery (STA). First she noticed a “thickened cord” on the left temple via email by clicking on the “eLetters” which felt pulsatile on palpation. Within 6 option in the box at the top right hand weeks the throbbing pulse disappeared and corner. was followed by tenderness and pain. She also Providing it isn’t libellous or obscene, it reported arthritic pain in the limbs and a will be posted within seven days. You can morning cough overa2yearperiod. She has retrieve it by clicking on “read eLetters” smoked 40 cigarettes per day for 30 years. On on our homepage. examination the left STA felt hardened, knot- The editors will decide as before ted, non-pulsatile, and was slightly tender whether to also publish it in a future overa2cmdistance (Fig 1, cross). There were paper issue. Figure 2 A thin rim still persists 5 years no bruits on auscultation of major arteries. later. The facial and maxillary arteries were soft and
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CRP were normal. She continued having (2) An unreactive paretic pupil that returns diffuse body pain. slowly to normal. Comment (3) Irreversible pupil dilatation with iris atro- phy. GCA is a neurological emergency which, This syndrome has also been reported when when left unrecognised and untreated fre- 2 quently leads to permanent blindness.1 ESR no dilating drops were used. can be normal in 5–30% of patients,23but this In addition to the pupil and iris abnormali- ties, Urrets-Zavalia also described other is an exceptionally rare diagnosis in middle features—iris ectropion, pigment dispersion, aged patients. anterior subcapsular cataract and posterior In summary, our patient presented with a synechiae. No early postoperative pressure clinical picture suspicious of vasculitic occlu- rises were documented, although some had sion of the superficial temporal artery, poly- peripheral anterior synechiae and secondary myalgia, and cough. We present this case as an glaucoma. Gasset also describes the glaucoma illustration that this clinical picture can result as a secondary phenomenon, commenting from rapidly developing intimal fibrosis with- 2 that it is not integral to the syndrome. In the out any evidence of inflammation. series presented by Pouliquen et al, severe A Petzold, G T Plant anterior uveitis, fibrinous exudate, and broad 7 Moorfields Eye Hospital, City Road, London posterior synechiae are described. An early EC1 2PD, UK postoperative intraocular pressure rise is documented in two of the three cases F Scaravilli presented by Tuft and Buckley.8 Department of Neuropathology, Institute of We describe the case of a patient undergo- Neurology, Queen’s Square, London WC1N 3BG, ing deep lamellar keratoplasty for kerato- UK conus who developed a permanently dilated pupil with iris atrophy. In addition she had Correspondence to: Dr Petzold marked anterior uveitis and posterior syn- Figure 1 Accepted for publication 9 July 2001 Thickened, tender, and painful echiae similar to the cases presented by superficial temporal artery in a 51 year old Pouliquen et al.7 Dilating drops were not used. woman. At the site of biopsy the artery was References pulselessness (cross). A knotted appearance 1 Font C, Cid MC, Coll-Vinent B, et al. Clinical Case report is also present distally and rostrally (arrow). features in patients with permanent visual loss due to biopsy-proven giant cell arteritis. Br J A woman with keratoconus underwent a left Rheumatol 1997;36:251–4. deep lamellar keratoplasty at the age of 28 2 Zweegman S, Makkink B, Stehouwer CD. because of unstable contact lens fit and pulsatile on both sides. The C reactive protein Giant-cell arteritis with normal erythrocyte central corneal scarring. A 7.75 mm graft into (CRP) was normal and the erythrocyte sedimentation rate: case report and review of a 7.5 mm diameter recipient DLK was sedimentation rate (ESR) was 4 mm in the the literature. Neth J Med 1993;42:128–31. performed under peribulbar anaesthesia with first hour. Blood pressure was 135/75. 3 Ellis ME, Ralston S. ESR in the diagnosis and sedation. Disposable Baron Hessburg suction It was considered necessary to exclude an management of polymyalgia trephines were used and the deep lamellar rheumatica/giant cell arteritis syndrome. Ann dissection performed after air injection, as inflammatory cause, given the similarity of Rheum Dis 1983;42:168. the presentation to giant cell arteritis. The described by Tuft and Buckley.9 A paracentesis biopsy was taken at the site where the STA was performed and no viscoelastic or air was was pulseless and most prominent (Fig 1). Fixed dilated pupil following injected into the anterior chamber. The proce- The tissue was examined using the serial deep lamellar keratoplasty dure was uncomplicated. block, serial section technique in order to In her medical history of note was atopic minimise the chance of a false negative result. (Urrets-Zavalia syndrome) eczema and hay fever. The histological appearances were those of a A fixed dilated pupil following penetrating The eye became painful during the first severely fibrosed artery devoid of any inflam- keratoplasty is a well recognised if rare postoperative evening. At the first dressing matory changes and consistent with arterio- postoperative complication. We report a case the next morning she was comfortable again sclerosis. The intima was considerably thick- of Urrets-Zavalia syndrome following a deep but the pupil was noted to be semidilated with ened, the internal elastic lamina was lamellar keratoplasty (DLK). To our knowl- an intraocular pressure of 10 mm Hg. The preserved, and the media had some degree of edge this association has not been previously anterior chamber was deep and quiet. fibrosis (Fig 2). The thickened intima, which described. Three weeks postoperatively, despite using had led to tightening of the lumen consisted The mydriasis following penetrating her topical steroids, she developed a marked of collagen and concentrically arranged layers keratoplasty was first described by Castroviejo anterior uveitis with posterior synechiae to of elastic fibres. No thrombotic material could (Castroviejo R, personal communication) but the lens. This responded well to an increase in be observed. it was Urrets-Zavalia who first published his her topical steroids. However, the iris has The patient remained stable overa3year observations on a series of six cases and sug- remained fixed, dilated, and non-reactive. follow up period and subsequent ESR and gested an association of fixed dilated pupil, The visual acuity at 1 month postopera- iris atrophy, and secondary glaucoma.1 tively was 6/9+ with −1.75/−1.50 × 125. The incidence of this syndrome is estimated Unfortunately 11 weeks postoperatively she at 5.8%, from pooled data on 445 eyes under- developed an inferior retinal detachment. No going penetrating keratoplasty for kerato- breaks were identified but she underwent a conus, of which 24 eyes developed a fixed cryobuckle procedure with an encircling dilated pupil.2 Davies and Ruben also found a band. Six months after her initial surgery she similar incidence.3 However, other more re- sees 6/12 wearing a contact lens correction of cent studies find no cases,4–6 and some even −2.25/−3.50 × 65. She is still troubled by glare question its continued existence. This may in and is somewhat unhappy with the cosmetic part reflect improved surgical technique and appearance of the eye. differing diagnostic criteria. Comment The pupil can become abnormally dilated following penetrating keratoplasty for kerato- The precise aetiology of this syndrome is conus, particularly if dilating drops are used. unknown; it has been suggested that iris ischaemia can develop if it is compressed There are three main groups of pupillary 3 Figure 2 2 Photomicrograph showing a dilatation. between the lens and cornea during surgery. segment of the superficial temporal artery This cannot be the explanation in patients with severely narrowed lumen (asterisk). The (1) A pupil with normal light and near undergoing deep lamellar keratoplasty. internal elastic lamina (a) is well preserved reaction which is at least 1.5 mm larger than Urrets-Zavalia syndrome has also been de- (elastica stain). The intima is considerably its fellow unoperated eye. It fully constricts scribed after penetrating keratoplasty for thickened (b) and shows tissue proliferation. with topical miotics. An incidence of approxi- other indications3 and after cataract surgery. There are no signs of necrosis, inflammation, mately 90% has been reported for this type of Urrets-Zavalia suggested that the strong or thrombus. abnormality.3 mydriasis produced by atropine at the time of
www.bjophthalmol.com 116 PostScript surgery brought the iris into contact with the après kératoplastie pour kératocone. Arch Peter Cackett, Clifford R Weir, Zaw peripheral cornea to produce peripheral ante- Ophthalmol (Paris) 1970;30:219–26. Minn-Din 1 Tuft SJ rior synechiae and glaucoma. Davis and 9 , Buckley RJ. Iris ischaemia following Tennent Institute of Ophthalmology, Gartnavel Ruben noted the condition was more com- penetrating keratoplasty for keratoconus General Hospital, Great Western Road, Glasgow mon in the absence of a peripheral iridotomy (Urrets-Zavalia syndrome). Cornea G12 0YN, UK and proposed a mechanism of relative pupil 1995;14:618–22. block.3 Naumann comments that in over 1000 Correspondence to: Dr Cackett cases of penetrating keratoplasty he has never Accepted for publication 12 July 2001 seen this condition and suggests that per- Asymptomatic oculopalatal References forming a peripheral iridotomy in phakic myoclonus: an unusual case patients is protective.4 Interestingly he always 1 Leigh RJ, Zee DS. The neurology of eye Oculopalatal myoclonus is characterised by movements. 3rd ed. New York: Oxford uses dilating drops. University Press, 1999. It has been suggested that the iris is in some rhythmic pendular vertical eye movements 2 Talks SJ, Elston JS. Oculopalatal myoclonus: way abnormal in keratoconus, supported by associated with synchronous contraction of eye movement studies, MRI findings and the the observation that these pupils remain the soft palate.1 It produces intractable difficulty of treatment. Eye 1997;11:19–24. dilated for longer periods following mydriasis oscillopsia,2 and is normally the result of 3 Matsuo F, Ajax ET. Palatal myoclonus and than in normal eyes.2 Keratoconic eyes seem brainstem haemorrhage.2 However, it is does denervation supersensitivity in the central 5 to hyperreact to application of mydriatics as not usually become manifest until several nervous system. Ann Neurol 1979; :72–8. far as speed of dilation and duration of effect, 4 Koeppen AH, Barron KD, Dentinger MP. months or even years later, with the longest Olivary hypertrophy: histochemical this observation is also seen the eyes of 3 2 recorded interval being 49 months. We demonstration of hydrolytic enzymes. patients with Down’s syndrome. present an unusual case of a patient who sus- Neurology 1980;30:471–80. An abnormality of the sympathetic nervous tained a brainstem haemorrhage following system in the keratoconic eye remains un- trauma. Eight years later he was incidentally proven. noted to have oculopalatal myoclonus, and Bilateral exudative retinopathy Davies and Ruben also suggest that direct surprisingly was asymptomatic. as the initial manifestation of iris trauma during surgery could result in strangulation of iris vessels in the mid- retinitis pigmentosa periphery and ischaemic paralysis of the Case report A Coats’-like retinopathy affects approxi- 3 sphincter pupillae. A 61 year old man was admitted to the neuro- mately 1–4% of cases of longstanding retinitis Tuft and Buckley suggest in the presence of surgery department following head trauma. A pigmentosa (RP).12As a presenting sign of RP, raised intraocular pressure, the low ocular computed tomography (CT) scan showed however, Coats’-like retinopathy is extremely rigidity of the keratoconic eye permits occlu- subarachnoid bleeding. An magnetic reso- rare.3 We present a case of bilateral exudative sion of the vessels at the root of iris within the nance image (MRI) revealed left frontal and retinopathy suggestive of Coats’ disease in a sclera, which results in iris ischaemia while 9 posterior parietal contusions and a small 12 year old boy in whom investigation preserving ciliary body function. brainstem haemorrhage. Following the head revealed previously undiagnosed RP. This case, the first to our knowledge, injury he complained of double vision on describes the Urrets-Zavalia syndrome follow- downgaze. Examination revealed bilateral Case report ing a lamellar keratoplasty. The compressive fourth cranial nerve palsies, which resolved A 12 year old male presented witha3week theory cannot play a part in this instance and history of blurred vision in both eyes. There it may lend support to the theory of an intrin- spontaneously. Nine months later the patient developed was no significant medical or family history. sic iris abnormality in keratoconus. Equally, Visual acuities were 6/120 in the right eye and the pain she experienced on the first postop- acute angle closure glaucoma in his right eye, which was unresponsive to medical therapy. 6/15 in the left eye. Anterior segment exam- erative evening may have been secondary to ination was normal. The posterior segment of raised intraocular pressure and perhaps sup- He subsequently underwent a right trab- ports the ischaemic theory.9 In either case, this eculectomy. Thereafter, his visual acuities syndrome is still poorly understood. were 6/18 in the right eye and 6/6 in the left eye, and he was reviewed annually at a Meg Minasian, William Ayliffe glaucoma clinic. Croydon Eye Unit, Mayday University Hospital While attending 8 years after his head NHS Trust, London Rd, Thornton Heath, Surrey CR7 7YE, UK injury, an audible click was heard emanating from the patient. He was unaware of this Correspondence to: Meg Minasian, Adnexal Unit, because of longstanding sensorineural deaf- Moorfields Eye Hospital, City Road, London ness. However, on further questioning his wife EC1V 2PD, UK; [email protected] stated that she had been aware of the clicking Accepted for publication 11 July 2001 for several months. Examination of the soft References palate revealed rhythmic contractions that 1 Urrets-Zavalia A. Fixed dilated pupil, iris were synchronised with the auditory clicking. atrophy and secondary glaucoma: a distinct There was a right unilateral vertical pendular clinical entity following penetrating nystagmus, although no nystagmus was keratoplasty for keratoconus. Am J noted in the left eye. A diagnosis of oculopala- Ophthalmol 1963;56:257–65. tal myoclonus secondary to the brainstem 2 Gasset AR. Fixed dilated pupil following penetrating keratoplasty in keratoconus haemorrhage 8 years previously was made. (Castroviejo syndrome). Ann Ophthalmol An MRI scan (T2 weighted images with 1977;9:623–8. contrast) was performed and found to be nor- 3 Davies PD, Ruben M. The paretic pupil: its mal. The patient was unaware of oscillopsia, incidence and aetiology after keratoplasty for presumably as a consequence of his reduced keratoconus. Br J Ophthalmol visual acuity secondary to the previous epi- 59 1975; :223–8. sode of angle closure glaucoma. As he was 4 Naumann GO. Iris ischaemia following penetrating keratoplasty for keratoconus asymptomatic no treatment was indicated. (Urrets-Zavalia syndrome). Cornea 1997;16:120. Comment 5 Krachmer JH, Feder RS, Belin MW. Keratoconus and related non-inflammatory Oculopalatal myoclonus is a rare condition corneal thinning disorders. Surv Ophthalmol normally resulting in intractable oscillopsia, 1984;28:293–322. thought to be caused by a lesion in the 6 Kirkness CM, Ficker LA, Steele ADMcG, et myoclonic triangle, which consists of the red al. The success of penetrating keratoplasty for nucleus, the ipsilateral inferior olive, and the Figure 1 (A) Fundus photograph of the keratoconus. Eye 1990;4:673–88. contralateral dentate nucleus.4 To our knowl- Pouliquen Y right eye showing subretinal exudation, 7 , Ginmaraes R, Petroutsos G, et edge, this is the first reported case of al. Le syndrome d’Urrets-Zavalia: existe-t-il serous retinal detachment, and telangiectatic encore? J Fr Ophtalmol 1983;6:325–6. asymptomatic oculopalatal myoclonus. It also retinal vessels. (B) Fundus photograph of the 8 Pouliquen Y, Bernard J, Mezarik B. A propos illustrates that the latency period may be left eye showing mottled granularity of the de 4 cas de mydriase aiguë irido-atrophiante longer than that previously described. retinal pigment epithelium.
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consider an underlying diagnosis of retinitis diabetic patients. We report a case of asym- pigmentosa in any patient presenting a metric diabetic retinopathy with posterior picture of bilateral exudative retinopathy. segment neovascularisation due to OIS asso- ciated with critical ipsilateral carotid stenosis Acknowledgments where the neovascularisation resolved after Support provided by the International Award of carotid endarterectomy. Merit in Retina Research, Houston, Texas (JA Shields); Macula Foundation (CL Shields), and Eye Case report Tumor Research Foundation, Philadelphia, PA, USA. A 50 year old woman presented in May 1996 Arun D Singh, Carol L Shields, with left sided weakness. She had hypercho- Jerry A Shields lesterolaemia, hypertension, a family history Oncology Service, Wills Eye Hospital, USA of vascular disease, and was a smoker. She was found to be diabetic with peripheral reti- Alan Goldfeder nal ischaemia and disc neovascularisation in Thomas Jefferson University, Philadelphia and the right eye, and minimal retinal ischaemia Ophthalmic Physicians, Union, New Jersey, USA in the left eye (Fig 1). Her visual acuities were 6/12 in the right eye and 6/9 on the left. There Correspondence to: Arun D Singh, MD, Oncology was no anterior segment neovascularisation Service, Wills Eye Hospital, 900 Walnut Street, Philadelphia, PA 19107, USA; in either eye. Carotid Doppler and carotid [email protected] angiography showed critical stenosis at the Accepted for publication 16 July 2001 origin of the right internal carotid artery. The right middle cerebral artery branches were References visualised as a result of retrograde flow 1 Kajiwara Y. Ocular complications of retinitis through the ophthalmic artery. The left inter- pigmentosa. Association with Coats’ nal carotid artery was narrowed by 50% and syndrome. Jpn J Clin Ophthalmol there were no collaterals to the right hemi- 1980;34:947–55. 2 Pruett RC. Retinitis pigmentosa: clinical sphere (Fig 2). Fluorescein angiography re- observations and correlations. Trans Am vealed a prolonged transit time with slow fill- Ophthalmol Soc 1983; 81:693–735. ing of choroidal and retinal vasculature, Figure 2 (A) Fluorescein angiogram of the 3 Kim RY, Kearney JJ. Coats-type retinitis peripheral retinal capillary closure, and leak- right eye showing retinal ischaemia with pigmentosa in a 4-year-old child. Am J age from the disc neovascularisation. 114 adjacent telangiectasia. (B) Scotopic Ophthalmol 1997; :846–8. One year later the optic disc neovascularisa- 4 Zamorani G. Una rara associazone di electroretinogram showing isoelectric tion and retinal ischaemia were unchanged retinite di Coats con retinite pigmentosa. Gior with no iris neovascularisation. In April 1997 response in both eyes. Ital Oftalmol 1956;9:429–43. 5 Khan JA, Ide CH, Strickland MP. Coats’-type she underwent an uneventful right carotid retinitis pigmentosa. Surv Ophthalmol endarterectomy. Two months later she devel- both eyes showed extensive subretinal exuda- 1988;32:317–32. oped clinically significant macular oedema in tion, serous retinal detachment, and overlying 6 Witschel H. Retinopathia pigmentosa and the right eye that was treated with focal argon retinal telangiectasia (Fig 1A). There was “morbus Coats”. Klin Monatsbl Augenheilkd laser photocoagulation. cystoid macular oedema with a lamellar 1974;164:405–11. Six months later the maculopathy had macular hole in the left eye. The optic discs resolved and 14 months after surgery there appeared normal. Additionally, mottled Resolution of proliferative was complete resolution of the optic disc neo- granularity of the retinal pigment epithelium venous stasis retinopathy after vascularisation. Three years after surgery the (RPE) was noted in the mid-periphery of both right eye had a visual acuity of 6/9, a near retinas (Fig 1B). Upon further questioning, he carotid endarterectomy normal fluorescein angiogram transit time, admitted to night blindness. Ocular ischaemic syndrome (OIS) may minimal peripheral retinal ischaemia, and no A fluorescein angiogram confirmed retinal present as an asymmetric retinopathy in posterior segment neovascularisation. telangiectasia, serous retinal detachment, and macular oedema (Fig 2A). An electroretino- gram (ERG) showed an isoelectric response under both scotopic and photopic conditions (Fig 2B). Visual field testing revealed marked constriction in both eyes. A diagnosis of retinal telangiectasia, exuda- tive retinopathy, and retinitis pigmentosa was made and the areas of most severe tel- angiectasia were treated with retinal cryo- therapy. One year later the retinal telangiecta- sia had mostly resolved, the exudation was slightly less extensive and the visual acuity was unchanged. Comment The association between retinitis pigmentosa and exudative retinopathy was first described in 19564 and has been termed a “Coats’-like RP.”5 Various studies have suggested that 1–4% of RP cases will show such a response.12This entity differs from true Coats’ disease in that Coats’-like RP often occurs bilaterally, has no sex predisposition, and shows diffuse pig- mented alterations in both fundi.56The cause is unknown but it may represent a vasodila- tory response to toxic products of photoreceptor/RPE degeneration.2 Our case is unusual in that almost all previous reported cases have occurred in the setting of long- standing RP.23 Our patient had never con- Figure 1 Presenting fundus photograph showing disc neovascularisation (A) with sulted an ophthalmologist despite being night corresponding fluorescein angiogram showing leakage from these vessels (B). The blind and having markedly constricted visual neovascularisation has resolved 14 months after surgery (C) and is confirmed on fluorescein fields. We recommend that ophthalmologists angiography (D).
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Comment neovascular glaucoma.8–10 The European Ca- after carotid endarterectomy. Am J Ocular ischaemic syndrome (OIS) is charac- rotid Surgery Trial showed that the risk of Ophthalmol 1976;81:600–2. Kearns TP terised in the anterior segment by flare and ischaemic stroke in symptomatic patients 8 , Younge BR, Piepgras DG. with 70–99% carotid stenosis with medical Resolution of venous stasis retinopathy after initial hypotony,with later iris neovascularisa- carotid endarterectomy. Mayo Clin Proc tion. Retinopathy with neovascular prolifera- treatment was only 20% over 3 years and CEA 1980;55:342–6. tion occurs in the fundus because of chronic lowered this by 50%. Based on the results of 9 Ino-ue M, Azumi A, Kaijura-Tsukahara Y, et hypoperfusion. The development of neovascu- this a risk factor score suggested that a al. Ocular ischemic syndrome in diabetic lar glaucoma can lead to permanent cerebral rather than an ocular event had a patients. Jpn J Ophthalmol 1999;43:31–5. blindness.12 In the diabetic patient OIS is greater risk for stroke on medical treatment 10 Geroulakos G, Bothchway L, Pai V, et al. superimposed on any pre-existing diabetic and would therefore derive greater benefit Effect of carotid endarterectomy on the ocular retinopathy, and markedly asymmetric retin- from surgery.2 circulation and on ocular symptoms unrelated In the absence of iris neovascularisation to emboli. Eur J Vasc Endovasc Surg opathy should prompt a search for underlying 1996;11:359–63. ischaemia from carotid occlusive disease. Dia- and severe peripheral retinal ischaemia the betic patients with marked proliferative ocular changes in patients with OIS can be changes require treatment with panretinal monitored closely for the development of iris Identifying the proportion of age photocoagulation (PRP), which has been neovascularisation but the retinal vascularisa- related macular degeneration tion may not require early treatment with shown to reduce the risk of severe visual loss patients who would benefit from and neovascular glaucoma. However, there is PRP. photodynamic therapy with no clear evidence for the benefit of PRP in Christina A Rennie, Declan W Flanagan patients with OIS. In one study only 36% of verteporfin (Visudyne) OIS patients with iris neovascularisation Department of Ophthalmology, Addenbrooke’s Hospital, Cambridge, UK responded to PRP,which may be due to uveal Verteporfin has recently been licensed for the rather than retinal ischaemia.34 In the case treatment of subfoveal exudative cases of age Correspondence to: Dr C Rennie, Department of related macular degeneration (AMD); however, presented the patient was not treated with Ophthalmology, Princess Margaret Hospital, Okus it is not clear how many patients would immediate PRP but reviewed regularly. The Road, Swindon, Wilts, SN1 4JU, UK 12 disc new vessels did not progress in the year Accepted for publication 23 July 2001 actually benefit from this treatment. This before carotid endarterectomy and there was question has far reaching implications in terms References no immediate threat to vision. of verteporfin’s introduction into the National Carotid stenosis can result in changes in the 1 Brown G, Magargal L. The ocular ischaemic Health Service in the United Kingdom. ophthalmic artery blood flow ranging from syndrome. Clinical, fluorescein angiographic and carotid angiographic features. Int Case report reduced antegrade to reversal of flow. If there Ophthalmol 1988;11:239–51. We have recently looked at a cohort of 1418 is inadequate crossflow in the circle of Willis 2 Malhotra R, Gregory-Evans K. Management new referrals (out of a possible 1481 (95.7%)) from the contralateral internal carotid, re- of ocular ischaemic syndrome. Br J seen in the 166 consultant outpatient clinics versal of flow occurs in the ophthalmic artery Ophthalmol 2000;84:1428–31. at Southampton Eye Unit, between 1 Decem- as a consequence of a collateral circulation 3 Mizener JB, Podhajsky P, Hayreh SS. Ocular 5 ber 2000 and 31 January 2001. Diagnoses from branches of the external carotid artery. ischaemic syndrome. Ophthalmology were obtained from the consultant’s letter to Although some series show no correlation 1997;104:859–64. 4 Sivalingam A, Brown GC, Magargal LE. The the referring doctor following the clinic visit between direction of flow and the severity of ocular ischemic syndrome. III. Visual to obtain the spectrum of diagnoses made. OIS Kerty et al in a study of 45 patients found prognosis and the effect of treatment. Int When two eyes were similarly affected this that only reversal of flow was associated with Ophthalmol 1991;15:15–20. 6 was recorded as a single diagnostic event. structural changes of OIS. Riordan-Eva P 5 , Restori M, Hamilton AMP, et Cataract related diagnoses3 were found to One similar case exists in the literature al. Orbital ultrasound in the ocular ischaemic be most frequent, accounting for 28.8% (597) where neovascularisation resolved within sev- syndrome. Eye 1994;8:93–6. 7 of the total. This was followed by retinal eral days of carotid endarterectomy (CEA). 6 Kerty E, Eide N, Horven I. Ocular disease3 at 23.4% (485). Other case reports also show that the retin- hemodynamic changes in patients with high-grade carotid occlusive disease and Within the retinal disease group AMD was opathy without neovascularisation can im- development of chronic ocular ischaemia II. the single most frequent diagnosis even prove following surgery. However, the benefit Clinical findings. Acta Ophthalmol Scand though it may not have been the primary rea- of carotid endarterectomy in patients with 1995;73:72–6. son for referral, accounting for 22.3% (108) of ocular ischaemic syndrome is not quantified Neupert JR 7 , Brubaker RF, Kearns TP, et al. the 485 retinal disease cases recorded. Of the and it has never been shown to reverse Rapid resolution of venous stasis retinopathy 108 AMD patients identified, 62% (67) were female and 38% (41) male, the majority being above the age of 75 (90.7%). Approximately 78% (84) of the total number of patients had AMD affecting both eyes with unilateral involvement in the remaining 22% (24). Of the 108, most were not felt to need further investigation, having either estab- lished and untreatable disease or mild changes. Only 13% (14) underwent further investigation with fluorescein angiography. Of these, four were thought to be possibly suitable for verteporfin treatment with only one fully meeting the criteria for treatment, having a predominantly classical subfoveal membrane.12 Co-existing ocular diseases such as cataract and glaucoma were treated in 49% (53) of the 108 patients, cataract extraction predominat- ing (70% (37)). The majority of the 107 patients (77) who did not receive verteporfin therapy did not require or were not suitable for any further assistance for their AMD. The remainder (30) were assessed for low vision aids and/or regis- tered as partially sighted/blind. Comment Photodynamic therapy with verteporfin has Figure 2 Angiography showing narrowing of the right internal carotid artery (A, arrow) and caused much excitement, as it is heralded as a angiogram of the left side (B) revealing lack of crossflow to the right cerebral hemisphere breakthrough in the treatment of exudative allowing the development of collateral circulation via the ophthalmic artery. AMD.45A recent editorial in the BMJ suggested
www.bjophthalmol.com PostScript 119 that 20–30% of the 200 000 cases of exudative neovascularisation in pathologic myopia, All patients had effective anaesthesia and AMD that present to ophthalmologists each ocular histoplasmosis syndrome, angioid akinesia for the surgical procedure. None year in the United States would benefit from streaks, and idiopathic causes. Arch complained of pain. Top up of anaesthesia was 118 such photodynamic therapy.6 Southampton Ophthalmol 2000; :327–36. not required in any case. Twenty eight patients 8 Mones J, for the Verteporfin in Photodynamic Eye Unit serves approximately 570 000 people Therapy (VIP) Study Group. Photodynamic had complete or partial ptosis. as part of its main catchment area, correspond- therapy with verteporfin of the subfoveal Subconjunctival haemorrhage extending ing to approximately 1% of the UK population, choroidal neovascularisation in age-related more than one quadrant occurred in one and produced only one person over the 2 macular degeneration: study design and patient, but this did not interfere with month study period suitable for treatment with baseline characteristics in the VIP randomized surgery. None had chemosis. verteporfin by the strict criteria for its use.12 clinical trials. Invest Ophthalmol Vis Sci The period studied was before the awareness of 1999;40:S321. Comment 9 Chisholm IH, Bird AC, Grey RHB, et al. photodynamic therapy was fully developed and Sub-Tenon’s local anaesthesia is a well estab- Age-related macular degeneration best clinical lished technique for ophthalmic surgery. represents an unselected group of patients practice guidelines. Trans Roy Coll having some degree of AMD. Subsequent stud- Ophthalmol 2000:3–19. Although the Venflon cannula does have a ies might show a higher proportion of suitable sharp needle, it is used simply as an intro- patients once their referral is with a view for A new technique for delivering ducer to place the blunt plastic cannula in the verteporfin treatment. Between August 2000 correct tissue plane. The needle tip is kept and April 2001 a total of 24 patients were sub-Tenon’s anaesthesia in under direct visualisation at all times. Thus assessed for verteporfin therapy resulting in ophthalmic surgery there is minimal risk of ocular perforation with this technique. seven receiving treatment, in keeping with the Sub-Tenon’s local anaesthesia has become an 4:1 ratio of those assessed and treated in the 2 Venflon cannulas are used for intravenous accepted technique for anterior and posterior delivery of drugs and fluid so are readily month study. While it is difficult to extrapolate segment eye surgery.1–5 It is a safe, quick, and from such a small number it would seem that available, inexpensive, and disposable. Sub- effective method of local anaesthesia. How- Tenon’s cannulas in current use are special- the number likely to benefit from verteporfin ever, it requires a certain amount of skill for ised cannulas and therefore more costly than treatment may well be smaller than suggested dissection into the sub-Tenon’s space. This intravenous cannulas. even if the treatment criteria was extended to dissection can lead to bleeding and chemosis. We describe a modification of the current include occult, myopic, and idiopathic We describe a modification of the current 78 technique of sub-Tenon’s anaesthesia which lesions. technique of sub-Tenon’s anaesthesia which simplifies the method using an intravenous Even with the addition of verteporfin aims to simplify the method of local anaes- cannula. We predict that this method is easier therapy to the ranks of the treatment modali- thetic delivery, avoid bleeding, and chemosis to learn and that it maintains the efficacy of ties available, the vast majority of AMD while maintaining effective anaesthesia. patients are still considered untreatable if the this type of anaesthesia without compromis- treatment criteria are observed.12 Rehabilita- Case report ing safety. tion in the form of low vision aids, registration Fifty consecutive patients undergoing ante- Sandip Amin as partially sighted or blind, and the treat- rior segment surgery scheduled for local Department of Anaesthesia, Moorfields Eye ment of co-existing ocular disease remains anaesthesia were recruited for this study. Hospital, City Road, London EC1V 2PD, UK the mainstay of help that the ophthalmologist For this procedure, a 22 gauge Venflon can offer.9 However, the interest created and standard intravenous cannula was used. The Miriam Minihan accepted value of verteporfin should not be conjunctiva was anaesthetised with topical Department of Ophthalmology, St Thomas’s underestimated as it represents a new and amethocaine 1%. A Barraquet speculum was Hospital, Lambeth Palace Road, London SE1 7EH, non-destructive approach to the problem (in inserted. The conjunctiva was grasped 5 mm UK contrast with laser photocoagulation) and the from the limbus using toothed forceps. Under Sarit Lesnik-Oberstein first of a novel treatment option likely to be direct visualisation the tip of a 22 gauge Ven- Department of Ophthalmology, Moorfields Eye joined by others in the not too distant future. flon was used to introduce the plastic cannula Hospital, City Road, London EC1V 2PD, UK under the conjunctiva and Tenon’s fascia N Mandal, I H Chisholm (keeping the needle tip visible at all times) Caroline Carr Southampton Eye Unit (Fig 1A). The plastic cannula was advanced Department of Anaesthesia, Moorfields Eye over the needle, which was drawn back and Hospital, City Road, London EC1V 2PD, UK Correspondence to: Nakul Mandal, c/o Sheila removed (Fig 1B). Four millilitres of ligno- Davies, Southampton Eye Unit, Southampton caine 2% with 30 international units (IU)/ml Correspondence to: Sandip Amin; SO16 6YD, UK; [email protected] [email protected] Accepted for publication 25 July 2001 of hyalase was then injected through the Accepted for publication 13 August 2001 plastic cannula (Fig 1C). References All 50 patients had anterior segment surgery. References 1 Treatment of Age-related Macular Forty six were cataract operations with poste- 1 Stevens JD. A new local anaesthesia Degeneration with Photodynamic Therapy rior chamber lens implant, and four were technique for cataract extraction by one (TAP) Study Group. Verteporfin (Visudyne) phacotrabeculectomies. None experienced ex- quadrant sub-Tenon’s infiltration. Br J therapy of subfoveal choroidal cessive discomfort on delivery of the block. All Ophthalmol 1992;76:670–4. Mein CE neovascularization in AMD: one-year results local anaesthetic blocks were performed by one 2 , Woodcock MG. Local anaesthesia for vitreoretinal surgery. Retina 1990;10:47–9. of two randomised clinical trials-TAP Report 1. operator and no complication which prevented Arch Ophthalmol 1999;117:1329–45. 3 Hansen EA, Mein CE, Mazzoli R. Ocular 2 Treatment of Age-related Macular surgery occurred. No patient who was sched- anaesthesia for cataract surgery: a direct Degeneration with Photodynamic Therapy uled for local anaesthesia was considered sub-Tenon’s approach. Ophthalmic Surg (TAP) Study Group. Verteporfin (Visudyne) unsuitable for this technique. 1990;21:696–9. therapy of subfoveal choroidal neovascularization in AMD: two-year results of two randomised clinical trials-TAP Report 2. Arch Ophthalmol 2001;119:198–207. 3 Ellwein LB, Friedlin V, McBean AM, et al. Use of eye care services among the 1991 Medicare population. Ophthalmology 1996;103:1732–43. 4 Stokkermans TJW. Treatment of age-related macular degeneration. Clin Eye Vis Care 2000;12:15–35. 5 Margherio RR, Margherio AR, DeSantis ME. Laser treatment with verteporfin therapy and its potential impact on retinal practices. Retina 2000;20:325–30. 6 Bressler NM, Gills JP. Age-related macular degeneration: new hope for a common problem comes from photodynamic therapy. BMJ 2000;321:1425–7. 7 Sickenberg M, Schmidt-Erfuth U, et al.A preliminary study of photodynamic therapy using verteporfin for choroidal Figure 1 New technique for delivering sub-Tenon’s anaesthesia injection.
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4 Li HK, Abouleish A, Grady J, et al. represent the “true” pressure value that is at propriate in order to decide on the necessity of Sub-Tenon’s injection for local anaesthesia in the tip of the cannula. If there were a barrier a conversion formula. posterior segment surgery. Ophthalmology inside the cannula the reading on the monitor Further, the variability of differences is 2000;107:41–7. would also be stable but would not represent large, which is probably the result of errors in 5 Roman SJ, Chong Sit DA, Boureau CM, et al. Sub-Tenon’s anaesthesia: an efficient and safe the pressure at the tip. There are many pitfalls the intracameral measurement of IOP. technique. Br J Ophthalmol 1997;81:673–6. in pressure measurements by thin tubes that Regression lines with a small non-significant we know from our own studies.34Minute air slope (0.38 mm Hg IOP difference per 0.1 mm bubbles or tiny particles influence the result a cornea thickness in the article by Feltgen et al MAILBOX great deal. If we want to know that a display may occur in both situations where variability reading represents the quantity in question is both high and low. Only, in the latter case, then we have to guarantee that the measure- when—as a consequence of the small IOP measurement and central ment system has the opportunity to react variability—the confidence interval for the freely to changes in the quantity. This guaran- slope is narrow, may this be interpreted in the corneal thickness tee can be obtained by feeding a known signal way that the covariate included in the model In the recent paper by Feltgen and to the input of the system and by observing (that is, CCT) has no effect. If the variability is colleagues,1 the intraocular pressure (IOP) the output. If the output reacts in the high and the slope is approximately 0, this was measured by Goldmann applanation expected way then the guarantee is given. may lead to the conclusion that IOP measure- tonometry and by using a cannula inserted Ehlers et al5 realised this in their rabbit experi- ment is inappropriate because of too large an into the anterior chamber connected with a ments and we in electrophysiology.6–9 As long error. This conclusion is allowed if no other pressure transducer. Thus, the measurement as this demand is not met the results are not essential covariates were overlooked. If vari- took place omitting a possible influence of the definitive, giving cause for criticism and lead- ability is high and the slope of the regression cornea on the result. Marx et al2 believed that ing to misinterpretations. line is near 0, a large p value may not be inter- by intracameral measurement the “true” Feltgen et al write in their paper (p 86): preted as a proof of no effect of the covariate intraocular pressure may be measured. Felt- “ . . .however, we believe intracamerally considered in the regression model. For better gen et al share his opinion. They believe, measured IOP values reflect the ‘true’ IOP interpretation of the results a confidence therefore, that they have compared the more accurately.” Scientific facts should not interval for the estimated slope would have intraocular pressure measured with and with- be a matter of belief. The belief of the authors been much more appropriate thanapvalue. out the possible influence of the cornea. in the values they measured is not justified. In As a consequence, the differences between Feltgen et al write in their conclusion: the study under discussion their figure 2 measurements from applanation tonometry “There is no systematic error of applanation shows the scatter plot of the pressure differ- and a reference method, like the intraocular tonometry with increasing central corneal ences versus central corneal thickness. From hydrostatic pressure done by Ehlers et al, thickness (CCT). Therefore it is inadequate to this diagram and from their statistical calcu- should be evaluated first. If measurements by recalculate IOP based on regression formula lations the authors draw their conclusions. applanatory IOP are highly correlated with of applanatory IOP versus CCT.” They base Their results are quite different from those of measurements by the reference method a their conclusion on their results. In our opin- Ehlers et al5 shown in figure 4 of their paper. conversion formula may be derived from ion their paper shows the following method- Thus we must compare these two data sets. To linear regression. Under the assumption of ological deficits: (1) Both methods used for facilitate this task, we have digitised the data small variability of residuals (difference be- measuring IOP are not up to the demands of presented in the figures of Feltgen et al and of tween observed value and regression line)— the scientific technique of measurement; (2) Ehlers et al. They are shown here in Figures 1 that is, a satisfactory goodness of fit (for their intracamerally measured IOP values do and 2 on the same scale. The difference is example, r2>60%), results may lead to the not reflect the true IOP because of bias; (3) a striking. recommendation of the use of a conversion non-significant regression coefficient does not Let’s first consider a possible reason from formula. In contrast, Feltgen et al report an r2 prove that the slope is actually 0 and, the physical point of view. Ehlers et al5 reduced of 0.2%. Only for small residuals, a slope therefore, by a non-significant regression the pressure measurement to a basic physical approximately 0, and a confidence interval coefficient it is not proved that applanatory quantity, here to the length of a water column. with limits near to 0, may the recommen- readings are not influenced by CCT; (4) the We can, therefore, trust the results of Ehlers et dation that a conversion formula is not neces- goodness of fit of the linear regression model al more than the results of Feltgen et al who sary be given. is insufficient; and (5) an important covariate used a pressure transducer which has a zero Moreover, the large variability in IOP differ- (true IOP value) was omitted in the linear point fluctuation up to 4.5 mm Hg (Abbott ences may occur because Feltgen et al did not regression. We would like to discuss these GmbH, data file). It is recommended also by adjust for “true” intraocular hydrostatic pres- points in detail. the manufacturer that the zero point of the sure as Ehlers et al did. Since Ehlers et al In the study of Feltgen et al the only measurement system has to be determined calculated separate linear regression models criterion for the quality of measurement is the for each patient by comparison with a water for 10 mm Hg and 30 mm Hg which resulted stability of the readings on the monitor. How- column (Dr Beer, Abbott GmbH, Wiesbaden, in different intercepts and slope parameters, ever, it is not sufficient to conclude from the personal communication). This procedure is this might be another source of variation in presence of stability that the scale readings not described by Feltgen et al. the IOP differences from Feltgen et al which Therefore, none of the methods used in the were unadjusted. article by Feltgen et al may be called a We hope our arguments are convincing and reference method and all methods may be ask that you bring them to the attention of 10 prone to error and bias. Hence, analysis of dif- your readers. ferences in IOP between these models is inap- Richard Stodtmeister 5 St Elisabeth Hospital Rodalben (Palatinate), 10 Turnstrasse 24, D-66953 Pirmasens, Germany 0 Martina Kron, Wilhelm Gaus (1975) (mm Hg) 5 University of Ulm, Department of Biometry and Medical Documentation, Schwabstrasse 13, et al –5 D-89075 Ulm, Germany 0
Ehlers –10 Correspondence to: Professor Dr med Richard Correction value according to 400 500 600 700 Stodtmeister; [email protected] CCT (µm) –5 References
Figure 1 Correction value (mm Hg) Feltgen N Dependence of differences in IOP –10 1 , Leifert D, Funk J. Correlation measurements from CCT. Data of figure 2 of 400 500 600 700 between central corneal thickness, applanation tonometry, and direct Feltgen et al obtained by digitisation; 68 of CCT (µm) the 73 data points could be identified. The intracameral IOP readings. Br J Ophthalmol 85 four outliers shown by Feltgen et al as open Figure 2 Dependence of differences in IOP 2001; :85–7. 2 Marx W, Madjlessi F, Reinhard T, et al. [More circles are omitted. These outliers would have measurements from CCT. Data of figure 4 of than four years’ experience with electronic 5 made the use of the same scale in both Ehlers et al obtained by digitisation. All data intraocular needle tonometry] Mehr als vier diagrams more difficult. Thus n = 64. Same points could be identified. Thusn=29. Jahre Erfahrung mit der elektronischen scale as in Figure 2. Same scale as in Figure 1. intraokularen Nadel-Druckmessung bei
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irregularen Hornhauten. Ophthalmologe his trial on human eyes. We are also missing Annual subscription £25. Free to workers in 1999;96:498–502. any information about the cannula size. Addi- developing countries. 3 Stodtmeister R, Kästner R, Pillunat LE. tionally, the device used resembles an “open Saugnapfmethoden. In: Straub W, Kroll P, system” where fluid could circulate through Küchle HJ, eds. Augenärztliche International Centre for Eye Untersuchungsmethoden. 1st ed.Stuttgart: the anterior chamber and trabecular mesh- Health Ferdinand Enke, 1995:436–61. work. This can generate a noticeable change in The International Centre for Eye Health has 4 Stodtmeister R, Hornberger M, Hofer M, et intraocular pressure. 2 published a new edition of the Standard List of al. Okulo-Oszillo-Dynamographie nach Ulrich Ehlers et al measured IOP in patients with Medicines, Equipment, Instruments and Optical und Ulrich: Ergebnisse bei Augengesunden. an acute eye disease (glaucoma patients Klin Monatsbl Augenheilkd Supplies (2001) for eye care services in requiring surgery) and cataract patients. He developing countries. It is compiled by the 1988;192:219–33. changed the IOP to 10 and 30 mm Hg. This 5 Ehlers N, Bramsen T, Sperling S. Applanation Task Force of the International Agengy for the tonometry and central corneal thickness. Acta method is questionable especially in glau- Prevention of Blindness. Further details: Sue Ophthalmol (Copenh) 1975;53:34–43. coma patients, because an acute IOP change Stevens, International Centre for Eye Health, 6 Stodtmeister R, Wilmanns I. Bandpass could also entail endothelial alterations which 11–43 Bath Street, London EC1V 9EL, UK measurements in the electroretinographic could alter CCT. Unfortunately, he didn’t (tel: +44 (0) 20 7608 6910; email: electrode circuit. Albrecht Von Graefes Arch measure the CCT after IOP change. We have [email protected]). Klin Exp Ophthalmol 1978;208:263–7. no information about the influence of IOP 7 Stodtmeister R, Wilmanns I. Changes of the alterations on CCT. current pathways in the eye due to coating Leonhard Klein Award 2002 In summary, the above mentioned study agents during electroretinography. Albrecht To promote ophthalmic surgery the Leonhard Von Graefes Arch Klin Exp Ophthalmol gives a hint on the influence of CCT on IOP 1978;208:255–60. measurement, but does not prove this as- Klein Foundation bestows the Leonhard Klein 8 Stodtmeister R, Wilmanns I, Koenig A, et al. sumption. It is amazing that within the last 25 Award 2002 for innovative, scientific works in EEG-Registrierung beim Hirntod. Prakt Anaesth years nearly 50 published papers refer to the the field of development and application of 1978;13:446–9. Ehlers study2 without checking the results by microsurgical instruments, as well as for 9 Wilmanns I, Stodtmeister R. Ein neues intracameral measurement themselves. microsurgical operating techniques. Verfahren zur Kalibrierung The award is endowed with 15.000& and elektrophysiologischer All papers measuring CCT and applanatory IOP renouncing intracameral measurement can be conferred to an individual person as Untersuchungseinheiten. Albrecht Von Graefes well as to a group of researchers. The prize Arch Klin Exp Ophthalmol 1977;205:33–9. described an increasing IOP with increasing CCT. We could also confirm this finding in our sum must be spent for research in the field of × opthalmic surgery. Authors’ reply study (y = 14.5 + 8.4 CCT, where y is applanatory IOP in mm Hg). Of course, it Individual and third party applications are In reply to the comments of Stodtmeister and would be easiest to claim the cornea for this accepted. Five copies of the works must be colleagues on our recent paper,1 we won’t argue correlation. But it is also conceivable that eyes submitted in either English or German. The about the correlation between central corneal with thick corneas (for example, OHT) have a deadline for applications is 31 March 2002. thickness (CCT) and intraocular pressure reduced ocular outflow facility and conse- Applications should be sent to: Stifterverband (IOP), but we mistrust the clinical application quently elevated IOP—for instance, because für die Deutsche Wissenschaft e.V., Frau Dr of correcting factors. Stodtmeister et al compare of a “thick” trabecular meshwork. Marilen Macher, Postfach 164460, D-45224 our study to that of Ehlers et al2 which is often With the present study 1 we tried to find out Essen, Germany. cited to prove an influence of corneal thickness if the above recommended correcting factors on applanatory measurement. are clinically applicable or not. According to Second Sight In our paper simultaneous IOP measure- our findings they are not. We found quite Second Sight, a UK based charity whose aims ment by applanation and intracameral to- variable and unpredictable differences be- are to eliminate the backlog of cataract blind nometry was performed. Assuming a normal tween intraocular pressure and applanatory in India by the year 2020 and to establish CCT of 520 µm, an IOP correction for every 10 measurement in an individual patient. Inter- strong links between Indian and British µm change in corneal thickness is recom- estingly, the same results can be found in the ophthalmologists, is regularly sending volun- mended. But in the Ehlers paper, there are Ehlers study.2 Therefore, we renew our warn- teer surgeons to India. Details can be found at some confusing arguments. ing to recalculate the IOP depending on the charity website (www.secondsight.org.uk) Ehlers et al2 describe a very good correlation central corneal thickness. or by contacting Dr Lucy Mathen between direct and intracameral IOP ([email protected]). measurement (correlation coefficient ap- Nicolas Feltgen, Jens Funk proximated 1). Unfortunately, they didn’t give Department of Ophthalmology, SPecific Eye ConditionS (SPECS) the measured IOP values. In figure 2, the Albert-Ludwigs-University Freiburg, Germany; SPecific Eye ConditionS (SPECS) is a not for slopes of correlation lines at different CCT are [email protected] profit organisation which acts as an umbrella presented for rabbits (not for human eyes!). References organisation for support groups of any condi- The increase of the slopes are less than 45°. tions or syndrome with an integral eye disor- 3 1 Feltgen N, Leifert D, Funk J. Correlation With the paper of Bland and Altman in mind, between central corneal thickness, der. SPECS represents over fifty different a minor methodological agreement is very applanation tonometry, and direct organisations related to eye disorders ranging likely. It is therefore not allowed to recalculate intracameral IOP readings. Br J Ophthalmol from conditions that are relatively common to the values P10 and P30 (applanatory versus 2001;85:85–7. very rare syndromes. We also include groups intracamerally IOP, measured at an adjusted 2 Ehlers N, Bramson T, Sperling S. Applanation who offer support of a more general nature to IOP of 10 and 30 mm Hg) for a relevant IOP tonometry and central corneal thickness. Acta visually impaired and blind people. Support 53 level of 20 mm Hg (P20). It is indeed very Ophthalmol (Copenh) 1975; :34–43. groups meet regularly in the Boardroom at 3 Bland JM, Altman DG. Statistical methods for interesting that the group didn’t measure at Moorfields Eye Hospital to offer support to an IOP level of 20 mm Hg. assessing agreement between two methods of clinical measurement. Lancet 1986;1: each other, share experiences and explore new The equipment for intracameral measure- 307–10. ways of working together. The web site ment is comparable to our device. We also www.eyeconditions.org.uk acts as a portal calibrated the transducer before each giving direct access to support groups own measurement. When we tested our device on NOTICES sites. The SPECS web page is a valuable enucleated human eyes in a preclinical study, resource for professionals and may also be of a very sensitive change of IOP values was interest to people with a visual impairment or noted when touching the eyeball. We there- Onchocerciasis who are blind. For further details about fore decided not to measure the IOP simulta- The latest issue of Community Eye Health (No SPECS contact: Kay Parkinson, SPECS Devel- neously. We also confirmed these findings in 38) discusses onchocerciasis and the impact opment Officer (tel: +44 (0)1803 524238; vivo. For these reasons, we expected an of interventions, with an editorial by Bjorn email: [email protected]; www.eyecon- unpredictable increase of applanatory Thylefors, former director of the Programme ditions.org.uk). measurement during intracamerally IOP in for the Prevention of Blindness and Deafness, the study of Ehlers.2 Unfortunately, there is no WHO. For further information please contact 4th International Conference on comment about this problem. Community Eye Health, International Centre for Stodtmeister and colleagues pointed out Eye Health, Institute of Ophthalmology, the Adjuvant Therapy of the “pitfalls in pressure measurement” (bub- 11–43 Bath Street, London EC1V 9EL. (tel: Malignant Melanoma bles or tiny particles) without mentioning +44 (0) 20 7608 6909/6910/6923; fax: +44 (0) The 4th International Conference on the that Ehlers had not solved these problems in 7250 3207; email: [email protected]). adjuvant therapy of malignant melanoma will
www.bjophthalmol.com 122 PostScript
be held at The Royal College of Physicians, Secretariat, C/- ICMS Australia Pty Ltd, GPO International Society for Behçet’s London on 15–16 March 2002. Further de- Box 2609, Sydney, NSW 2001, Australia (tel: Disease tails: Conference Secretariat, CCI Ltd, 2 Palm- +61 2 9241 1478; fax: +61 2 9251 3552; The 10th International Congress on Behçet’s erston Court, Palmerston Way, London email: [email protected]; website: Disease will be held in Berlin 27–29 June SW8 4AJ, UK (tel: + 44 (0) 20 7720 0600; fax: www.ophthalmology.aust.com). + 44 (0) 20 7720 7177; email: 2002. Further details: Professor Ch Zouboulis [email protected]: website: (email: [email protected]). www.confcomm.co.uk/Melanoma). 12th Meeting of the European EUPO 2002 Course Retina Association for the Study of Singapore National Eye Centre A course on retina will be held on 15–17 Diabetic Eye Complications 5th International Meeting March 2002 at Erlangen, Germany, where (EASDEC) The Singapore National Eye Centre 5th Inter- European professors will teach European The 12th meeting of the EASDEC will be held national Meeting will be held on 3–5 August residents. Further details: Priv Doz Dr Ulrich on 24–26 May 2002 in Udine, Italy. The dead- 2002 in Singapore. Further details: Ms Amy Schonherr, Friedrich-Alexander-University of line for abstracts is 15 February 2002. Three Lim, Organising Secretariat, Singapore Na- Erlangen-Nuemberg, Department of Ophthal- travel grants for young members (less than 35 tional Eye Centre, 11 Third Hospital Avenue, mology, Schwabachanlage 6 (Kopfklinikum), years of age at the time of the meeting) are Singapore 168751 (tel: (65) 322 8374;fax: (65) D-91054 Erlangen, Germany (tel: +49 9131 available. For information on the travel 227 7290; email: [email protected]). 853 4379; fax: +49 9131 853 4332; email: grants, please contact Pr CD Agardh, Presi- [email protected] dent of EASDEC, Malmö University Hospital, erlangen.de). SE-205 02 Malmö, Sweden (tel +46 40 33 10 CORRECTION 16; fax: +46 40 33 73 66; email: carl- XXIXth International Congress of [email protected]). Further de- We regret that an error occurred in the mailbox Opshthalmology tails: NORD EST CONGRESSI, Via Aquilea, letter published by Kenawy et al in the Novem- The XXIXth International Congress of Oph- 21.–33100 Undine, Italy (tel: +30 0432 21391; ber 2001 issue of BJO (2001;85:1394–5). The thalmology will be held on 21–25 April 2002 fax: +39 0432 50687; email: name of one of the authors was incorrect and in Sydney, Australia. Further details: Congress [email protected]) should have been Omar M Ayoub.
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