Case report The incidence of penetrating injury is thought in part to be due to globe shape, with myopic eyes being at A 64-year-old woman presented to eye casualty with a greater risk. Vohra and Good7 suggest, however, that a second episode of right dacryocystitis. The visual acuity medial canthal approach is the safest, especially in larger was 6/6 bilaterally. She was given a 7 day course of oral globes? This is because of a reduction in the equatorial amoxicillin 500 mg t.d.s. with flucloxacillin 250 mg q.d.s. width to axial length ratio in high degrees of axial and was reviewed when the infection had settled. myopia. Inflammation of the tissues surrounding the Syringing showed patent canaliculi with regurgitation usual landmarks, for example following dacryocystitis, and she was listed for dacryocystorhinostomy (DCR) as in this patient, can alter the anatomy of the injection under local anaesthesia. site and increase the risk of perforation. MeyerS reports In the anaesthetic room the patient was sedated with some success with topical anaesthetic techniques which 2.5 mg of intravenous midazolam. Two drops of would eliminate the risk of penetrating ocular injury. amethocaine were instilled into both eyes. Two puffs of Early diagnosis and treatment of ocular perforations 2% lignocaine spray were applied to the right nasal are essential for a good visual outcome6,9 and therefore passage. A nasal pack of 5% cocaine with adrenaline was there should be a high index of suspicion in those cases placed in the right nasal antrum. A local anaesthetic where the injections are excessively painful, or mixture containing 4 ml of 2% lignocaine with 1:200 000 ineffective, or if there is hypotony of the globe or a adrenaline and 4 ml of 0.75% bupivacaine was decrease in visual acuity. DCR surgery has been administered to three sites using a 25 mm, 25 G needle in effectively performed under local anaesthesia for many a standard fashion.2 The infraorbital nerve was years4 but care must always be taken during intraconal infiltrated with 3 ml of anaesthetic, the skin of the side of anaesthetic injections. the nose with 2 ml, and 3 ml was injected medially, lateral to the caruncle with a peribulbar technique. The References patient experienced some discomfort during the 1. Duker IS, Belmont JB, Benson WE, et al. Inadvertent globe administration of the anaesthetic, but this was mild. perforation during retrobulbar and peribulbar anaesthesia: However, once the initial skin incision was made, the patient characteristics, surgical management, and visual patient complained of pain that was not relieved by outcome. Ophthalmology 1991;98:519-26. further infiltration of anaesthetic to the skin and 2. Hurwitz JJ. The lacrimal system. Philadelphia: Lipincott­ Raven, 1996:257-9. periosteum. It was necessary to convert to a general 3. Benger R. Day-surgery external dacryocystorhinostomy. Aust anaesthetic, and the operation was completed without N Z J OphthalmoI 1992;20:243-5. further incident. 4. Dresner SC, Klussman KG, Meyer DR, Linberg JV. Outpatient The following day she was noted to have a mid­ dacryocystorhinostomy. Ophthalmic Surg 1991;22:222--4. 5. McCombe M, Heriot W. Penetrating ocular injury following dilated pupil on the right, with a corrected visual acuity local anaesthesia. Aust N Z J Ophthalmol 1995;23:33-6. of 6/9. Fundoscopy showed a raised appearance of the 6. Gillow JT, Aggarwal RK, Kirkby GR. Ocular perforation temporal and inferior retina and choroid, the macula and during peribulbar anaesthesia. Eye 1996;10:533-6. disc were normal and there were no retinal 7. Vohra SB, Good PA. Altered globe dimensions of axial haemorrhages. The possibility of globe perforation was myopia as risk factors for penetrating ocular injury during peribulbar anaesthesia. Br J Anaes 2000;85:242-5. raised at this point. One week later there had been a 8. Meyer DR. Comparison of oxymetazoline and lidocaine deterioration in the visual acuity to 6/36 and there was versus cocaine for outpatient dacryocystorhinostomy. vitreous haemorrhage with a nasal suprachoroidal Ophthalmic Plast Reconstr Surg 2000;16:201-5. haemorrhage. The suprachoroidal haemorrhage resolved 9. Puri P, Verma D, Mckibben M. Management of ocular over the next week and at this stage retinal haemorrhages perforations resulting from peribulbar anaesthesia. Indian J Ophthalmol 1999;47:181-3. with scarring and vitreous incarceration were seen two disc diameters nasal to the optic disc. This was felt to J.P. Kersey Sleep represent a needle track from a perforating injury and T. PRo Hodgkins she was admitted for vitrectomy and endolaser to the Southampton Eye Unit area of injury. Post-operatively, the retina remained flat Southampton, UK and she achieved a final visual acuity of 6/9. Mr P.R. Hodgkins � Southampton Eye Unit Southampton S016 6YD, UK Comment During the last 10 years DCR surgery has increasingly been performed under local anaesthesia3,4 because of the Sir, benefits of this technique to patient health and the move towards outpatient surgery. The local anaesthetic Rapid development of visual field defects associated technique usually involves a medial canthal peribulbar with vigabatrin therapy injection.2 Ocular perforation is a recognised Vigabatrin, a selective irreversible gamma-aminobutyric complication of retrobulbar and peribulbar anaesthesia acid (GABA) aminotransferase inhibitor, is a new for cataract surgeryl,5,6 but has not been reported during antiepileptic drug that is generally well tolerated with anaesthesia for DCR. few side-effects. However, bilateral permanent visual 672 I'tG.l,...£ FIIiLD AUQLVSIS £VEl IUCHT 1'''At "'(\.0 'WAYeI. ""'. un 10. "5-4" 008 ••,- al IDI .,.... .. 1!M1] eo oc:. ••1 '-1S41! "'-"-.' ...... '"1 f)l-:".�lQrlf·",*", 11 ..,UI.loIl. "' ....m ',.,. ... 11- 1:"- .� .....' n'till'. ·:4':;."1tQ'T1 "'­ �'1S_I'" -""'" r._ tJ'iN I!II' �'I f.' '.n­ I:C·�· .:uI1' 1'. 1lJI1m1�r..: ... ... .... 1=-,r.�11 •• .. 'U ... �.U . ,... .. 'r..s.H. 1lJ'I_,.·UIo'J I.' U til 1 nJI 0, ,J. dl 111 It 11 I h ,. II , t � i " ill I'L IlL .u It� 8 J:J D 8 I t Iff, IlL � . """. ,B..,.I!. , ,\ .. ,IL It It (it It • � .Jt · · .g,· · ... · ,t,,� ". • • ......!..-.tH, " �" It ,8J l it · IlL t� , 1) ,BI tIL D • t9J " " It I I) ,H, nil",. , 11 n .'1. ,I!, .�. " ,Ii. .B. ...au,UI,H. .u. " .IL ,I!. n ,U, I L I � -t '13 -1 11 ... 1I' -t ., ''''1 ., ., ., -71 ...·) • ., '11" .. .. • )t IfI -l -1 1" '1 U .,., 04 1 •• 1 t ,-I """,11 I I I ., ...... 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Most recent automated 30-2 visual field test results showing symmetric binasal field defects: (a) right eye, (b) left eye. field defects in association with the use of vigabatrin vigabatrin intake. Because no visual field testing was l consistently continue to be reported. �3 We describe a performed before the introduction of vigabatrin in our woman who started to experience visual abnormalities patient, we presume that this drug is the most likely including field defects as early as 6 months following cause of the later documented visual field changes. ...... _.GMT T..ra1E INate· a. ·VCLLOY .... , .. PI, ................ "" "'�"I"'.ITI m-.d' �, .... ....... '1"""" 100.:,.., a::a k�' ".,. _II., ......... Pall, ..... ......... 4.1. ""'" ..aI, tn.. � CUll '",,1,. tell u..- � II'lUI -""'" "'11" IIMIU" · ..'NIf .... ... .1111.... ).0 ...1.1. ...,1'111&1 ..... , '''.N(fIIIIt'" ' ... , ........ , IU'--.... � -- 11'1:1.'" '. ., , II II I, ,U, I ., j, ., . ., I I _) J I' ,H. U , .:r. ,:I I ,L 'I n ,:(.. :t ' " IlL ,IL ,�L ,a. .. u __ " w .. ·n • ·iHH�-4--!-�III�:�-!I .. y �i��lt��j-,,--+--}�al-';I ' " , Jt '" ItL II II -, .IL I' IlL J .al ., " ,UI I�' � II 1 ., .lI, U II ,:L I ,:L " I II ,:� 'I .1 " l n I I ,:L n ,11 .•al ,a, , L "II ,al 'I ,If U ., ,:I. ' • 'o�I.�I."�nu .·� •• t."I.a... n . Il1U'Ch JI. WI • .,uoa••• ... 'I'! , (a) (b) Fig. 2. The 60-4 blue-an-yellow perimetry results demonstrate bilateral dense annular scotomas: (a) right eye, (b) left eye. 673 Case report changes first started. The patient reported here demonstrates that visual field loss may occur soon after A 60-year-old otherwise healthy woman has been treated the institution of vigabatrin therapy. for epilepsy for 10 years. The first drug she was prescribed was carbamazepine, and 2 years ago vigabatrin was added at a dose of 500 mg q.i.d. A year References later sodium valproate was also added. Six months after 1. Lawden MC, Eke T, Degg C, Harding GFA, Wild JM. Visual she started vigabatrin she developed photophobia, field defects associated with vigabatrin therapy. J Neural flickering lights and saw 'shadows at both sides'. On Neurosurg Psychiatry 1999;67:716-22. 2. Manuchehri K, Goodman S, Siviter L, Nightingale S. A ocular examination her visual acuity was 20/20 both controlled study of vigabatrin and visual abnormalities.