528 Ferguson, Kyle

abnormal vessels which form an integral part Recklinghausen's neurofibromatosis is unlikely of the lesion forming a 'haemangioneuro- to develop at this age. fibroma'. Such pathology could explain the pro-

1 Boltshauser B, Stocker H, Sailer H, Valavanis A. Intracranial Br J Ophthalmol: first published as 10.1136/bjo.77.8.528 on 1 August 1993. Downloaded from fuse bleeding encountered when excising this abnormalities associated with facial plexiform neurofibromas lesion. in neurofibromatosis type I. Neurofibromatosis 1989; 2: 274-7. 2 Porterfield JF. Orbital tumours in children: a report on 214 Malignant conversion to a sarcoma has been cases. Int Ophthalmol Clin 1%2; 2: 319-35. described in plexiform neurofibromas but these 3 Littlewood AH, Stilwell JH. The vascular features ofplexiform neurofibroma with some observations on the importance of have been in children with the other signs of pre-operative angiography and the value of pre-operative neurofibromatosis.4 Our patient will be reviewed intra-arterial embolisation. BrJ Plast Surg 1983; 36: 501-6. 4 Chaudhuri B, Ronan SG, Manaligod JR. Angiosarcoma arising indefinitely because the neurofibroma may in a plexiform neurofibroma: a case report. Cancer 1980; 46: recur, although the full syndrome of von 605-10.

BritishJournal ofOphthalmology 1993; 77: 528-529 Thelaziasis: report of two cases

T Shantikumar Singh, K Nareshkumar Singh

We report here two cases of thelaziasis, a rare findings were similar and comprised conjunc- parasitic of the eye in humans caused tival congestion, local oedema, and excessive by a spiruroid of the genus . lacrimation. No gross ulceration and follicles- Although the total number of cases in the world were seen; instead, there were whitish worms is not available 28 cases, 17 from Japan, seven seen moving in the conjunctiva across the from China, two from Korea, and one each from cornea. Routine examination of blood, urine, Russia and India, have been reported.'2 The and stool revealed no abnormal findings. Two complete life cycle of the nematode is not yet adult worms from each patient were removed fully understood; however, a snail is considered from the conjunctival sac after instillation of 4% lignocaine hydrochloride. The worms were later

to be a probable intermediate host.3 Burnett et al http://bjo.bmj.com/ found a species of Fania to be a naturally and identified as adult on the experimentally susceptible intermediate host for basis ofthe hexagonal mouth, absence ofalae and the larval development of Thelazia californiensis.4 cuticular ornamentations except for conspicuous A case of unilateral caused by the transverse striations near the anterior end which same species was described by Knierin and Jack are considered to aid movement across the and it was thought that a fly or gnat was the smooth surface of the cornea. The infection in both cases might have occurred from close possible mode of transmission in the Siskiou on September 24, 2021 by guest. Protected copyright. mountains of North California.s Generally, the association with infected dogs or through house clinical manifestations ofhuman thelaziasis com- ffies, Musca domestica. prised conjunctival congestion, pain, excessive lacrimation, and irritation. In Australia it is called 'bung' or 'blue eye' because of congestion and chemosis; there it is caused by Filaria Comment hebronema, another species of Thelazia.6 Diagnosis depended on the recognition of Permanent scarification and fibrous opacities of creamy white worms coiled in the conjunctival the conjunctiva and cornea may develop due to sac or migratory worms over the cornea. the presence and repeated movement of the Removal of the worms and morphological study worms. under a dissecting microscope were needed for Regional Medical species identification. Complete removal of the College, Manipur, India Department of worms with eye forceps provides a cure as no Microbiology Case reports drug is yet known to be effective against the T S Singh Two cases of thelaziasis have been seen in nematode. Because of the rarity of reports on Department of Manipur: an 18-month-old boy who presented human thelaziasis clinicians, apparently Ophthalmology with the complaints ofexcessive tears, irritation, unaware of the condition in which spiruroid K N Singh and redness of the left eye of 6 days' duration; nematode infestation can give rise to such a Correspondence to: and a 3-year-old boy who suffered from a blunt clinical manifestation, might think of other Dr T Shantikumar Singh, Department ofMicrobiology, injury to the left eye and presented with mild causes of the conjunctivitis. Thorough and care- NE Regional Medical College, pain, irritation, and conjunctival congestion of ful examination of the affected eye, bearing in Lamphelpat- 795 004, Manipur, India. 7 days' duration. On casual examination, the mind the possibility of such a condition, would Accepted for publication parents of both children had noticed thread-like justify the recognition ofmore cases and the right 7 April 1993 moving worms on the affected eye. Clinical treatment. Thelaziasis: reportoftzvo cases 529

1 Faust EC, Russel PF, Jung RC. In: Craig and Faust's clinical 4 Burnett HS, Parmelee WE, Lee RD, Wagner ED. Observa- parasitology. 8th ed. Philadelphia: Lea and Febiger, 1974: tions on the life cycle of Thelazia californiensis. J Parasitol 356-8. 1957; 43:433. 2 Yamaguchi T. A colour atlas of clinical parasitology. 1st Ed. 5 Knierin R, Jack MK. Conjunctivitis due to Thelazia London: WolfMedical, 1981: 170. californiensis. Arch Ophthalmol 1975; 93: 522-3. Br J Ophthalmol: first published as 10.1136/bjo.77.8.528 on 1 August 1993. Downloaded from 3 Duke-Elder S. System of ophthalmology. 2nd Ed. London: 6 Manson-Bahr PEC, Apted FIC. Manson's tropical diseases. 18th Kimpton, 1%5: 416-7. Ed. London: Bailliere Tindall, 1982: 604.

BritishJournal ofOphthalmology 1993; 77: 529-530

Sedation with nasal ketamine and midazolam for cryotherapy in retinopathy ofprematurity

Andre Louon, Joan Lithander, Venu Gopal Reddy, Anil Gupta

Sedation of infants in ophthalmology is a On admission to the operating theatre, the challenge for the anaesthetist. Often general baby was awake and not intubated. Monitoring anaesthesia is not required but a quiet and included electrocardiography, oxygen satura- immobile patient is necessary ifthe examination/ tion, aprecordial radio stethoscope, and tempera- treatment is to be successful. ture. Intravenousaccesswasavailable. An oxygen We report on a 44-day-old, 1-3 kg baby who tubing was positioned in front ofthe baby's nares was to receive cryotherapy treatment for retino- should oxygen be necessary. pathy of prematurity (ROP) and who was A mixture containing midazolam (5 mg/ml) succe$sfully sedated with nasal ketamine and 1-8 ml, ketamine (50 mg/ml) 1-6 ml, and normal midazolam. This simple and non-invasive saline 0 6 ml (total 4 ml) was prepared and a dose method might be of interest to the paediatric of 0'25 ml/kg body weight given, half of the ophthalmologist. More cases are required to required volume (0-4 ml) being instilled in each assess its safety and reliability. nostril. The total dose received was midazolam 0-9 mg and ketamine 8 mg. Within 4 minutes, the child was properly sedated (drowsy, motion- http://bjo.bmj.com/ Case report less, but not anaesthetised). This surviving twin baby girl was born at 26 After topical anaesthesia with amethocaine weeks of gestation with a birth weight of 770 g. chloride 1%, transconjunctival cryotherapy of In the neonatal intensive care unit, she had the avascular area in front of the ridge was bronchopulmonary dysplasia and suffered from performed with a broad tip in both eyes. respiratory distress syndrome, apnoea and During the whole 12 minute procedure, the bradycardic episodes, and septicaemia. pulse rate remained between 140 and 150 with on September 24, 2021 by guest. Protected copyright. She was intubated and ventilated for 33 days no episode of apnoea or bradycardia. Oxygen and required oxygen therapy sometimes at a saturation remained, without oxygen, in the fraction ofinspired oxygen of 1 0 for a total of44 range of 94% except on two 30 second occasions days. Episodes ofbradycardia occurred through- when it dropped to 90%. A short course of out. oxygen (1 1/min) increased it to 98%. Operating Ophthalmic check up revealed: right eye: Sultan Quaboos conditions were excellent for the ophthalmologist University Hospital, ROP grade 2 in zone II, left eye: ROP grade 3 in without any untoward movements. Muscat, Sultanate of zone II with plus disease (hyperaemia of the iris, The postoperative period in the special care Oman vasodilatation, and tortuosity ofthe vessels in the Department of baby unit was uneventful except for one brief Anaesthesia fundus). episode of bradycardia resolved by bag ventila- A Louon In view of this, cryotherapy was indicated. tion. V G Reddy The parents refused their consent for general Ophthalmic assessment at discharge, 6 weeks Department of anaesthesia but agreed to sedation. after treatment, showed significant regression Ophthalmology Preoperatively, apart from the ophthalmic with ROP grade 1 in zone III in both eyes. J Lithander problem, this baby had no neurological deficits, Department of was breathing spontaneously, and had normal Paediatrics behaviour for age. Comment A Gupta For the past 18 months, our department of Anaesthesia for short non-invasive ophthalmic Correspondence to: anaesthesia has used nasal ketamine and mida- procedures in small babies a Dr A Louon, Room 2781, poses problem to the Sultan Quaboos University zolam for paediatric sedation in computer tomo- anaesthesia and ophthalmology departments. Hospital, PO Box 32488 graphy with good results (Louon and Reddy If general anaesthesia is chosen, the baby will Al-Khod, Muscat, Sultanate of Oman. unpublished data, under review). We decided often be intubated. Because of limited space Accepted for publication that this technique could be used in this difficult while the ophthalmologist is working, a mask 17 March 1993 patient. cannot be applied, especially with low birth-