Letters to the Editor

Vogt Koyanagi Harada disease T o the Editor: Wakefield, McCluskey and Reece have described three cases ofvogt Koyanagi Harada disease,' which they state has not been previously reported in the Australian literature. In 1950 I reported two Victorian cases in detail' with the investigations considered appropriate at that time. When the disease burnt out they were both legally blind. Ronald Lowe MD, FRACO 82 Collins Street Melbourne 3000

References 1. Wakefield D, McCluskey P, Reece G. Cyclosporin therapy in Vogt Koyanagi Harada disease. Aust NZ J Ophthalmol 1990;18: 137-142. 2. Lowe RF. Harada's disease: Bilateral uveitis with poliosis, vitiligo alopecia and dysacousia (The Vogt Koyanagi syndrome). Trans Ophthalmol SOC Aust 1950;lO: 11-21.

Viscous cyclopentolate T o the Editor: A clinical trial was undertaken to compare the cycloplegic effects of two different formulations of cyclopentolate 1% eye drops in 15 children by measuring residual accommodation amplitudes. A single drop of viscous cyclopentolate was as effective as two drops of commercially available aqueous solution and offered the advantages of patient acceptance, comfort and safety compared to multiple instillations. Cycloplegic eye drops are essential for accurate assessment of refractive status and fundi in children and young adults. T h e use of eye drops and bright lights are the common sources of discomfort in most paediatric examinations, and often lead to distress, loss of cooperation and inadequate assessment. Multiple instillations of cycloplegic agents result in increased ocular and nasal absorption and a higher risk of systemic toxicity. Repeat doses or Letter to the Editor

stronger solutions are often necessary in subjects with dark irides. Viscous cycloplegics have been advocated by A. Jampolsky (personal communication) but have not been compared to the usual agents in a published clinical trial. Commercially available cyclopentolate 1% was used as the aqueous solution. T h e viscous solution was prepared by mixing equal volumes of cyclopentolate 2% and methylcellulose 2% to yield a 1% solution. Fifteen healthy subjects in whom accommodation could be measured ranged in age from five to 13 years. Each subject randomly received 2 drops of aqueous solution in one eye and a single drop of viscous solution in the fellow eye. The two aqueous drops were given five minues apart. A separate observer used an RAF rule to measure the initial and then residual accommodation amplitudes in 437

each eye at five, 15 and 30 minutes after the first drops had been instilled. Seven patients had light irides and eight had dark irides. Eleven of the 15 had no measurable residual accommodation in either eye at 30 minutes indicating that both agents were effective cycloplegics in this sample. T h e remaining four subjects with some residual accommodation had dark irides. T h e two test agents showed similar rates of onset and degree of cycloplegia by 15 minutes. Pupil sizes were not significantly different between the two eyes and all pupils were well dilated and non-reactive at 30 minutes. During retinoscopy there did not appear to be any manifest accommodation. There were no signs of systemic toxicity. T h e thicker solution appeared to the observer to cause less discomfort for each subject and five subjects confirmed this verbally while six subjects felt that both agents were equally uncomfortable. Any measure that allays anxiety and distress is a great advantage in paediatric ophthalmic examinations. A single instillation of a viscous cycloplegic should enhance ocular absorption and improve cooperation for that examination. It may reduce the negative conditioning effect of eye drops so often observed in young children attending eye clinic

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reviews and receiving multiple drops at each visit. T h e viscous solution does not appear to be blinked out or washed out as readily, yet does not interfere with the quality of retinoscopy reflexes or subjective refraction. In theory there should be a slower or reduced nasal absorption of the viscous preparation, thus making it a safer choice in babies and for those at increased risk of systemic toxicity. A second drop of the viscous agent should be considered for darkeyed subjects. T h e study found that a single drop of viscous cyclopentolate 1% was as effective as 2 drops ofthe commercially available solution. If only one drop of cycloplegic is to be used in each eye the viscous agent should be more effective and may be safer and more comfortable in children. Ross Miller FRACO, FRACS Formerly Staff Specialist T h e Children’s Hospital Camperdown NSW 2050 Epping NSW 2121 Cathie Searle, DipAppSci, DOBA Orthoptist The Children’s Hospital Camperdown NSW 2050

Australian and New Zealand Journal of Ophthalmology 1990; 18(4)

Viscous cyclopentolate.

Letters to the Editor Vogt Koyanagi Harada disease T o the Editor: Wakefield, McCluskey and Reece have described three cases ofvogt Koyanagi Harada d...
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