Retinitis pigmentosa and Coats's disease.

The association of two rare ocular conditions of unknown aetiology presents the clinician with an opportunity to study interrelating factors. The association of retinitis pigmentosa with Coats's disease has been previously reported in three patients (Zamorani, I956; Morgan and Crawford, I968), in all of whom bilateral involvement occurred with severe visual loss. The present case which has been fully documented demonstrates the association of bilateral retinitis pigmentosa with retinal telangiectasia (Coats's disease) and drusen of the optic disc. Case report A I5-year-old girl was seen at the Medical Ophthal-mology Unit in July I973 with a Io-year history of impaired vision and recent further deterioration. HISTORY The patient's birth had been normal although two weeks premature and her early development had also been normal. At the age of five years she was found to be deaf in her right ear and her parents also noticed she had poor vision in dim light. In July I970 at the age of 12 years she was admitted to the Medical Ophthalmology Unit. Visual acuity was 5/60 and N8 in the right eye and 6/i8 and N8 in the left; colour vision was reduced in both eyes. Peripheral visual fields were markedly constricted. Fundus examination showed exposed drusen of the right disc and buried drusen of the left, and a widespread pigment epithelial disturbance with a few clumps of intraretinal pigment deposition. The choroidal vessels were visible and a serous detachment was present inferiorly in the right eye. There was no family history of retinitis pigmentosa or consanguinity although electrodiagnostic tests performed on her two younger sisters showed a slightly subnormal light rise in the electro-oculogram (light rise right eye 228 per cent, left eye 2IO per cent in the I2-year-old sister; right eye 243 per cent, left eye 200 per cent in the io-year-old sister). In July 1973 the visual acuity in the right eye was 5,6o and N8 and in the left 6/6o and N8 with correction. The peripheral visual fields showed marked constriction to 5' from fixation on each side, and the central fields showed severe loss of visual function including severely diminished macular thresholds (Friedmann analyser). Fundus examination showed exposed drusen of the right optic disc and widespread degeneration of the retina and pigment epithelium including the macular region. There were bilateral inferior serous detachments with dilated and tortuous retinal vessels. Fluorescein angiography (Fig. i) demonstrated good filling of the retinal …