Crystalline retinopathy: evaluation of blood-retinal barrier by vitreous fluorophotometry

A 58-year-old man with typical crystalline retinopathy had started complaining of night blindness in both eyes at the age of 56 years. The visual acuity was 0.8 in the right eye and 0.7 in the left eye. Ophthalmoscopic examination showed crystal deposits scattered throughout the posterior pole of the fundus in both eyes. Electroretinogram showed subnormal amplitude and the light-peak/dark-trough ratio of the electrooculogram was reduced. Fluorescein angiography demonstrated atrophy of the pigment epithelium and partial loss of the choriocapillaris in the posterior pole. The crystal deposits were not stained with fluorescein. During the 3-year follow-up period, the crystal deposits coalesced, disappeared and reappeared at new places. Vitreous fluorophotometry was performed in both eyes of this patient. It was found that the rate of fluorescein penetration from the blood into the vitreous was markedly increased and the rate of the dye removal from the vitreous was greatly reduced, as compared to the results in normal subjects. Based on these clinical and fluorophotometric findings, it was concluded that the function of the blood-retinal barrier, particularly of the retinal pigment epithelium, was affected in this disease.