Corneoretinal dystrophy (Bietti)-- Long-term course of one patient over a period of 30 years, and interindividual variability of clinical and electrophysiological findings in two patients

Abstract

A tapetoretinal dystrophy with crystalline deposits of the retina and limbal cornea was described by Bietti in 1937. To date, only a few cases with long-term follow up have been reported. Two patients are presented including the clinical findings, fluorescein angiography, electrophysiology [electroretinography (ERG); electrooculography (EOG), multifocal electroretinography (MERG)], adaptometry, and transmission electron microscopy (TEM) of peripheral blood lymphocytes. The clinical findings were at least in part documented over a period of 30 years. The most striking features were deposits in the retina and cornea associated with crystalloid lysosomal inclusions in peripheral lymphocytes, and choroidal atrophy especially in advanced stages of the disease. The light rise (EOG), rod- and cone-driven responses (ERG), the responses of the MERG and visual fields were affected progressively during the course. These advanced changes of the retinal pigment epithelium and choriocapillaris were observed in the 2(nd) decade already. The findings of deposits in the cornea, retina and lymphocytes may help to differentiate BCD from other chorioretinal dystrophies. The results confirm a variable course in clinical expression of BCD between individuals.