Bietti's crystalline dystrophy in Asians: clinical, angiographic and electrophysiological characteristics.

This article describes nine Chinese patients with Bietti's crystalline dystrophy, including two families, one consisting of three siblings and the other a pair of sisters. All patients had the classic refractile deposits located in all layers of the retina, with varying degrees of pigment epithelium atrophy. However, paralimbal crystals were not seen in the anterior corneal stroma. We describe clinical, angiographical and electrophysiological characteristics, and also review the literature on Bietti's crystalline dystrophy. All patients had full eye examination, including best corrected visual acuity, biomicroscopy, applanation tonometry and dilated funduscopy. Fluorescein angiography and indocyanine green angiography were performed, together with visual fields and electrophysiologic studies. All nine of our patients were phenotypically heterogeneous, with varying age and symptoms at presentation, as well as different degrees of progression. Age was not found to be a predictor of severity. The differences in disease severity, even within sibling groups, suggested that perhaps other factors were at play in phenotypic expression. We found that in early ICGA, all stages of BCD had delayed choroidal filling, which has not been previously described. We also observed a relative derangement of inner choroidal circulation as evidenced by late hypofluorescence on the ICGA. However, it is as yet unclear whether this circulatory disturbance is due to primary involvement of the posterior ciliary arteries, or secondary to choroidal and/or retinal pigment epithelial atrophy. While the FA and ICGA findings were similar, we found that the true extent of the atrophic areas was better delineated by ICGA. ICGA was also superior in outlining the degree and extent of choroidal vascular compromise.

An unusual case of post-cochlear implant performance degradation in a patient with suspected Cogan's syndrome.

Cogan's Syndrome is an autoimmune disorder that can affect the ear, eye and other organs. Although rare, Cogan's Syndrome is particularly relevant to the cochlear implant surgeon because the resulting hearing loss is often bilateral and the majority of cases progresses to profound levels where cochlear implantation may be indicated. There are many issues relating to this condition that concern the cochlear implant surgeon. Its rarity, lack of specific laboratory diagnostic tests and variability in the onset and types of manifestation relating to the ear, eye and other organs often pose diagnostic difficulties. Pre-operatively, the cochlear implant surgeon must anticipate and exclude the possibility of cochlear luminal obliteration and ossification. Although the post-implant hearing results are expected to be generally good in Cogan's Syndrome, the possibility of adverse hearing outcomes cannot be ruled out whether in the initial or subsequent post-operative period. The possible side effects of long-term immuno-suppressive therapy on the well-being of the cochlear implant are to be appreciated and managed. A case which posed much difficulty in management is presented and discussed to highlight some of these challenges.