Diffuse corneal haze: a rare presentation of fish-eye disease

Fish-eye disease (FED) is a rare, autosomal recessive genetic disorder that can present at any age, from as early as the second decade of life to late adulthood. The hallmark clinical manifestation of FED is dyslipidemia and slowly progressive bilateral corneal opacification, which can impair vision quality due to highly elevated straylight. Here, we report the ophthalmic findings observed in FED by presenting a case that had been misdiagnosed for years until genetic testing was performed.

Case report.

A 50-year-old patient presented with a 30-year history of subnormalvision, which had progressively worsened over the past two years, accompanied by intermittent episodes of bilateral ocular dryness. Ophthalmic examination revealed diffuse corneal haze despiterelatively well-preserved visual acuity. Anterior segment-opticalcoherence tomography (AS-OCT) imaging showed multiple areas of hyperreflective opacities bilaterally throughout the corneal stroma. A lipid panel revealed very low plasma high-density lipoproteincholesterol (HDL-C) levels. Subsequent genetic testing provided an explanation, identifying two novel variants in the LCAT gene, c.840_862dup, p.(Val288Alafs *130) and c.115A > T, p(Lys39*).

Ultimately, FED should be considered in the differential diagnosis of corneal clouding combined with low plasma HDL-C, which can be investigated using AS-OCT and confirmed through genetic interrogation of the LCAT gene.