[Fish eye disease]

Area of Science:

• Ophthalmology
• Medical Genetics
• Biochemistry

Background:

• Fish eye disease is a rare autosomal recessive disorder characterized by corneal opacity and reduced high-density lipoprotein (HDL) cholesterol.
• It results from mutations in the lecithin-cholesterol-acyltransferase (LCAT) gene, leading to impaired cholesterol metabolism.
• Patients typically present with progressive corneal clouding and impaired vision, often without other systemic complications like premature atherosclerosis.

Observation:

• A 67-year-old man presented with several months of impaired night vision and progressively cloudy corneas over 20 years.
• He had a history of arcus senilis since age 21 and a family history suggestive of similar eye changes.
• Ophthalmological examination revealed marked corneal dystrophy, with normal general physical examination and normal total cholesterol and triglyceride levels.

Findings:

• Serum analysis revealed significantly reduced high-density lipoprotein (HDL) cholesterol (8 mg/dl).
• Within the HDL fraction, concentrations of triglyceride, phospholipids, and cholesterol esters were decreased.
• Cholesterol-esterification rate and HDL-associated lecithin-cholesterol-acetyltransferase (LCAT) activity were markedly reduced, indicating impaired LCAT function.

Implications:

• The clinical presentation and biochemical findings are characteristic of fish eye disease.
• This case underscores the importance of assessing HDL cholesterol and LCAT activity in patients with unexplained corneal opacities and visual disturbances.
• Early diagnosis and management can potentially mitigate visual impairment and guide genetic counseling.