Bietti with Outer Retinal Tubulations – Page 19 of 24

Comments

• Bietti crystalline corneoretinal dystrophy (BCD) is an autosomal recessive retinal dystrophy first described by Bietti in 1937.³
• Numerous tiny glistening yellow-white crystals in the posterior pole with RPE atrophy and hypertrophy along with choroidal sclerosis characterize the disorder.²
• About half the cases have similar crystals in the superficial peripheral cornea.⁴
• The disorder has pigmentary clumping in the retina similar to RP and similar ERG and field findings.⁵
• BCD is caused by a mutation in the novel gene CYP4V2.^6,7,8,9
• The crystals appear to be cholesterol or cholesterol ester and complex lipid in nature⁵ but not obviously associated with metabolic disease.¹⁰
• FORTs (Freund’s Outer Retinal Tubulations) appear to be present in some but not all retinal degenerations.¹
• Both the etiology and significance of FORTs are unknown at present.