15/04/2023
FEVR in a 45 yrs old female patient with right eye presenting with extensive peripapillary lipid deposition & exudation with thick ERM over macular region ( I & II image ) followed by straightening of vessels with macular drag and scar in left eye (III image) & 4th image post surgical day 7.
Exudative vitreoretinopathy Type I or commonly known as familial exudative vitreoretinopathy (FEVR)
A hereditary retinal disorder with features similar to retinopathy of prematurity (ROP); though patients lack history of prematurity or oxygen supplementation.
Clinical presentation:
➡️Peripheral retinal vascular abnormalities i.e Telangiectasia, Aneurysms, Arteriovenous shunts, non-perfusion & ischaemia.
➡️Dragging & straightening of posterior retinal vasculature into periphery
➡️Peripheral sub-retinal & intraretinal exudation with lipid deposition
➡️High risk of Tractional retinal detachment due to fibrovascular prolifera-
tion
FEVR is a genetically heterogeneous disorder that is most commonly autosomal dominant & less commonly autosomal recessive or X-linked recessive.
➡️Approximately 50% of cases are linked to mutations in one of four genes: FZD4, LRP5, TSPAN12, and NDP. FZD4 (AD), LRP5 (AR and AD) & TSPANI2 (AD) located on chromosome 11 while NDP, the same gene responsible for Norrie Disease, is located on the X chromosome.
➡️LRP5 & ND mutations have systemic implications:
➡️LRP5 mutations linked to decreased bone mineral density
➡️NDP mutations
may be linked to deafness
FEVR exhibits marked variability in penetrance & family history of known FEVR or unexplained visual loss is commonly absent.
Screening of all family members with widefield angiography frequently identifies other affected individuals who may require close ophthalmologic follow-up or systemic intervention.
Management 💊:
➡️Patients with peripheral retinal ischemia & neovascularization may benefit from prophylactic panretinal laser photocoagulation
➡️Surgical intervention is needed for exuberant epiretinal membrane or vision threatening tractional retinal detachment
➡️ Systemic intervention is indicated with LRP5 subtype, by managing low bone density
