Abstract
Purpose :
Inherited retinal degenerations (IRD) represent the commonest cause of blindness in the working age population. While disease-modifying treatments are emerging, the modifiable features of IRD merit treatment at an early stage. Herein we report the prevalence of acquired features & extraretinal genotype-phenotype correlations in a genotyped Irish IRD cohort.
Methods :
Patients enrolled in the Irish National IRD program (Target 5000) were included in this retrospective analysis, approved by ethics committee of Mater Hospitals Dublin Ireland. Patients were assessed for acquired features of IRD by phenotype (retinitis pigmentosa, RP; cone dystrophy, COD; macular dystrophy, MD; choroidal; Leber Congenital Amaurosis, LCA; Congenital Stationary Night Blindness, CSNB & vitreoretinopathy) & genotype groups. Prevalence of refractive error, cataract, cystoid macular lesions (CML), epiretinal membrane (ERM), retinal detachment (RD) & keratoconus were calculated.
Results :
518 patients enrolled mean age 40.2±19.7y, & 54% male. 72% had a confirmed genotype. Median VA was LogMAR 0.48 (IQR0.82), best in vitreoretinopathies (0.18 IQR0.33) & worst in LCA (1.78 IQR 2). Cataract (46% of eyes) was greatest in Usher syndrome (83% esp. USH2A 100%) & least in CSNB (13%). CML (14%) were most common in X-linked retinoschisis (XLRS 73%) AD RP (35% esp. RHO 54%) & least in XL RP (4%). ERM (13%) was greatest in Bardet-Biedl Syndrome (56%) & least in CSNB/LCA (7% each). Highest myopia was found in XL RP (-5.58±4.4D incl. RPGR carriers -4.89±2.37), CSNB (-7.86±5.21D) & vitreoretinopathy (-6.71±5.88D) & hyperopia in MFRP (+12.38±4.15D) & XLRS (+4.41±2.68). RD (6%) was predominantly (71%) in the vitreoretinopathy group. Keratoconus was seen in 1% overall, but 12% of LCA, a nearly pathognomonic feature. 22% had amblyopia, due to multiple visual pathologies disrupting early visual development.
Conclusions :
Though individually rare, collectively IRD are a major management challenge. Characteristic retinal & extraretinal features may facilitate diagnosis & management. While disease-modifying treatments are slowly coming, acquired features are common & modifiable. Proactive management of these features may limit amblyopia & maximize visual function. Also, these characteristics may allow more accurate rationalization of uncertain genetic findings, facilitating access to novel gene-specific treatments when available.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.