Abstract
Purpose :
To investigate the prevalence, visual significance, and genotype-phenotype associations of foveal hypoplasia (FH) in inherited retinal degenerations (IRDs).
Methods :
In this retrospective case-control study, the case group of 285 patients (492 eyes) consisted of genetically-confirmed IRDs while the control group contained 256 IRD-free patients (444 eyes). Exclusion criteria were age less than four, poor-quality/absent optical coherence tomography (OCT), or loss of retinal OCT lamination. LogMAR Best corrected visual acuity (BCVA), OCT, and demographic data were obtained. Published FH grading was used.
Results :
Foveal hypoplasia was significantly prevalent in retinitis pigmentosa (RP; 110/351, 31.33%, p<0.001), as well as IRDs overall (135/492, 27.44%, p<0.001), compared to controls (20/444, 4.50%). In RP, LogMAR BCVA in FH grade 1 (0.18) was not different from age and gender matched patients with fully-developed fovea (0.18) (p=0.06). Similarly, in controls BCVA of FH grade 1 (-0.01) was not different from age/gender-matched eyes with fully-developed fovea (0.02) (p=0.06). RPGR (21/50, 42%) and USH2A (16/75, 21.33%) were significantly associated with FH compared to controls (p<0.001, p<0.001).
Conclusions :
FH is associated with IRDs, and RP in particular. Genotypes RPGR and USH2A are each individually associated with FH. Although grade 1 FH is associated with IRDs that may reduce visual function, grade 1 FH is not associated with reduced visual acuity within the IRD cohort, indicating visual insignificance of persistent inner retinal layers. The presence of grade 1 or atypical grade FH in a patient with reduced vision should prompt consideration of an IRD diagnosis.
This is a 2021 ARVO Annual Meeting abstract.