Prevalence of macular abnormalities assessed by Optical Coherence Tomography in patients with Usher Syndrome

Abstract

Purpose : We performed a retrospective observational clinical study of macular abnormalities in Usher Syndrome (USH) investigated by Optical Coherence Tomography (OCT) and the relation with clinical findings.

Methods : A retrospective study was performed reviewing medical records and OCT of 215 patients (46 USH1 aged 30.4 ± 14.7 yrs, 169 USH2 aged 38.2 ± 15.2 yrs; 107F). Patients with diabetes, ocular inflammatory diseases, primary retinal vascular diseases, severe cataract or vitreous opacities were excluded. OCT (Zeiss SD-OCT) was performed using a 5 line raster and a macular cube scan. Measures were expressed as means ± SD and categorical variables as counts and percentages. Logistic regression was used to investigate the relation between macular abnormalities and other covariates. Linear regression models were adjusted for factors influencing Best Corrected Visual Acuity (BCVA). The study was carried out in compliance with the Declaration of Helsinki and approved by local Ethic Committee.

Results : Macular abnormalities were found in 208 (48.4%) out of 430 eyes. The most frequent was cystoid macular edema (CME, 16.3%), followed by epiretinal membrane (ERM, 14.4%), vitreomacular traction (VMT, 14%) and lamellar macular hole (LMH, 3%); full thickness MH (FTMH) was found in 3 eyes (0.7%). CME was significantly associated with younger age and cataract (p=0.002), whereas VTM and FTMH were age-related (p<0.05). According to USH subtype, macular abnormalities were found in 52 eyes of USH1 patients (56.5%) and in 156 eyes of USH2 patients (46.2%). CME was more frequent in USH1 (30.4% vs 16.9%), as well as VMT (23.9% vs 16%), while ERM and MH were more frequent in USH2. All abnormalities were more frequent in males, except FTMH, having the same distribution. According to lens status, CME and ERM were more frequent in eyes with cataract, whereas VMT and FTMH in pseudophakic eyes. No significant association was found between BCVA and CME, VMT and ERM, while there was a significant correlation between BCVA, FTMH (p<0.001) and LMH (p=0.019).

Conclusions : Macular abnormalities are more frequent in USH patients than general population, showing a distribution similar to non-syndromic RP, with the exception of VMT having a higher frequency in USH. CME is the most common alteration, followed by ERM. Screening by OCT is recommended for the early detection and treatment of macular disorders associated to RP.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.