Abstract
Purpose :
To assess retinal sensitivity (RS) in extensive macular atrophy with pseudodrusen-like appearance (EMAP) using microperimetry (MP)
Methods :
Cross-sectional, observational study. 22 EMAP patients without pathogenic mutations for dystrophies and without macular neovascularization (44 eyes) and 12 healthy controls (24 eyes) underwent best-corrected visual acuity (BCVA), MP, fundus photography, optical coherence tomography (OCT) and blue autofluorescence (BAF).
A customized 20-stimuli grid was used to test mesopic (mRS) and dark-adapted scotopic (sRS) sensitivity in macular and paramacular areas. Fibrosis was evaluated on fundus photographs, while BAF images were analyzed for background autofluorescence of the posterior pole (iso- or hyper-autofluorescent) and to measure the size of macular atrophy. Foveal atrophy, vitreo-macular interface abnormalities, outer retinal tubulations, central sub-field thickness (CST) and sub-foveal choroidal thickness (SCT) were also investigated on OCT.
Results :
Mean age was similar for patients and controls (57.6±3.2 vs 57.3±2.1 years, p=0.77). BCVA was significantly lower in the EMAP group (60.1±21.0) compared with controls (85.0±0.0) (p<0.001).
RS turned out to be significantly reduced in EMAP patients both in macular and paramacular regions (all p<0.001). Lower mRS was significantly associated with foveal atrophy, fibrosis, hyper-autofluorescent background, larger atrophic areas and with lower BCVA, CST and SCT. Reduced sRS was instead associated with hyper-autofluorescent background, lower BCVA and with smaller CST and SCT.
On multivariate analysis, only fibrosis (p=0.04) and more extensive macular atrophy (p=0.02) were associated with reduced RS under mesopic conditions while no independent factor meaningfully affected scotopic RS in EMAP patients.
Conclusions :
Impaired dark adaptation and night blindness are frequent, burdensome symptoms arising in the early stages of EMAP.
Our study is the first functional assessment in EMAP using MP and provides evidence on the reduced macular function particularly under dark conditions. Our findings indicate that macular sensitivity significantly drops when signs of end-stage disease (e.g., fibrosis and extensive macular atrophy) appear. The absence of independent factors associated with sRS might be related to the presence of diffuse pseudodrusen-like deposits. This explains the significant visual impairment referred by this group of patients.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.