Abstract
Purpose :
We performed a retrospective, longitudinal, observational clinical study to analyze inner retinal changes in patients with geographic atrophy (GA) and identified potential morphological predictors for disease progression.
Methods :
One hundred eyes with GA (mean patient age ± SD: 79.2 ± 6.7 years) were assessed and compared to age-matched controls. Retinal layers on horizontal line scans through the fixation point, acquired with spectral-domain optical coherence tomography in tracking mode, were segmented manually (Figure 1, top). Zones of GA were defined based on choroidal signal enhancement from retinal pigment epithelium loss. An area of unaffected temporal retina was used as reference. The paired Student's t-test was used to compare atrophic areas with unaffected retina in the same eye and changes over time. Progression of GA was quantified on fundus autofluorescence images. Retinal layer changes were correlated with GA progression rate using Pearson correlation.
Results :
41 eyes with GA of 41 patients were included in the final analysis and compared to controls (n=16). The mean follow-up was 36.6 ± 18.6 months. Increased inner nuclear layer (INL) thickness was found in areas of GA (Figure 1, bottom left). INL thickness was inversely correlated with best-corrected visual acuity. Moreover, INL thickness in areas adjacent to GA was associated with progression rates (Pearson r = 0.48, Figure 2).
Conclusions :
Findings demonstrate that atrophy of the retinal pigment epithelium-photoreceptor complex in GA is associated with INL thickening. We speculate that this layer thickness increase is caused by reactive Müller cell changes and dysfunction. INL thickness in the retina adjacent to areas affected by GA was associated with atrophy progression rates.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.