Sequential structural and functional change in geographic atrophy on multimodal imaging in non-exudative age-related macular degeneration.

PURPOSE

To investigate the temporal order of photoreceptor atrophy, retinal pigment epithelium (RPE) atrophy and visual acuity loss in patients with center-involving geographic atrophy (GA) in non-exudative age-related macular degeneration (neAMD).

METHODS

Forty eyes of 25 consecutive patients who eventually developed center-involving GA were investigated. Fundus autofluorescence (FAF) and infrared image coupled optical coherence tomography (OCT) were acquired at each visit. Development of RPE atrophy and photoreceptor atrophy was defined as abnormal hyper/hypo-fluorescence on FAF and photoreceptor loss on OCT over 50% of the vertical or horizontal diameters of the center 1 mm circle, respectively. Visual acuity loss was defined as worsening of more than 0.2 logMAR compared to baseline. Kaplan-Meier analyses was performed to compare the sequential order of these three events.

RESULTS

Mean age was 72.72 ± 8.63 years, and follow-up duration was 27.36 ± 17.22 months, with an average number of visits of 3.04 ± 1.54 during follow-up. GA progressed from photoreceptor atrophy on OCT, RPE atrophy on FAF, and then to vision loss (p < 0.001). The median survival time of photoreceptors preceded that of visual acuity by 16.3 months, and the median survival time of RPE preceded that of visual acuity by 7.0 months. At baseline, majority of eyes showed drusen only (57.5%), while the most common feature was incomplete RPE and outer retinal atrophy at 3-year follow-up (40.4%).

CONCLUSION

In the progression of center-involving GA, photoreceptor atrophy on OCT and RPE atrophy on FAF precedes visual decline, and can act as biomarkers predicting future visual decline within the following years.