Purpose
To analyze, on a long term basis, choroidal thickness changes in patients with geographic atrophy (GA) secondary to age-related macular degeneration, with or without choroidal neovascularization (CNV) in the fellow eye.
Methods
In this prospective study, nineteen consecutive patients (27 eyes) affected by GA at least in one eye were enrolled. All eyes were studied, every 6 months, by means of: enhanced depth imaging spectral-domain optical coherence tomography to measure choroidal thickness; microperimetry to assess retinal sensitivity; blue (B-FAF) and near infrared-wavelenght fundus autofluorescence (NIR-FAF) to measure GA enlargement rate. Patients were divided in two groups: patients with bilateral GA (8 patients; 16 eyes) without evidence of CNV (bilateral GA group) along the study; patients with GA in one eye and CNV or disciform scar in the fellow eye (11 patients, fellow eye CNV group). In the fellow eye CNV group, CNV was present at baseline or developed during follow-up.
Results
Mean follow-up was 1.6 ± 0.76 years, without difference between the two study groups (p=0.6766). Choroid was significantly thicker in the bilateral GA group eyes compared to the fellow eye CNV group eyes at baseline (mean choroidal thickness: 170.5 ± 78.5 μm vs 129.1 ± 36.1 μm, p = 0.0371 ) and during follow-up (mean choroidal thickness: 173.2 ± 86.1 μm vs 123 ± 32.1 μm, p = 0.0340) . Mean choroidal thickness significantly decreased during follow-up only in the fellow eye CNV group (p=0.0276 in the fellow eye CNV group vs p= 0.4137 in the bilateral GA group). Mean GA area was not significantly different in the two groups neither at baseline nor at follow-up (p=0.4118 in B-FAF and p= 0.6806 in NIR-FAF at baseline, p= 0.5734 in B-FAF and p=0.8945 in NIR-FAF at follow-up) even if mean GA area significantly increased in both groups during follow-up. Mean retinal sensitivity significantly decreased during follow-up only in the bilateral GA group (p= 0.0405 in the bilateral GA group vs p=0.5634 in the fellow eye CNV group).
Conclusions
The choroid shows different changes in GA, probably reflecting different GA phenotypes. These results should be taken into consideration when planning clinical trials to treat GA, because the effect varies depending on the individual phenotype.
Keywords: 412 age-related macular degeneration •
550 imaging/image analysis: clinical •
452 choroid