Purpose
Previous results from the Comparison of Age-related Macular Degeneration (AMD) Treatments Trials (CATT) showed that both at baseline and follow-up, eyes with intraretinal fluid (IRF) had worse visual acuity (VA) than eyes without IRF. We examined whether CATT eyes with a petaloid configuration of macular edema (PME) on baseline fluorescein angiography (FA), as a subtype of IRF, had different outcomes.
Methods
The baseline FA images of all CATT study eyes were evaluated for PME by one of two physician readers. PME was defined as honeycombed patterns of hyperfluorescence surrounding the foveal center, with features of pooling in well-defined foveal/parafoveal spaces. PME confirmed by consensus of both readers were included in analyses. Grading of other characteristics on optical coherence tomography (OCT) and photographic images at baseline and two-year follow-up were completed by readers at the CATT Reading Centers. Three groups were formed based on baseline PME and IRF status —those with 1) PME; 2) IRF but no PME; 3) neither PME nor IRF.
Results
Among 1158 participants having images of sufficient quality for determining PME and IRF, at baseline, 99 (9%) participants had PME, 788 (68%) had IRF but no PME, and 271 (23%) had neither. At baseline, eyes with PME had worse mean VA (letters [standard error]) than eyes with IRF but no PME and eyes with neither IRF nor PME (53 [1.5] vs 60 [0.5] vs 66 [0.7] letters, respectively, p<0.001). The PME group also had higher mean total central retinal thickness (CRT, μ) on OCT (512 [16] vs 472 [7] vs 404 [11], p<0.001) and higher proportion of classic CNV (71% vs 38% vs 31%, p<0.001). PME eyes had the largest decrease in CRT at two years (-241μ [20] vs -174μ [8] vs -113μ [10], p<0.001). VA improvement from baseline was similar at two years among the three groups (p=0.13), however, eyes with PME started and continued with the poorest VA throughout follow-up (Figure 1; p<0.001 at every time point).
Conclusions
In CATT, PME eyes had worse VA, higher CRT and were associated with classic CNV lesions at baseline compared to non-PME eyes. Eyes with PME showed improvement of VA and CRT at two years, but continued to have lower VA compared to eyes without PME, suggesting PME may be a marker for a physiologic process within the retina associated with poor visual function.