Reliability of confocal white-light fundus imaging for measurement of retina pigment epithelial atrophy in age-related macular degeneration

Purpose: To assess the reproducibility of confocal white-light color fundus photography (C-CFP) for the measurement of retinal pigment epithelial atrophy in comparison with confocal blue-light fundus autofluorescence (FAF) imaging and flash color fundus photography (F-CFP). Methods: In this prospective study, eyes with age-related macular degeneration associated with evidence of retinal pigment epithelial atrophy were imaged by C-CFP, F-CFP, and FAF. Intergrader reproducibility of each modality was assessed by comparison of manual measurements by two expert graders. Results: The mean areas of atrophy measured by the 2 graders were 6.67 ± 6.39, 6.35 ± 6.13, and 6.07 ± 5.48 mm ² for FAF, C-CFP, and F-CFP, respectively. The mean differences between the 2 graders in measuring the atrophic areas were 0.52, 0.69, and 1.62 mm ² for the three modalities. The intraclass correlation coefficient between the 2 graders for each modality was 0.998, 0.990, and 0.961, respectively. Conclusion: Measurements of atrophy from C-CFP were similar to those obtained by FAF and F-CFP. The grading reproducibility for C-CFP, however, was better than that for F-CFP and approached the level of FAF imaging. The use of C-CFP as a tool for quantitatively monitoring atrophic age-related macular degeneration lesions warrants further study, particularly in the context of clinical trials.