Evaluation of semiautomated measurement of geographic atrophy in age-related macular degeneration by fundus autofluorescence in clinical setting.

Purpose: To assess intraobserver and interobserver agreement among physicians with different degrees of clinical experience, using a novel fundus autofluorescence semiautomated software for quantification of geographic atrophy in clinical setting. Methods: Fundus autofluorescence frames (excitation: 488 nm; emission: 500–700 nm) of 29 eyes (20 patients; mean age, 79.6 ± 6.2 years) with geographic atrophy secondary to age-related macular degeneration, and no signs of choroidal neovascularization, were analyzed using Region Finder, a semiautomated software embedded in Spectralis (Heidelberg Engineering, Heidelberg, Germany). For each study eye, semiautomated atrophy identification and quantification were independently performed, twice (in a 2-week time frame), by 3 readers with different degrees of clinical experience (2 fellows, and 1 resident). Intraobserver and interobserver agreements were assessed. Results: Mean difference in intraobserver agreement (Bland–Altman statistics) ranged from −0.17 mm2 to 0.13 mm2. Intraobserver agreement was excellent until the geographic atrophy threshold value of 15.72 mm2. Variability correlated with the size of atrophy. Mean difference in interobserver agreement (Bland–Altman statistics) ranged from −0.25 mm2 to 0.27 mm2, with no significant difference between senior and junior readers. Multifocal lesion or foveal involvement in atrophy was not the cause of disagreement. Conclusion: Region Finder is a reliable tool for the identification and quantification of geographic atrophy in patients with age-related macular degeneration, in a clinical setting even when performed by junior reader.