VALIDATION OF THE RECENTLY DEVELOPED ATN CLASSIFICATION AND GRADING SYSTEM FOR MYOPIC MACULOPATHY

Abstract

To validate the recently developed ATN grading system for myopic maculopathy to classify eyes with pathologic myopia. Cross-sectional study. A series of consecutive eyes diagnosed with pathologic myopia and signs of myopic maculopathy (grade ≥1 for atrophic, tractional, or neovascular components of the ATN), with a refractive error > -6.0 diopters (D), were included. All patients underwent complete ophthalmological examination including fundus photography and swept-source optical coherence tomography. Six observers graded each eye twice using the ATN system (≥15 days between assessments) based only on the aforementioned data. Sixty eyes from 47 patients (61.7% female) were graded. Mean patient age was 63.2 ± 11.7 years. The mean spherical equivalent was -13.8 ± 6.5 D. Mean axial length was 28.6 ± 2.16 mm. Overall, the mean intraobserver agreement (%) for the same image was 92.0%, and the mean interobserver agreement for the second image was 77.5%. The weighted Fleiss k showed excellent correlation (k > 0.8) for the traction and neovascularization components and good correlation (0.75) for atrophy. Interobserver agreement for each of these three components was 95.2%, 98.4%, 95.0%, respectively. Application of the ATN resulted in high intraobserver and interobserver correlation, underscoring the reproducibility of the system.