Comparison of Optical Coherence Tomography Structural Parameters for Diagnosis of Glaucoma in High Myopia

Diagnosis of glaucoma in highly myopic eyes is challenging. This study compared the glaucoma detection utility of various optical coherence tomography (OCT) parameters for high myopia.To compare the diagnostic accuracy of single OCT parameters, the University of North Carolina (UNC) OCT Index, and the temporal raphe sign for discrimination of glaucoma in patients with high myopia.This was a retrospective cross-sectional study conducted from January 1, 2014, and January 1, 2022. Participants with high myopia (axial length ≥26.0 mm or spherical equivalent ≤-6 diopters) plus glaucoma and participants with high myopia without glaucoma were recruited from a single tertiary hospital in South Korea.Macular ganglion cell-inner plexiform layer (GCIPL) thickness, peripapillary retinal nerve fiber layer (RNFL) thickness, and optic nerve head (ONH) parameters were measured in each participant. The UNC OCT scores and the temporal raphe sign were checked to compare diagnostic utility. Decision tree analysis with single OCT parameters, the UNC OCT Index, and the temporal raphe sign were also applied.Area under the receiver operating characteristic curve (AUROC).A total of 132 individuals with high myopia and glaucoma (mean [SD] age, 50.0 [11.7] years; 78 male [59.1%]) along with 142 individuals with high myopia without glaucoma (mean [SD] age, 50.0 [11.3] years; 79 female [55.6%]) were included in the study. The AUROC of the UNC OCT Index was 0.891 (95% CI, 0.848-0.925). The AUROC of temporal raphe sign positivity was 0.922 (95% CI, 0.883-0.950). The best single OCT parameter was inferotemporal GCIPL thickness (AUROC, 0.951; 95% CI, 0.918-0.973), and its AUROC difference from the UNC OCT Index, temporal raphe sign, mean RNFL thickness, and ONH rim area was 0.060 (95% CI, 0.016-0.103; P = .007); 0.029 (95% CI, -0.009 to 0.068; P = .13), 0.022 (95% CI, -0.012-0.055; P = .21), and 0.075 (95% CI, 0.031-0.118; P < .001), respectively.Results of this cross-sectional study suggest that in discriminating glaucomatous eyes in patients with high myopia, inferotemporal GCIPL thickness yielded the highest AUROC value. The RNFL thickness and GCIPL thickness parameters may play a greater role in glaucoma diagnosis than the ONH parameters in high myopia.