Diagnostic Abilities of the Optical Microangiography Parameters of the 3×3 mm and 6×6 mm Macular Scans in Glaucoma

Purpose: To evaluate the diagnostic abilities of macular vessel length and perfusion densities measured with optical microangiography (OMAG) over a 3×3 mm and a 6×6 mm region, and to compare these with macular ganglion cell-inner plexiform layer (GCIPL) thickness in eyes with primary open-angle glaucoma (POAG). Methods: In a cross-sectional study, 96 eyes of 57 control subjects and 88 eyes of 57 POAG patients underwent macular imaging with optical coherence tomography. Area under receiver operating characteristic curves (AUC) and sensitivities at 90% specificity of OMAG and GCIPL parameters were evaluated. Results: Most OMAG parameters of the 3×3 mm macular scan and all inner sector parameters of the 6×6 mm scan were similar ( P >0.05) in the POAG and control eyes. All outer sector OMAG parameters of the 6×6 mm scan were significantly less ( P <0.05) in the POAG eyes. AUC and sensitivity at 90% specificity of the best parameter of the 3×3 mm OMAG scan (inner temporal vessel length density; 0.65% and 26%, respectively) were statistically similar ( P >0.05) to that of the 6×6 mm scan (outer inferior vessel length density; 0.72% and 30%, respectively). AUC and sensitivity of the best GCIPL thickness parameter (inferotemporal GCIPL thickness, 0.84% and 67%) were significantly better ( P <0.05) than that of the vessel length densities. Conclusions: The outer sector measurements of the 6×6 mm macular OMAG scans seem to be better than the inner sector measurements in diagnosing glaucoma. The GCIPL thickness measurements were significantly better than all macular OMAG parameters in diagnosing glaucoma.