Macular Microvasculature Asymmetry Analysis for Evaluating Open-Angle Glaucoma in Diabetic Retinopathy Patients Treated With Pan-Retinal Photocoagulation.

PURPOSE: To evaluate the usefulness of vertical asymmetry analysis of macular microvasculature for diagnosis of open-angle glaucoma (OAG) in diabetic retinopathy (DR) patients who have undergone pan-retinal photocoagulation (PRP).

DESIGN

Retrospective, cross-sectional diagnostic evaluation.

METHODS

DR patients with PRP were categorized into those without OAG (Group 1) and those with OAG (Group 2). Peripapillary retinal nerve fiber layer (pRNFL) thickness and macular vessel density (VD) were measured, and the vertical difference in pRNFL (vdRNFL) and VD (vdVD) was determined as the absolute difference between the superior and inferior sectors. Diagnostic performance was analyzed by calculating the area under the curve (AUC).

RESULTS

Analyses included 128 eyes (Group 1: 68 and Group 2: 60). The mean pRNFL thickness was 93.9 ± 14.8 µm in Group 1 and 85.5 ± 14.4 µm in Group 2 (P = .009). The mean vdRNFL was 13.1 ± 10.9 µm in Group 1 and 14.4 ± 12.6 µm in Group 2 (P = .607). The mean VD was 15.9 ± 3.3 mm-1 in Group 1 and 15.3 ± 2.6 mm-1 in Group 2 (P = .380), whereas the vdVD was 0.6 ± 0.6 mm-1 in Group 1 and 1.6 ± 1.4 mm-1 in Group 2 (P < .001). The AUC for diagnostic accuracy was 0.812 for vdVD, significantly higher than that for other factors (all P < .001).

CONCLUSIONS

Relying on pRNFL thickness for OAG evaluation in PRP-treated patients is not recommended. Analysis of vertical microvasculature asymmetry can serve as a useful factor for diagnosing OAG.