Diagnostic capability of perimetry and optical coherence tomography based retinal thickness measurements in diabetic patients with no or mild retinopathy.

PURPOSE: This study aimed to compare and evaluate the diagnostic potential of visual field parameters and different retinal layers thicknesses among diabetic patients with and without diabetic retinopathy and non-diabetic controls.

METHODS

A total of 174 participants were enrolled and divided equally into three groups of 58 subjects: (1) healthy controls, (2) diabetic patients without diabetic retinopathy (NoDR), and (3) diabetic patients with mild non-proliferative diabetic retinopathy (NPDR). Retinal layer thicknesses (eight layers × five macular sectors) and visual field (mean deviation, MD; pattern standard deviation, PSD) were compared using one-way ANOVA with Tukey post-hoc testing. Pearson correlations between MD/PSD and retinal layer thickness were computed to test structure-function association.

RESULTS

Temporal NFL thickness was markedly greater in NPDR (25.14 ± 8.62 µm) than in NoDR (19.43 ± 4.17 µm) or controls (19.34 ± 5.15 µm; P < 0.001), and this difference persisted after age adjustment (P < 0.001). MD showed good diagnostic performance for NoDR vs control (AUC 0.766) and NPDR vs control (AUC 0.876), outperforming PSD (AUC 0.646 and 0.719, respectively); the NoDR-vs-control MD difference remained significant after age adjustment (P = 0.011) but was substantially attenuated, and the PSD group difference was fully explained by age (age-adjusted P = 0.80). No meaningful correlation was found between MD/PSD and any retinal layer thickness (all |r| < 0.21).

CONCLUSION

Temporal NFL thickening in NPDR and reduced visual field MD represent the most robust structural and functional abnormalities in this study.