Hyperreflective Abnormal Areas in the Middle Retinal Layers on En Face Optical Coherence Tomography for Diagnostic Discrimination in Diabetic Eyes.

OBJECTIVE

To evaluate whether hyperreflective lesions on en face optical coherence tomography of the middle retinal layers, which we label as hyperreflective abnormal areas (HAAs), improve the distinction of referable and vision-threatening diabetic retinopathy (DR), beyond established clinical factors.

DESIGN

Accuracy analysis of revised treatment referral criteria.

PARTICIPANTS

Two hundred seventy-five eyes from 185 patients with diabetes without center-involving diabetic macular edema, encompassing a broad range of DR severity.

METHODS

HAAs were manually quantified on averaged en face optical coherence tomography of a middle-retina slab, segmented from 10 µm above the inner plexiform layer to 10 µm below the outer plexiform layer, and quantified as percentage HAA of the analyzable retinal area. Generalized estimating equation logistic regression models were constructed to distinguish referable and vision-threatening DR. A base model included clinical parameters of age, sex, duration of diabetes, hemoglobin A1c, and hypertension, while a full model additionally incorporated HAAs. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), internal cross-validation, and calibration.

MAIN OUTCOME MEASURES: Model discrimination and effect size of HAAs for distinguishing referable and vision-threatening DR.

RESULTS

For referable DR, the full model showed significantly improved discrimination compared with the base model (AUC 0.969 vs 0.865; ΔAUC 0.104, P = .002). HAAs were independently associated with referable DR, with an odds ratio of 3.42 per 0.1-percentage point increase (95% CI, 2.37-7.97). Internal cross-validation supported the robustness of the improved discrimination for referable DR. For vision-threatening DR, the full model showed higher discrimination (AUC 0.865 vs 0.778), but did not reach significance (P = .126). HAAs were positively associated with vision-threatening DR, with an odds ratio of 1.23.

CONCLUSIONS

Middle retinal layer HAAs identified eyes with referable DR beyond established clinical factors. The association of HAAs with vision-threatening DR was directionally consistent but did not improve model discrimination beyond clinical factors. Because HAAs may capture lesion-agnostic structural signatures of microvascular pathology in the middle retina, they may serve as a promising biomarker for diagnostic discrimination of high-risk diabetic eyes in the absence of center-involving diabetic macular edema.