INTRAOCULAR AND INTEROCULAR DIFFERENCES IN PARAFOVEAL VASCULAR DENSITY IN DIABETIC PATIENTS WITHOUT DIABETIC RETINOPATHY

Purpose: To evaluate the associations among optical coherence tomography angiography-measured vascular density (VD), intraocular and interocular VD differences, and clinical factors in diabetic patients without diabetic retinopathy. Methods: We retrospectively reviewed 94 Type 2 diabetic patients without diabetic retinopathy who had undergone optical coherence tomography angiography. Vascular density and vessel skeleton density were measured in a 3-mm central zone in the total capillary plexus, superficial capillary plexus, deep capillary plexus (DCP), and choriocapillaris layers. Intraocular VD difference was determined between the superior and inferior zones, while interocular VD difference was determined between both eyes of the patient. Associations between optical coherence tomography angiography parameters and clinical factors were evaluated. Results: Vascular density and intraocular and interocular VD differences were significantly associated with signal strength of the image, which was related with age and lens opacity. In multivariate analysis, diabetes duration was negatively associated with skeleton density in total capillary plexus and superficial capillary plexus layers, and positively associated with intraocular VD difference in superficial capillary plexus layer. Estimated glomerular filtration rate was negatively associated with intraocular skeleton density difference in total capillary plexus layer, interocular VD, and skeleton density differences in total capillary plexus layer. Conclusion: Intraocular and interocular VD difference may be an easy and sensitive way to detect subtle early microvascular changes in diabetic patients.