%0 Journal Article %T Detecting Pre and Early Retinal Changes in Patients with Type 2 Diabetes Mellitus Using Optical Coherence Tomography Angiography %A Paul Mwale %A Hanyu Zheng %A Yan Zheng %A Bin Jiang %A Ying Li %A Yujing Wang %A Fang Li %A Xiaomin Chen %A Min Ke %J Open Journal of Ophthalmology %P 369-384 %@ 2165-7416 %D 2024 %I Scientific Research Publishing %R 10.4236/ojoph.2024.144034 %X Background: Studies conducted previously indicated that gradual vascular changes in diabetic retinopathy (DR) include reduction in retinal vascular density and choroidal thickness. One device that can be used to detect these early changes is optical coherence tomographic angiography (OCTA). Objective: To detect the pre and early diabetic retinal and choroidal microvascular changes in patients with type 2 diabetes mellitus using OCTA. Methods: A total of 188 eyes were included in the study that was conducted at Zhongnan Hospital of Wuhan University Ophthalmology Department. Participants were divided into three groups: controls (90 eyes), pre-DR (70 eyes) and early-DR (28 eyes). We evaluated the changes in vascular density of deep capillary plexus (DCP), intermediate capillary plexus (ICP), superficial vascular complex (SVP), choroidal thickness (CT) and choroidal vascular index (CVI). Results: Vessel density (VD) of deep capillary plexus (DCP) and intermediate capillary plexus (ICP) at 3 × 3 mm was not significant. However, superficial vascular plexus (SVP), was significant in superior quadrant, p = 0.033. In DCP layer at 6 × 6 mm, significant difference was noted superiorly, p = 0.023 and ANOVA p = 0.033. However, ICP layer showed significant changes temporaly and inferiorly in 1 - 3 mm and 1 - 6 mm retinal rings, p < 0.05. The SVP layer showed a similar result to ICP with significant difference in temporal region, p < 0.005. Choroidal thickness (CT) and choroidal vascular index (CVI) at 15 × 12 mm, showed significant difference peripherally in the superior, temporal and inferior regions, p < 0.005. Conclusion: Our results reveal that although there were no clinical manifestations in the control group and the pre-DR group, changes in retinal and choroidal blood flow density had already occurred in the pre-DR group through OCTA detection, suggesting that early detection of the lesions provides an objective basis to prevent further retinal microvascular damage. Using OCTA parameters at 3 × 3 mm, 6 × 6 mm and 15 × 12 mm scan radius at different layers of the retina and choroid, we are able to detect early retinal microvascular and choroidal changes in patients with pre-DR and early-DR thereby saving the costs of dealing with advanced diabetic eye disease. OCTA therefore becomes a fundamental tool for the non-invasive diagnosis and prognosis of DR. %K OCTA %K Pre-DR %K Early-DR %K Vessel Density %U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=136266