COMPARATIVE ANALYSIS OF OPTICAL COHERENCE TOMOGRAPHY (OCT) PARAMETERS IN DIABETIC MACULAR EDEMA

Аннотация

Diabetic macular edema (DME) is a leading cause of visual impairment among patients with diabetic retinopathy and remains a major global health concern. Optical coherence tomography (OCT) has revolutionized the understanding and management of DME by providing high-resolution, quantitative, and non-invasive visualization of retinal microstructures. This study presents a comparative analysis of OCT parameters in patients with varying types and severities of DME. By evaluating central retinal thickness (CRT), macular volume (MV), and retinal layer morphology across different clinical subgroups, the research highlights correlations between OCT-derived metrics and visual acuity outcomes. The findings indicate that specific OCT biomarkers, including hyperreflective foci, disorganization of the retinal inner layers (DRIL), and subretinal fluid accumulation, serve as significant predictors of functional prognosis. The study emphasizes the clinical importance of quantitative OCT monitoring in guiding individualized therapeutic approaches and improving long-term visual outcomes in diabetic patients. Keywords: Diabetic macular edema; optical coherence tomography; retinal thickness; macular volume; visual acuity; biomarkers; diabetic retinopathy; retinal morphology; DRIL; hyperreflective foci. Introduction Diabetic macular edema represents one of the most vision-threatening complications of diabetic retinopathy, resulting from increased vascular permeability and accumulation of extracellular fluid within the macular region. As diabetes prevalence continues to rise globally, DME remains a critical cause of preventable blindness among working-age adults. The pathophysiology of DME involves chronic hyperglycemia-induced microvascular damage, disruption of the blood-retinal barrier, and inflammation-mediated cytokine release, leading to retinal thickening and photoreceptor dysfunction. The introduction of optical coherence tomography (OCT) has transformed diagnostic and monitoring strategies in ophthalmology. Unlike conventional fundus photography or fluorescein angiography, OCT offers cross- sectional imaging with micrometer-level resolution, enabling precise evaluation of retinal architecture and quantitative measurement of thickness changes. It plays a pivotal role in detecting subtle morphologic alterations that correlate with disease severity and therapeutic response. The comparative analysis of OCT parameters provides valuable insights into disease progression and visual function. Parameters such as central retinal thickness, total macular volume, and structural integrity of inner retinal layers serve as objective indicators of edema severity. 99 Noyabr, 2025-Yil Furthermore, qualitative OCT biomarkers such as cystoid spaces, hyperreflective foci, and disruption of the ellipsoid zone (EZ) contribute to understanding the pathophysiological mechanisms underlying visual loss. Despite the widespread use of OCT, variations in measurement outcomes across patient subgroups and treatment modalities necessitate further comparative studies. Therefore, the present research aims to perform a comprehensive analysis of OCT parameters among different types of DME, to elucidate their clinical significance and potential role in guiding therapeutic decision-making. Materials and Methods A total of 120 eyes from 85 patients with clinically diagnosed diabetic macular edema were enrolled in this observational study conducted at the Department of Ophthalmology, Samarkand State Medical University. Participants were divided into three groups based on OCT morphological patterns: spongiform (diffuse retinal thickening), cystoid, and serous retinal detachment types. Exclusion criteria included the presence of other retinal pathologies, previous macular surgery, or significant media opacity. All patients underwent a detailed ophthalmic examination, including best-corrected visual acuity (BCVA) using Snellen charts, intraocular pressure measurement, slit-lamp biomicroscopy, and dilated fundus examination. OCT imaging was performed using a spectral-domain OCT device (Heidelberg Spectralis, Heidelberg Engineering, Germany). Parameters measured included central retinal thickness (CRT), mean macular thickness, total macular volume, and qualitative assessment of structural abnormalities such as DRIL, EZ disruption, and presence of hyperreflective foci. Data were analyzed using statistical software (SPSS v26.0). Continuous variables were expressed as mean ± standard deviation, and intergroup comparisons were conducted using ANOVA and Pearson correlation tests. Statistical significance was set at p<0.05. Results The mean age of participants was 58.7 ± 9.4 years, with a male-to-female ratio of 1.3:1. The average duration of diabetes was 11.2 ± 4.8 years. The mean central retinal thickness (CRT) across all eyes was 452.6 ± 98.5 µm, significantly higher than the control group (p<0.001). Among subtypes, cystoid DME demonstrated the highest CRT (512.8 ± 102