Classification of diabetic macular edema cases based on optical coherence tomography images, evaluation of morphological features and determination of the relationship of systemic mediators

Purpose: To classify diabetic macular edema (DME) according to its morphological characteristics by examining optical coherence tomography (OCT) scans, to evaluate the effect of some markers, visual acuity and blood glycosylated hemoglobin (HbA1C) levels on DME types. Materials and Methods; the OCT images of DME patients who had not received treatment before were evaluated and divided into three groups as diffuse macular edema (dME), cystoid macular edema (CME) and cystoid degeneration (CD). In OCT images of the patients, presence of subretinal fluid (SRS), disorganization of inner retinal layers (DRIL), ellipsoid zone (EZ) damage, external limiting membrane (ELM) damage, exudates, hyperreflective dots (HRD), epiretinal membrane (ERM) and vitreomacular traction (VMT) were evaluated. After the blood HbA1C levels of the patients were obtained, the effect of the DME type together with the OCT findings were examined and the factors affecting the visual acuity were assessed. Results; 746 eyes of 538 patients were evaluated and 55.1% were in the CME group, 40.6% in dME and 3.8% in the CD group. It was observed that the integrity of ELM and EZ was impaired in 11.58% and 11.09%, respectively. When SRS, DRIL, HRD, exudates, VMT and ERM were examined, the rates of 16.7%, 19.23%, 28.83%, 54.40%, 2.76% and 15.8% were obtained, respectively. While the group with the best visual acuity was dME, the group with the worst was the KD group. While SRS, HRD and exudates were most frequently observed in CME; DRIL, ELM and EZ damages were most frequently observed in the KD group. Neither DME type nor visual acutiy had significant relationship with HbA1C level. Conclusion; the group with the lowest visual acuity and the most damage to the outer retinal layers is the KD group. Presence of SRS, DRIL, HRD, exudate and ERM are also among the reasons that decrease visual acuity in DME. HbA1C level has no effect on DME type or other OCT findings.