Influence of type 2 diabetes mellitus on the central retinal area in patients with proliferative diabetic retinopathy

Abstract

Background. The purpose of the study was to determine whether the state of the central retinal area depends on the duration of type 2 diabetes mellitus (DM) and glycemia level in patients with proliferative diabetic retinopathy (DR). Materials and methods. The study included 62 patients with type 2 DM who according to the results of clinical and instrumental examination were divided into non-proliferative (n = 31, 31 eyes) and proliferative DR (n = 31, 31 eyes) groups using the Early Treatment of Diabetic Retinopathy Study classification. An ophthalmologic examination included visual acuity check with optimal optical correction, tonometry, biomicroscopy, ophthalmoscopy and optical coherence tomography. Results. In patients with proliferative DR in the subcompensated stage of DM, the thickness and volume of the macular retina were 309.0 ± 130.0 μm and 7.6 ± 2.7 mm3, respectively, whereas in the decompensa­ted stage — 287.0 ± 40.0 μm and 7.80 ± 0.57 mm3 (p > 0.05). With the progression of DR, a statistically significant decrease in the optimal correlated visual acuity (p = 0.012) and an increase in the volume of the macular retina (by 6.9 %, p = 0.034) were revealed. More demonstrative changes in the retina tissue (p < 0.05) were revealed in patients with proliferative DR complicated by macular edema. Conclusions. In patients with proliferative DR, there was no difference in the state of the eye in subcompensated and decompensated stages of type 2 DM. Progression from non-proliferative to proliferative DR is manifested by a decrease in the correlated visual acuity, an increase in the thickness and volume of the macular retina in the central zone, which may be determined by the development of edema due to the progression of the pathological process.

Keywords

• type 2 diabetes mellitus
• diabetic retinopathy