Retinal Nerve Fiber Layer Decrease during Glycemic Control in Type 2 Diabetes

Abstract

Purpose. To assess an effect of glycemic control on retinal nerve fiber layer (RNFL) in type 2 diabetes mellitus. Methods. Thirty-eight eyes of 38 patients with type 2 diabetes undergoing blood glucose regulation were enrolled. All patients were examined at (1) initial visit, (2) 1 month, (3) 2 months, and (4) 4-month after the initial examination. On each occasion, glycosylated hemoglobin (HbA1c) levels and optical coherence tomography (OCT) scanning for RNFL thickness were evaluated. 360 degree circular OCT scans with a diameter of 3.4 mm centered on the optic disc were performed. Results. Significant RNFL decrease was seen in the superior area between initial and 4 months examination (P = .043). The relationship between the changes in HbA1c and the changes in RNFL thickness was observed in superior, temporal, and inferior area (P < .05) at 4 months. Conclusions. This study suggests that the glycemic control affects RNFL within 4 months.

Retinal thickness profile of individuals with diabetes

“…Higher glycaemic levels have been reported to be related to development and progression of retinopathy in the Diabetes Control and Complications Trial (DCCT) and in the Wisconsin Epidemiologic Study of Diabetic Retinopathy (WESDR); however, acute or rapid reductions in HbA 1c levels were associated with worsening of DR . Also, after 4 months of strict metabolic control, RNFL thickness reduced further compared to baseline values . The findings reported in previous studies and that from our study may indicate (1) a nonlinear relationship between retinal tissue thickness and HbA 1c levels, and (2) the extent or the percentage of reduction in glycaemic levels may be equally important, in addition to absolute HbA 1c levels.…”

“…The association between HbA 1c levels and duration of diabetes with inner retinal thickness has been investigated, revealing a reduction in the RNFL thickness after 4 months of strict control of HbA 1c levels . An inverse correlation has been reported between duration of diabetes and retinal tissue thickness .…”

Correlation of retinal nerve fibre layer and macular thickness with serum uric acid among type 2 diabetes mellitus

“…Another study found the superior quadrant to be more predisposed to damage and a higher rate of cellular death, which resulted in RNFL thinning [26]. Our study demonstrated a lack of thinning of the RNFL at the nasal quadrants.…”

Spectral-Domain Optical Coherence Tomography Features in Open-Angle Glaucoma With Diabetes Mellitus and Inadequate Glycemic Control

“…11 On the other hand, another study reported that RNFL thickness decreased after 4 months of glycemic control, which was explained by the transient deterioration of diabetic retinopathy following intensive glycemic control. 12 In this study, among a number of parameters evaluated, cube average thickness, average GCIPL, inferonasal GCIPL, inferior GCIPL, and inferotemporal GCIPL thickness parameters measured in the macular area were positively correlated with HbA 1c levels at the time of OCT examination. Retinal changes in DM can be due to a variety of pathways involving several factors.…”