Department of Ophthalmology, Vivekananda Polyclinic and Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
Department of Ophthalmology, Regional Institute of Ophthalmology, Institute of Medical Sciences, BHU, Varanasi, Uttar Pradesh, India.
Indian J Ophthalmol. 2024 Aug 1;72(8):1186-1191. doi: 10.4103/IJO.IJO_2981_23. Epub 2024 Jul 29.
The current study was aimed to find correlation of glycosylated hemoglobin with retinal nerve fiber layer thickness (RNFLT) and central macular thickness (CMT) in the diabetic population in North India.
This was a cross-sectional observational study of 300 diabetic patients divided equally in two groups with and without retinopathy, and 150 people were included as control. The study was conducted from October 2020 to August 2022. All patients underwent slitlamp fundoscopy with a +78 D lens, and spectral-domain (SD) optical coherence tomography was performed to measure the RNFLT and CMT, and the staging of retinopathy was done as per the ETDRS classification. Along with that, blood investigations were ordered, including fasting (FBS) and post-prandial (PPBS) blood sugar and glycosylated hemoglobin (HbA1c). Quantitative variables were compared using one-way analysis of variance, or Kruskal-Wallis test was applied for inter-group comparison, followed by a Student Newman Keuls Test.
The mean age of the patients in the diabetic group with retinopathy was 52.62 ± 9.38 years. The overall male: female ratio was 3:2. The mean FBS in the diabetic group with retinopathy was 146.54 ± 45.40mg/dl; the PPBS and HbA1c in the same were 210.39 ± 63.71mg/dl and 7.85 ± 1.33%, respectively. RNFL thinning was found in all four quadrants in diabetics irrespective of the status of retinopathy (P-value = 0.000) with a significant weak negative (r<0.4) correlation of glycosylated hemoglobin values with RNFLT in the inferior (r value = -0.300, P-value = 0.000) and superior (r value = -0.236, P-value = 0.004) quadrants of right eyes and in inferior (r value = -0.176, p- value = 0.031), superior (r value = -0.222, P value = 0.006), and nasal quadrants (r value = -0.166, p- value = 0.043) of left eyes in diabetics with retinopathy. However, in diabetics without retinopathy, no correlation was found. On correlating HbA1c with CMT, a weak positive (r<0.3) association existed in both eyes in the diabetic group without retinopathy (r = 0.020 and 0.048 for OD and OS, respectively) and diabetics with retinopathy (r = 0.152 and 0.127 for OD and OS, respectively). However, the association was not found to be significant in either of the groups (P-value > 0.05).
The study concluded that neurodegeneration occurs in diabetic retinopathy as evident with nerve fiber layer thinning, and it is negatively correlated with glycosylated hemoglobin (HbA1c).
本研究旨在探讨北印度糖尿病患者糖化血红蛋白（HbA1c）与视网膜神经纤维层厚度（RNFLT）和中心黄斑厚度（CMT）的相关性。
这是一项横断面观察性研究，纳入了 300 名糖尿病患者，分为有和无视网膜病变两组，每组 150 人，同时纳入 150 名健康对照者。研究于 2020 年 10 月至 2022 年 8 月进行。所有患者均行裂隙灯眼底镜检查（+78D 镜片），并进行频域光学相干断层扫描（SD-OCT）测量 RNFLT 和 CMT，根据 ETDRS 分类进行视网膜病变分期。同时，进行了血液检查，包括空腹（FBS）和餐后（PPBS）血糖和糖化血红蛋白（HbA1c）。定量变量采用单因素方差分析进行比较，组间比较采用 Kruskal-Wallis 检验，然后采用 Student-Newman-Keuls 检验。
有视网膜病变的糖尿病组患者的平均年龄为 52.62±9.38 岁。总体男女比例为 3:2。有视网膜病变的糖尿病组患者的平均 FBS 为 146.54±45.40mg/dl；PPBS 和 HbA1c 分别为 210.39±63.71mg/dl 和 7.85±1.33%。无论是否存在视网膜病变，糖尿病患者的所有四个象限均出现 RNFL 变薄（P 值均<0.000），且 HbA1c 值与右眼下方（r 值=-0.300，P 值=0.000）和上方（r 值=-0.236，P 值=0.004）象限以及左眼下方（r 值=-0.176，P 值=0.031）、上方（r 值=-0.222，P 值=0.006）和鼻侧象限（r 值=-0.166，P 值=0.043）的 RNFLT 呈弱负相关（r<0.4）。然而，在无视网膜病变的糖尿病患者中，未发现相关性。将 HbA1c 与 CMT 相关联时，在无视网膜病变的糖尿病组（OD 为 0.020，OS 为 0.048）和有视网膜病变的糖尿病组（OD 为 0.152，OS 为 0.127）中，双眼均存在弱正（r<0.3）关联。然而，两组的关联均无统计学意义（P 值均>0.05）。
本研究表明，糖尿病性视网膜病变患者存在神经退行性变，表现为神经纤维层变薄，与糖化血红蛋白（HbA1c）呈负相关。
