Incidence and progression of diabetic retinopathy within a private diabetes mellitus clinic in South Africa

Retinopathy among Adult Diabetics and Its Predictors in Northwest Ethiopia

BACKGROUND

Diabetic retinopathy is the leading cause of blindness among working-aged adults worldwide, including developing countries such as Ethiopia, and the burden of diabetes-related blindness is undeniably posing a massive challenge to the health care system. Diabetes and its micro- and macrovascular complications are becoming more prevalent among Ethiopian diabetics. For that reason, the purpose of this study was to assess the incidence of diabetic retinopathy and its predictors among diabetics in Ethiopia.

METHODS

A hospital-based retrospective cohort study was conducted using 494 randomly selected diabetics aged above 18 years at Felege Hiwot Comprehensive Specialized Hospital from 2011 through 2014 and was followed until December 2019. The preliminary and longitudinal data was abstracted into demographics, clinical, and physiological attributes using a standardized structured questionnaire. The collected data was entered into the system using EpiData version 4.2 and analyzed using STATA version 14.0. The survival experience of the patients was assessed using the Kaplan-Meier survivor function. The predictors of diabetic retinopathy were identified by the Cox proportional hazard model. Bivariable and multivariable Cox proportional hazard models were computed, and variables having a P value of < 0.05 in the multivariable Cox proportional hazard model were declared as significant predictors of diabetic retinopathy.

RESULTS

During the follow-up, the overall incidence rate of diabetic retinopathy was 48 per 1000 person-years (95% CI: 40.0-57.0). Age in years (AHR 1.02; 95% CI: 1.00-1.04), fasting blood sugar level (AHR 1.02; 1.00-1.04), hypertension (AHR 2.61; 95% CI: 1.47-4.63), DM patients who had LDL > 100 mg/dl (AHR 2.73; 95% CI: 1.32-5.64), total cholesterol > 200 mg/dl (AHR 2.22; 95% CI: 1.08-4.55), and positive proteinuria (AHR 1.74; 95% CI: 1.10 -2.73) were found to be the significant predictors of diabetic retinopathy.

CONCLUSION

The overall incidence rate of diabetic retinopathy was found to be high in both type 1 and type 2 DM. Age, fasting blood sugar levels, hypertension, proteinuria, dyslipidemia, and high systolic blood pressure were all predictors of the development of diabetic retinopathy. Controlling glycemia, dyslipidemia, proteinuria, and blood pressure is critical for halting the progression of diabetic retinopathy.

Glycated hemoglobin A1C level and the risk of diabetic retinopathy in Africa: A systematic review and meta-analysis

BACKGROUND AND AIMS

Diabetic retinopathy is a frequent cause of acquired blindness worldwide. Various studies have reported the effects of glycemic control on the risk of diabetic retinopathy, but the results remain inconclusive. Therefore, this meta-analysis was performed to determine the association between glycated hemoglobin A1C levels and diabetic retinopathy in Africa.

METHODS

A systematic search was performed using the PubMed, African Journals Online, Google Scholar, Scopus, and Wiley Online Library from inception to June 11, 2020, for observational studies addressing the association of hemoglobin A1c levels with diabetic retinopathy. The I² statistic was used to check heterogeneity across the included studies. A random-effects model was applied to estimate the pooled effect size (OR) and respective 95% confidence interval across studies. A funnel plot and Egger's regression test were used to determine the presence of publication bias. Sensitivity analysis was used to determine the effect of a single study on the overall estimation. All statistical analyses were performed using STATA™ Version 14 software.

RESULT

A total of 23 articles with 18,099 study participants were included in this meta-analysis. In the present review, when HbA1c was analyzed as a categorical variable, poor glycemic control (HbA1c >7%) was associated with an increased risk of diabetic retinopathy when compared with good glycemic control (OR = 1.25; 95% CI; 1.14, 1.38). Similarly, when HbA1c was analyzed as a continuous variable, a higher HbA1c was associated with an increased risk of diabetic retinopathy (MD: 0.42, 95% CI; 0.11, 0.98).

CONCLUSION

Our meta-analysis indicated evidence for poor glycemic control as an independent risk factor for the development of diabetic retinopathy in patients with diabetes mellitus. Therefore, the authors suggest that clinicians should advise their patients with diabetes to maintain their HbA1c levels within the normal range.