The prevalence, pattern and associations of diabetic retinopathy in black african diabetic patients attending medical diabetes clinic at Kenyatta National Hospital

Abstract

Introduction: Over the last ten years. there has been a rise in the number of patients with Diabetes mellitus and the risk of visual loss from Diabetic retinopathy. A study on the magnitude and pattern of DR carried out at Kenyatta National Hospital in 1999 showed the prevalence of DR to be high (49.8%) 9. Recommendations following this study have been implemented to various extents. Since then, there have also been changes in the treatment of OM. This is a ten-year review of the situation of DR at KNH reflecting dynamics in epidemiology and management of diabetes mellitus and diabetic retinopathy.

Aim: To determine the prevalence, pattern and associations of diabetic retinopathy In black African diabetic patients attending medical Diabetes Clinic at KNH.

Design: A cross-sectional hospital based study was carried out from March 2011 to September 20 II. A total of 213 patients were selected using systematic sampling. Blood pressure and blood sugars were taken. A detailed ocular examination was done and HbA 1 c was assessed. DR was graded using ETDRS guidelines (Appendix 4).

Results: The prevalence of DR in patients attending KNH medical diabetes clinic was found to be 31.9%. Of these, 8.8% had Clinically significant Macula Oedema. A study done in 1999 by Kariuki et al at KNH found the prevalence of DR to be 49.8% with 40.3% of these having CSME and majority of the patients with DR having NPDR without macula oedema. Out of the 213 patients studied, 2 patients had NPDR not amenable to photocoagulation. Those who had previous fundus examination were 47.2% and 5.5% of the total number of patients had received laser treatment for either PDR or CSME.

In the study by Kariuki et alin 199 at KNH, only 18% of the patients had previous fundus examination/.None had ever been screened for DR and none had ever had laser treatment. There was a statistically significant association between duration of DM and development of DR. Patients with higher systolic and diastolic blood pressure had a higher prevalence of DR. Patients with high levels ofHbAlc had more severe DR. However, this was also not statistically significant. Duration of OM had significant association with DR(p<O.OO 1).

Conclusion: The prevalence of OR in patients attending medical diabetes clinic was 31.9%. This was lower than the prevalence in a previous study (49.8%). Those previous fundus examination by an ophthalmologist were 47.2%.In the previous study, only 18%

had previous fundus examination. Most of the patients with no diabetic retinopathy had high HbAlc, while others with high grades of DR had normal HbAlc.This could have been due to due to poor glucose control at the beginning of treatment. predisposing patient to developing DR despite good glycaemic control later in their treatment, thus showing the need for strict glycaemic control right from the beginning of treatment.