Blindness caused by diabetes: a systematic review and meta- analysis

Abstract

Visual impairment and blindness are important factors in assessing the quality of life and health. Diabetes can cause several complications in ophthalmic diseases that can affect the eye as an organ to an extent of the cornea to the optic nerve. Diabetes-specific retinopathy characterized by microaneurysm, hemorrhage, and exudate is one of the leading causes of vision loss in the world. Objectives: Considering the importance of blindness, as well as the vast global prevalence of diabetes and its role in blindness and health, there is a need for an investigation of these two categories together epidemiologically. Given that several studies have been conducted on the prevalence of blindness due to diabetes in different parts of the world u to this date, there is a need for a conclusion that summarizes the results of these studies and provides us with a clear view of the available data for planning, decision making, and effective interventions. Therefore, the objective of this study was to systematically review and meta-analyze the prevalence of diabetes-induced blindness in the population of diabetic patients as well as the blind in different countries and to assess other related background information. Methods: Available databases were searched to find related studies. The articles and documents obtained from the search were entered into the statistical population in several stages based on title, abstract, and the whole text after the screening and studies that met the inclusion criteria were included in the analysis. The included studies were evaluated by 2 experts using the JBI checklist. Relevant data were extracted from the studies using a designed table and finally, the data were analyzed using CMA software and by the Random Effect method. Results: Out of 5312 studies, 34 articles were entered into the systematic review and meta-analysis after applying the inclusion and exclusion criteria. The prevalence of blindness in the population of patients with diabetes was reported to be 2%. The overall prevalence of blindness due to diabetic retinopathy in the blind population was calculated to be 5%, and it was 4% in developing countries. Besides, it was 6% in developed, 3% in a sample of the normal population, and 7% in clinic/hospital samples. It was also calculated to be 4% by the method of examination and determination of visual acuity, 4% using PVA, and 6% based on BCVA.