Visual impairment and blindness in diabetic retinopathy.

Abstract

Background: Diabetic retinopathy (DR) is a major microvascular complication of diabetes mellitus (DM) and a leading cause of preventable visual impairment (VI) and blindness worldwide. The rising global prevalence of DM, particularly in low- and middle-income regions such as the Middle East, necessitates the collection of localized data on DR-related VI. Despite growing public health concerns, limited research has been conducted in the Gulf region, including Oman. This study aimed to assess the prevalence and severity of VI associated with DR and identify its key risk factors among patients with types I and II DM in Al Buraimi, Sultanate of Oman.

Methods: A retrospective cross-sectional study was conducted at Buraimi Hospital and Polyclinic in Oman between June 2023 and January 2024. Medical records of patients with type I or II DM and a confirmed diagnosis of DR were reviewed. Best-corrected distance visual acuity was assessed using a Snellen chart, and fundus examinations were performed using both direct and indirect ophthalmoscopy for DR detection and staging. VI was classified according to the WHO criteria. Relevant demographic and clinical data, including age, duration of DM, and duration of DR, were extracted. Coexisting ocular conditions were also documented.

Results: A total of 218 participants were included, with a mean age of 57.5 years; 52.3% (n = 114) were male and 47.7% (n = 104) female. Most participants had no VI (n = 131, 60.1%), whereas mild VI (n = 58, 26.6%) was the most frequent type of VI. A significant association was detected between DR severity and VI levels (P < 0.01); blindness occurred only in patients with severe nonproliferative DR (n = 1) and proliferative DR (n = 8). Age and DR duration were significantly associated with increasing VI severity (both P < 0.05), with each additional year increasing the odds by 4% and 12%, respectively. No significant association was observed between DM duration and VI severity (P > 0.05). Cataract (n = 131) was the most common coexisting ocular condition.

Conclusions: The frequency of VI among patients with DR was relatively high, and its severity was significantly associated with older age and longer DR duration. Blindness occurred only in more severe DR stages, reinforcing the value of early screening and immediate care in mitigating disease severity. These findings indicate the need to optimize resources for early DR management and to promote screening, even in diabetic individuals with normal vision, to prevent disease progression and reduce visual disability. Further community-based research is needed to achieve a robust, practical understanding of the preventable causes of VI, guide national eye health policies, and enhance long-term patient outcomes.