Association Between Serum Vitamin D Levels and Retinal Vascular Occlusion: A Systematic Review and Meta-Analysis

Area of Science:

• Ophthalmology
• Endocrinology
• Nutritional Science

Background:

• Retinal vascular occlusion (RVO) incidence shows seasonal variations, with higher rates in winter.
• Emerging evidence suggests a connection between vitamin D deficiency and RVO.
• Vitamin D plays a crucial role in vascular health and immune function.

Purpose of the Study:

• To conduct a meta-analysis evaluating the association between vitamin D levels and RVO.
• To determine if vitamin D deficiency is a significant risk factor for RVO.
• To compare vitamin D levels in different subtypes of RVO.

Main Methods:

• Comprehensive literature search of MEDLINE and EMBASE databases (inception to February 2024).
• Inclusion of observational studies comparing serum 25-hydroxyvitamin D (25(OH)D) levels in adult RVO patients versus non-RVO controls.
• Statistical analysis using random-effects model and generic inverse variance method to calculate pooled mean difference (MD) and odds ratio (OR) with 95% confidence intervals (CI).

Main Results:

• Five studies with 528 participants (228 RVO, 300 controls) were included.
• Significantly lower serum 25(OH)D levels were observed in RVO patients (pooled MD: -9.65; 95% CI: -13.72 to -5.59).
• Vitamin D deficiency (serum 25(OH)D < 20 ng/mL) was strongly associated with RVO (pooled OR: 14.52; 95% CI: 1.72 to 122.59).

Conclusions:

• Serum vitamin D levels are significantly lower in patients with RVO compared to controls.
• Vitamin D deficiency represents a potential risk factor for RVO.
• Clinicians should consider screening RVO patients for vitamin D deficiency; further research on supplementation is warranted.