Correlation of serum 1,25-dihydroxycholecalciferol with the incidence of primary open-angle glaucoma: A cross-sectional study on patients with chronic illnesses

PURPOSE: Primary open-angle glaucoma (POAG) is a clinical progressive neuropathy which can lead to irreversible blindness if left untreated. A low level of serum Vitamin D3 is a major risk factor for glaucoma, and hence, represents a second target for glaucoma therapy following intraocular pressure (IOP). However, there is still controversy about whether there is a direct correlation between Vitamin D3 deficiency and the risk of increased IOP. This study aims to investigate the correlation between low serum levels of 1,24-dihydroxycholecalciferol and the development of open-angle glaucoma. METHODS: The study included a total of forty-one patients with POAG. Patients were classified into whether they have chronic illnesses such as type 2 diabetes and hypertension. Matching control subjects of 20 healthy controls were also included in the study. Anthropometric measures and venous blood samples were taken from all participants for serum analysis of various biochemical markers including serum 1,25-dihydroxycholecalciferol (1,25(OH)2D) levels. RESULTS: Overall, serum Vitamin D3 levels were 15% significantly lower in the patient's cohort with open-angle glaucoma as compared to the healthy participants (P < 0.05). Among those, 63% of type 2 diabetic participants had significantly low levels of Vitamin D3 (P < 0.01). There was also a significant 70% reduction in serum Vitamin D3 levels among the hypertensive participants, (P < 0.001). CONCLUSION: We concluded that lower serum 1,25(OH) 2D levels were significantly associated with an increased risk of open-angle glaucoma in patients with chronic illnesses.