Author: Mohamed Foued Rmili
Co-authors: Rahma Saidane, Racem Choura, Dhouha Gouider, El Ouafi Bouazzaoui, Afef Maalej, Asma Khallouli
Abstract
PurposeTo study the involvement of four mutations: G1691A of factor V, G20210A of prothrombin, C677T and A1298C of methylenetetrahydrofolate reductase in retinal vein occlusions (RVO).
Methods
Our prospective study included 40 patients with RVO and 40 controls. Patients and controls were selected consecutively from the Department of Ophthalmology. Each patient underwent a complete ophthalmologic examination. The diagnosis of RVO was confirmed by fluorescein angiography and was further classified as Central retinal vein occlusion (CRVO), hemispheric retinal vein occlusion (HRVO), or branch retinal vein occlusion (BRVO) according to the site of occlusion. Baseline medical and ocular data were recorded for each patient. Particular attention was given to risk The prevalence of mutations was compared in the 2 groups, taking into account age and cardiovascular risk factors.risk factors. The genotyping was performed by polymerase chain reaction–restriction fragment length polymorphism after receiving informed consent
Results
In the study, HRVO was found in one patient, CRVO in ten patients, and BRVO was observed in 29 patients. The mean ages at disease onset for the 2 case groups (BRVO and CRVO patients) were 49.48 ±17.69 years and 51.5±18.48 years, respectively. The heterozygous G1691A mutation was found in 45% of patients (53% of BRVO and 38% of CRVO) and 5% of controls (OR=16.9; P<0.000001). The G20210A heterozygous mutation was identified in 20% of patients and 3% of controls (OR=8.3; P=0.002). The C677T heterozygous mutation was observed in 67.5% of cases and 49.9% of controls (OR=3.2; P=0.0003). The 1298C mutated allele was observed in 13.8% of patients and 3.2% of controls (OR=4.8; P=0.001). The G20210A mutation was more frequent in patients younger than 50 years old (P=0.02). The G1691A, G20210A, and C677T mutations were more frequent in patients without cardiovascular risk factors. Ischemic venous occlusions were more frequent in patients with at least one cardiovascular risk factor (P=0.189), the G1691A mutation (P=0.35), and the A1298C mutation (P=0.766). The risk of neovascularization was greater in patients with the G20210A (P=0.05), G1691A (P=0.18) and A1298C (P=0,25).
Conclusion
The pathogenesis of RVO is multifactorial.The etiopathogenic role of thrombophilic genetic mutations is a matter of controversy. According to our work, closer monitoring of patients with RVO with cardiovascular risk factors or thrombophilic genetic mutations including G1691A of factor V, G20210A of factor II, C677T and A1298C of MTHFR is necessary for the early detection of neovascularization. Large study would be required to understand completely the contribution of these markers in the risk of all types of RVO.
Financial Disclosure: No.