Analysis of genetic polymorphisms related to thrombosis and other risk factors in patients with retinal vein occlusion

Central retinal vein occlusion and thrombophilia

“…In 1998 Salomon et al found, in 102 patients with CRVO, BRVO and hemi-RVO, that homozygosity for the thermolabile MTHFR mutation was present in 25.5% of patients compared to 15.2% of control patients, giving an overall odds ratio of 1.9. 32 Indeed this mutation was along with hypertension and a family history of stroke, independent risk factors for RVO whereas FVL and the prothrombin mutation were not. Similar results were obtained by Loewenstein et al in 59 patients who found a homozygous mutation rate of 18.6% compared to 10.4% in healthy controls (P Ͻ 0.038).…”

“…20 Six studies have investigated the role of APCR/FVL in hemispheric and retinal branch occlusion. 18,25,[30][31][32][33]35 Although patients with this thrombophilic tendency were identified, the incidence compared to the normal population was not increased (in studies where a direct comparison was made).…”

“…17,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Although many studies suggest an increased frequency of APCR/FVL in patients with CRVO only two out of nine studies in which the incidence of APCR/FVL is compared with a normal cohort is there a significantly increased incidence of this abnormality. Surprisingly both of these studies included patients of any age where one would have anticipated an association with younger patients.…”

“…20,32,35,38,39 Between them a total of 232 patients have been assessed but only seven patients with this abnormality were identified-a frequency not dissimilar to that expected in the normal population.…”

Thrombophilic mutations and risk of retinal vein occlusion

“…Recently, a study (31) also suggested that the presence of factor V Leiden increases the risk of neo-vascular complications in patients presenting central RVO. However, despite being the thrombophilic abnormality most frequently associated with RVO, most studies have failed to show a role for this mutation in RVO (17)(18)(19)22,26,32) . In the present study, factor V Leiden was the only mutation with a higher frequency in patients than in controls (3.6% versus 0%).…”