97th DOG Annual Meeting 1999
GENETIC THROMBOPHILIA IN RETINAL ARTERIAL AND VENOUS OCCLUSION
K. Greiner, G. Hafner, D. Peetz, W. Prellwitz, N. Pfeiffer
Whereas an increased prevalence of resistance to activated protein C (APCR) has been found in patients with deep vein thrombosis (DVT), only a few studies on its prevalence in patients with retinal venous occlusion exist. We therefore investigated the prevalence of genetic defects associated with thrombophilia in patients with retinal vascular occlusion.
Patients and Methods: In a prospective study, 76 patients with retinal vascular occlusion (central retinal vein occlusion (CRVO) n=35, branch retinal vein occlusion (BRVO) n=21, central retinal artery occlusion (CRAO) n=13, branch retinal artery occlusion (BRAO) n=7) were screened for coagulation disorders and vascular disease risk factors. Testing for genetic APCR and the prothrombin gene mutation (20210 G/A) was done with a PCR method. Protein C and S were determined with functional tests. We also investigated a control group of 209 patients with DVT. The chi2 test was used for statistical analysis.
Results: We found APCR in 10 (28,6%) of 35 patients with CRVO and 4 (19,1%) of 21 patients with BRVO. There was only one patient with APCR in the CRAO group and two in the BRAO group. The APCR prevalence in the CRVO group was significantly higher as compared to the expected 8.8% prevalence of the R506Q mutation in the normal population. Comparing the APCR prevalence in the BRVO, CRAO and BRAO group to the normal population, the difference was not statistically significant. APCR prevalences in CRVO patients and patients with DVT (40/209=19.1%) did not significantly differ. 16 of 17 patients with retinal vascular occlusion and APCR were heterozygous for the R506Q mutation. One patient was homozygous. We found no protein C or S deficiency, nor the prothrombin gene mutation.
Conclusions: There is a high APCR prevalence in patients with CRVO which is compatible to that in DVT patients. APCR should be looked for in all patients with CRVO.
Department of Ophthalmology, Mainz University Hospital