97th DOG Annual Meeting 1999
RETINAL VEIN OCCLUSION ASSOCIATED WITH HOMOZYGOUS METHYLENETETRAHYDROFOLAT POINT MUTATION ( C677T )
A. Andresen, B. Engels, R.A. Widder, P.Walter
Hyperhomocystinemia is recently discussed to be a predisposing factor in developing thromboembolic complications. Mild hyperhomocystinemia is mainly caused by homozygous C677T mutation in the encoding Methylenetetrahydrofolatreductase gen. The prevalence in the western world has been reported to be present in 5-18 %.
Case Report: A healthy 29-year old man developed severe neovascular glaucoma due to ischemic central retinal vein occlusion in the LE. Five months after initial diagnosis the patient had been referred to our department, because of branch retinal occlusion of the RE. At examination the visual acuity was 0.6 on the RE and no light perception on the LE. The intraocular pressure was normal. Because of ischemic areas disclosed in by fluorescein angiography focal lasercoagulation was performed in the RE. Additional treatment was performed with 150 mg fluocortolone and 100 mg acetylsalicylacid. Temporarily visual acuity increases up to 1.0. In the LE the patient was operated on with vitrectomy and siliconoil filling because of tractional retinal detachement. Extensive haematologic, internal medicinal and apparative diagnostics were all unconspicuous. Fasting serum homocystine level, however, shows 38 µ mol/l (5-15 µmol/l normal-range). Moleculargenetic analysis revealed homozygous C677T- mutation. Supplementation of folic acid (10 mg/d) and pyridoxine (250 mg/d) was started.One year after initial presentation visual acuity remained 1.0 in the RE. Serum homocystine level was in normal range.
Conclusion: Retinal vein occlusion in otherwise healthy young persons and no risk factors, screening for hyperhomocystinemia seems to be important, because hyperhomocystinemia is discussed as a new risk factorfor vascular occlusive diseases. Supplementation of Folic acid and Pyridoxin normalizes homocystein level and is strongly recommended.
Dep. of Ophthalmology, University of Cologne, D-50924 Cologne