An investigation of changes in ocular blood flow in rabbits with long-term hyperhomocysteinemia using color doppler ultrasonography

Authors: FİGEN NARİN, ABDULHAKİM COŞKUN, NAZMİ NARİN, ALİ BAYKAN, SERTAÇ HANEDAN ONAN, ABDULKERİM COŞKUN, MUAMMER HAKAN POYRAZOĞLU, RUŞEN EREZ

Abstract: Hyperhomocysteinemia was induced in rabbits using methionine. Ocular blood flow changes were examined by color Doppler ultrasonography (CDU). Materials and methods: Fifty New Zealand rabbits were divided into 5 groups. Groups 1-4 received one of the following chemicals: methionine only, methionine plus vitamin B6, methionine plus vitamin B12, or methionine plus folic acid. Controls received no chemicals. Serum homocysteine levels were measured on treatment days 1 and 60. Orbital vessels were examined by CDU on day 60. Results: In the 4 study groups, homocysteine levels were significantly elevated on day 60 compared to the levels on day 1 (P < 0.05). Elevations of homocysteine levels in group 1 were greater than those of groups 2 and 4 on day 60 (P < 0.05). When results of ocular blood flow changes were compared, no statistically significant difference was found based on flow velocities in the ophthalmic artery. Measurements from the ciliary artery revealed a statistically significant decrease in flow velocity in the study groups (P < 0.05). Conclusion: Using CDU, we found that flow velocities in the ciliary artery were decreased. This condition is attributed to atherosclerotic and thromboembolic alterations of the ocular vessels due to hyperhomocysteinemia.

Keywords: Homocysteine, atherosclerosis, vitamins, rabbit, color doppler ultrasonography

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