AIM: To observe the changes in subfoveal choroidal thickness(SFCT)after intravitreal injections of ranibizumab(IVR)for macular edema secondary to retinal vein occlusion(RVO).

METHODS: Thirty-six eyes of 36 patients with macular edema secondary to RVO)were treated with 0.5mg IVR monthly for 3mo and received additional IVR as needed over the following 1a period. SFCT of the all eyes(the affected eyes with RVO and unaffected fellow eyes)was measured by enhanced depth imaging optical coherence tomography images before and after the IVR.

RESULTS: The mean SFCT of the affected eyes with RVO decreased from 246.7±115.0μm at baseline to 220.5±102.0μm at 1mo(P<0.05), 198.3± 114.0μm at 6mo(P<0.01), 212.6± 96.0μm at 12mo(P<0.01). Whereas the fellow eyes changed from 229.4±108.0μm at baseline to 226.3±107.0μm at 1mo(P>0.05), 228.6±127.0μm at 6mo(P>0.05), 223.6±101.0μm at 12mo(P>0.05). There were statistically significant difference between affected eyes with RVO and unaffected fellow eyes.

CONCLUSION: The SFCT is decreased after IVR for macular edema secondary to RVO. IVR seems to affect the hemorheology of the choroid.