Central retinal vein occlusion (CRVO) is a common retinal vascular disease.Intravitreal injection of ranibizumab, a vascular endothelial growth factor (VEGF) antibody, is being a useful approach to the treatment of macular edema secondary to CRVO.However, little literature about choroidal thickness variations following intravitreal injection of ranibizumab for CRVO is published up to now.

This study was to observe the dynamic changes of macular choroidal thickness after intravitreal injection of ranibizumab in CRVO eyes.

A self-controlled series cases study was designed.Thirty-one eyes of 31 CRVO patients were included in Tianjin Eye Hospital from June 2013 to November 2014, with the males 19 and females 12 and mean age of (51.13±16.65) years.Ranibizumab (5 mg, 5 ml) was intravitreally injected in the CRVO eyes once per month for 3 times by the same operator.A enhanced depth image (EDI) mode of spectral-domain OCT system was employed to measure the choroidal thickness at subfoveal, 1 mm from fovea nasal and 1 mm from fovea temporal before and 1 month, 2, 3 months after first injection in both CRVO eyes and contralateral healthy eyes, respectively.The best LogMAR vision was recored.This research protocol was approved by the Ethic Committee of this hospital, and written informed consent was obtained from each individual prior to any medical examination.

Retinal bleeding was exhibited in the CRVO eyes in color photography, and fundus fluorescein angiography showed the fluorescine leakege in the early phase and fluorescine accummulation in the late phase.The mean choroidal theckness value was (325.32±83.04), (294.83±80.61), (315.95±90.77) and (314.81±84.98)μm before injection and 1, 2, 3 months after injection, respectively, showing a significantly difference among various time points (F=7.96, P=0.00), and the choroidal theckness values were evidently reduced in various time points after injection in comparison with before injection (P=0.01, 0.01, 0.00). The choroidal thickness value at foveal was (314.81±84.98)μm in the CRVO eyes 3 months after injection, and that in the fellow eyes was (260.47±55.90), with significant difference between them (t=2.95, P=0.01). The LogMAR vision was 0.17±0.09, 0.37±0.23, 0.42±0.26 and 0.49±0.21 before and 1, 2, 3 months after injection, with the significant difference among various time points(F=21.50, P=0.00) and showed considerable improvement after intravitreal injection of ranibizumab(all at P<0.01). The mean retinal thickness value was (244.14±23.28)μm in the fellow eyes, and those in 1 month, 2, 3 months after injection were (523.81±147.61), (352.13±166.71), (376.39±209.46) and (369.00±225.61)μm in the CRVO eyes, showing obvious reduce after intravitreal injection, with significant difference among different time points (F=7.09, P<0.01).

Choroidal thickness at macular fovea is obviously increased in CRVO eyes compared with the contralateral healthy eyes.Intravitreal injection of ranibizumab can reduce choroidal thickness and therefore improve vision.EDI OCT is available in the evaluation of dynamic change of choroidal thickness.Macular choroidal thickness could be used as a predictor of CRVO prognosis following intravitreal ranibizumab.

Retinal vein occlusion/therapy; Vascular endothelial growth factor/antagonists &inhibitors; Antibodies, monoclonal, humanized/therapeutic use; Intravitreal injection; Choroid/pathology; Macula/pathology; Tomography, optical coherence