Aims To investigate the choroidal thickness changes in eyes with retinal vein occlusion (RVO) and to determine the effect of an intravitreal dexamethasone implant (Ozurdex) on choroidal thickness.

Methods This study comprised 47 patients diagnosed with unilateral, RVO-associated macular oedema (MO) and treated with Ozurdex. Baseline subfoveal choroidal thickness (SFCT) and central macular thickness (CMT) of the RVO eyes were compared with those of the normal contralateral eyes; serial changes in this parameter were evaluated at 1, 3 and 5 months after Ozurdex injection. The correlation between SFCT and CMT and between visual acuity change and SFCT or CMT changes were also investigated.

Results The mean SFCT was significantly higher in RVO eyes at baseline (260.3±71.2 μm) than it was in contralateral eyes (217.6±55.3 μm; p<0.001). While the mean SFCT decreased at 1 and 3 months after Ozurdex injection, it slightly increased at month 5. The change in SFCT was significantly associated with the change in CMT at 3 months (r=0.5073; p=0.0006) and 5 months after Ozurdex injection (r=0.3489; p=0.0274). The improvement in visual acuity was significantly correlated with the decrease in SFCT (r=0.3241; p=0.0413).

Conclusions SFCT in eyes with RVO was significantly greater than it was in normal contralateral eyes. After Ozurdex injection, SFCT decreased significantly. Improvement in visual acuity was correlated with the decrease in SFCT after Ozurdex injection.