Impact of cataract surgery on patients receiving intravitreal therapy for retinal vein occlusion

Background To assess clinical outcomes of cataract surgery in eyes treated with intravitreal injections for cystoid macular oedema (CMO) secondary to retinal vein occlusions (RVOs). Methods Eyes receiving intravitreal injections for CMO secondary to RVOs that underwent cataract extraction were identified from the Fight Retinal Blindness! Registry and matched 1:1 by 9 parameters with phakic controls also receiving intravitreal injections for the same condition. VA change at 12 months, central subfield thickness (CST) and injection frequency before and after surgery were compared between the two groups. The effect of baseline features on the final VA including age, CST, treatment frequency among others was tested. Results We included 193 eyes that had cataract extraction (exposed) matched with 193 phakic eyes that did not have surgery (matched). VA (95%CI) changed by +9.9 (7, 12.8) letters in exposed eyes versus −2.4 (−4.1, −0.7) letters in matched eyes (p < 0.01). The mean [SD] VA at 12 months was similar in exposed and matched eyes [60.7 (23.0) vs. 61.1 (24.3) letters, respectively, p = 0.81]. The mean [SD] CST was similar between groups before and at surgery, but it was greater in exposed compared with matched eyes [353 (152) vs. 322 (123) μm, respectively, p = 0.03] 12 months after surgery. Exposed eyes received more injections [median (range)] than matched eyes during the 12 months after surgery [5 (3, 7) vs. 4 (1, 6), injections, p < 0.01]. Conclusions Cataract extraction delivered good visual outcomes in patients treated for CMO secondary to RVOs. More injections were required on average in the 12 months after surgery in eyes undergoing surgery compared to matched controls.