Sir,

The letter ‘Local safety of repeated intravitreal Ozurdex’ by Hernández-Martinez et al1 highlights the impact of intravitreal Dexamethason-implant (Ozurdex) on lens opacification. They showed in a retrospective review that four out of five (BRVO) or six (CRVO) eyes receiving a second Ozurdex showed a progression of cataract requiring surgery. As the Geneva study has shown,2 Ozurdex is an effective treatment option for macular edema due to RVO. While our study3 confirms these data, it furthermore shows a significant progression in cataract formation after the third intravitreal injection. Therefore, it is mandatory to consider along with age and intraocular pressure the lens status when using intravitreal Ozurdex. In the mentioned retrospective case series by Hernández-Martinez et al, it is not clear whether there is a progression of an existing cataract to a cataract requiring surgery or clear lenses showing a beginning of cataract formation. Furthermore, no objective classification of lens opacification was assessed to show which kind of lens opacification shows a significant progression requiring surgery. It is also necessary to investigate recurrence rates, treatment intervals and the data should be supplemented by a clear follow-up time. We agree that long-term follow-up data are needed to confirm present observations. As the adequate treatment of macular edema due to RVO is still a challenge, treatment possibilities including intravitreal steroids, anti-VEGF substances, laser photocoagulation or combinations are safe and effective options after taking into account the pathogenesis of retinal vein occlusion.