Extended depth of focus lens implantation after radial keratotomy [Response to Letter]

Dear editor

We appreciate the letter by Prof. Srirampur regarding the recent publication of our results of extended depth of focus (EDOF) lens implantation in post-radial keratotomy (RK) patients. Prof. Srirampur brings up a few excellent points. First, we agree completely that one of the major challenges in post-RK eyes is the accurate estimation of corneal power. As noted in the discussion section of our paper, there are a number of ways to avoid overestimation of corneal power in these eyes, including the use of newer-generation formulae and modifiers, such as in the HICSOAP PRO IOL calculation software from Holladay Consulting.¹ It should also be noted that not all eyes included in the study were calculated to a plano target, with 38% percent targeted to some degree of myopia at surgeon discretion. This is common practice in the management of post-RK eyes and may help avoid hyperopic surprise.² It is important to note that this challenge is present regardless of the IOL chosen, and it is not the intent of the paper to suggest the use of an EDOF lens should replace the careful preoperative planning that these eyes necessitate. Rather, our preoperative planning was performed as it is in our practice for any monofocal IOL in this surgical scenario, and it is our recommendation that cataract surgeons similarly use their preferred method of post-RK IOL calculations when considering implantation of an EDOF lens.

Second, as brought up by Prof. Srirampur, we would like to clarify that none of the eyes included in the study had undergone corneal collagen cross-linking (CXL) prior to cataract surgery, nor were any deemed ectatic by clinical or topographic evaluation.