IOL Power Calculations and Cataract Surgery in Eyes with Previous Small Incision Lenticule Extraction

Abstract

Small incision lenticule extraction (SMILE), with over 5 million procedures globally performed, will challenge ophthalmologists in the foreseeable future with accurate intraocular lens power calculations in an ageing population. After more than one decade since the introduction of SMILE, only one case report of cataract surgery with IOL implantation after SMILE is present in the peer-reviewed literature. Hence, the scope of the present multicenter study was to compare the IOL power calculation accuracy in post-SMILE eyes between ray tracing and a range of empirically optimized formulae available in the ASCRS post-keratorefractive surgery IOL power online calculator. In our study of 11 post-SMILE eyes undergoing cataract surgery, ray tracing showed the smallest mean absolute error (0.40 D) and yielded the largest percentage of eyes within ±0.50/±1.00 D (82/91%). The next best conventional formula was the Potvin–Hill formula with a mean absolute error of 0.66 D and an ±0.50/±1.00 D accuracy of 45 and 73%, respectively. Analyzing this first cohort of post-SMILE eyes undergoing cataract surgery and IOL implantation, ray tracing showed superior predictability in IOL power calculation over empirically optimized IOL power calculation formulae that were originally intended for use after Excimer-based keratorefractive procedures.

Comparison of intraocular lens power calculation formulas with and without total keratometry and ray tracing in patients with previous myopic SMILE

“…Regarding the variance of the mean PE by ray tracing, the results of Lischke et al yielded a very small variance of 0.23 D 2 . 10 These results were in accordance with our study, yielding a mean PE variance by Okulix of 0.205 D 2 . These results indicate high precision and reliability of ray tracing with Okulix in IOL power calculation after SMILE.…”

“…The high variance of 1.63 D 2 obtained with Haigis-L reported by Lischke et al can be attributed to the small amount of eyes, which is strongly influenced by outliers (range of mean PE ranges from À3.76 to 1.17 D). 10 Lischke et al reported, to the authors' knowledge, for the first time, the results of IOL calculations in pseudophakic eyes after SMILE. 10 Although the number of eyes examined in the study conducted by Lischke et al is very small, these results most likely indicate that Haigis-L is not among the most accurate formulas for IOL calculation after SMILE.…”

“…10 Lischke et al reported, to the authors' knowledge, for the first time, the results of IOL calculations in pseudophakic eyes after SMILE. 10 Although the number of eyes examined in the study conducted by Lischke et al is very small, these results most likely indicate that Haigis-L is not among the most accurate formulas for IOL calculation after SMILE. 10 It is reasonable to assume that the TK-based Haigis formula is significantly more advantageous than the regression-based Haigis-L formula.…”

“…Regarding IOL calculation in eyes with previous SMILE, the literature is very sparse, and only single case reports can be found in the literature. 9,10…”

Cascade reaction triggering and photothermal AuNPs@MIL MOFs doped intraocular lens for enhanced posterior capsular opacification prevention

“…Minor incision cataract surgery can effectively reduce the risk of postoperative intraocular inflammation and is an essential type of cataract surgery [ 39 ]. To meet the demands of minor incision surgery, the materials used to prepare IOLs must have excellent bending, folding, and shape recovery properties.…”