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

Abstract

This prospective study evaluated the accuracy of IOL power calculation using ray tracing and formulas with and without total keratometry in eyes after SMILE.

An update on intraocular lens power calculations in eyes with previous laser refractive surgery

“…They found that the raytracing method (OKULIX) was the most accurate, with 82% of eyes falling within AE 0.5 D of the target spherical equivalent [60 && ]. This aligns with simulated studies by Lazaridis et al [56] and Elotmani et al [57], which also supported the accuracy of raytracing. Simulated studies by Luft et al [55] and Zhu et al [58] suggested that both the Masket and Barrett True-K formulas were also reasonable choices.…”

“…The available literature on IOL power calculations in post-SMILE eyes is limited. It consists of four retrospective theoretical simulated studies [55][56][57][58], a case report [59], and a recent study based on real data, but with only 11 post-SMILE eyes [60 && ] (Table 4). The findings from these studies are summarized in Table 5.…”

Cataract surgery after corneal refractive surgery: preoperative considerations and management

“…Incorporation of total keratometry has been shown to enhance the IOL prediction accuracy of existing formulas (with no clinical history), including Barrett True-K, Haigis, Shammas-PL, EVO, Holladay, and SRK/T formulas, in eyes with previous myopic LASIK/PRK [29]. Elotmani et al [32 ▪▪ ] compared the performance of various modern IOL calculation formulas, with and without total keratometry, and ray tracing in patients with previous myopic SMILE. Ray tracing (79%) was shown to achieve the highest percentage of eyes within ± 0.…”

Intraocular lens power calculation using total keratometry and ray tracing in eyes with previous small incision lenticule extraction – A case series

“… 4 The residual body of evidence on post-SMILE IOL power calculation is limited by its purely theoretical approach as these reports do not include results from actually performed cataract surgeries. 5 , 6 , 7 In the foreseeable future, the number of patients with prior SMILE treatment requiring cataract surgery is expected to increase exponentially in light of the rising popularity of the SMILE technique as well as demographic developments. Inevitably, ophthalmologists will be challenged by accurate IOL power calculations for these patients.…”

“… 8 , 9 The use of TK-based IOL power calculation has been proven to be beneficial not only in eyes with untreated corneas 10 , 11 but particularly in eyes that have undergone previous myopic excimer-based keratorefractive surgery. 6 , 10 , 12 , 13 In addition to these empirical formulae, the physical ray tracing approach, which does not require any prior clinical history, has also shown excellent outcomes in IOL power calculation for untreated 14 and post-keratorefractive surgery eyes, 15 , 16 , 17 , 18 including a previous report of our group on post-SMILE eyes undergoing cataract surgery. 4 …”