Iol Performance And Accuracy Of Formulas For Iol Calculation In Post-Myopic Laser Refractive Corneal Surgery Implanted With A Spiral Iol

To identify the visual performance and accuracy of formulas for intraocular lens (IOL) power calculation in post–myopic laser refractive corneal surgery following implantation of a spiral intraocular lens (Galaxy RayOne, Rayner)

Single private center real-world study conducted at Guatemala City, in patients post–myopic laser refractive corneal surgery undergoing cataract surgery with implantation of presbyopia-correcting spiral intraocular lenses. A single surgeon performed the surgeries using phacoemulsification technique. No intraoperative or postoperative complications were reported.

Six eyes undergoing cataract surgery with spiral IOL implantation who had prior post–myopic laser refractive corneal surgery were retrospectively analyzed. Monocular UDVA (4 m), UIVA (66 cm), and UNVA (40 cm) were measured at 3 months using ETDRS charts and low contrast charts for UIVA and UNVA. Preoperative corneal parameters (SIMK, tHOAs, coma/trefoil, Z40, pupil size) were assessed using Scheimpflug tomography. ACD, AXL, LT, and WTW were assessed using optical biometer IOLMaster 700. Refractive outcomes of 5 formulas (EVO, Barrett True K, Hoffer-QST, PEARL, and Panacea) were evaluated. Accuracy was defined as the difference between the measured and predicted postoperative refractive spherical equivalent using the IOL power implanted.

6 eyes (mean AXL: 25.84 ±1.3mm) mean monocular VA and spherical equivalent pre vs post-surgery improved statistically significant (p<0.005). Preop UDVA 0.54 ±0.41 vs postop 0.09 ±0.01 logMAR, UIVA preop 0.45 ±0.07 vs postop 0.00 ±0.01 logMAR and UNVA preop 0.59 ±0.22 vs postop 0.02 ±0.04 logMAR. At contrast sensitivity chart UIVA (from 0.73 ±0.21 to postop 0.20 ±0.06 logMAR) and UNVA (from 0.68 ±0.11 vs postop 0.15 ±0.03 logMAR) improved significantly  (p<0.005). Mean tHOAs, SA (6mm) and Q were (0.19 ±0.09µm, 0.35 ±0.25µm, 0.22 ±0.29, respectively). PEARL-DGS resulted in a mean prediction difference of -0.13 ±0.25D. Other formulas in order of magnitude were -0.37, -0.50, -0.80, -0.87D for the EVO, Barrett TK, Hoffer-QST and Panacea, resp.

The spiral IOL demonstrated stable visual performance in patients after cataract surgery in post–myopic laser refractive corneal surgery eyes with high values of SA and showed to be safe. Visual acuity for all distances and contrast sensitivity significantly improved. Patients were without symptoms of halos, dysphotopsia or poor night vision. Currently, the patients do not require corrective lenses suggesting that the IOL tolerates well a small residual myopia. In comparison to other IOL formulas, the PEARL formula resulted in better refractive outcomes. We suggest that PEARL, EVO and Barrett True K be considered as the first choices for IOL power calculation in these eyes choosing the first positive IOL option.