Comparison of Clinical Outcomes Between Implantable Collamer Lens Implantation and Photorefractive Keratectomy for Myopic Regression After Laser Vision Correction

Background : Myopic regression is a common complication after laser vision correction (LVC). While photorefractive keratectomy (PRK) and implantable collamer lens (ICL) implantation are considered effective retreatment options with favorable outcomes, no direct comparative study has evaluated these two modalities for treating regression. Therefore, we aimed to compare the clinical outcomes and astigmatic correction patterns of ICL implantation and PRK in patients with myopic regression after LVC. Methods : This retrospective study compared 30 eyes treated with ICL implantation and 24 eyes with transepithelial PRK as retreatment for myopic regression after prior LVC. Clinical outcomes, including visual acuity, refractive stability, and vector analysis of astigmatic correction, were evaluated over a 6-month follow-up period. Results : At 6 months, 100% of eyes in the ICL group and 92% in the PRK group achieved a postoperative spherical equivalent (SE) within ±1.00 D, with uncorrected distance visual acuity (UDVA) of 20/20 or better observed in 100% and 96% of eyes, respectively. The ICL group showed faster early visual recovery with significantly better UDVA at 1 week and 1 month ( P < 0.001 and P = 0.005), although long-term outcomes at 6 months were comparable between the groups. The ICL group exhibited superior refractive stability, with no significant change in SE over 6 months ( P = 0.095), whereas the PRK group showed a significant change ( P = 0.040). Vector analysis revealed a tendency toward undercorrection in the ICL group (mean correction index: 0.80 ± 0.45) and overcorrection in the PRK group (1.09 ± 0.55), with the PRK group showing significantly greater surgically induced astigmatism ( P = 0.045). No vision-threatening complications occurred in either group. Conclusions : Both ICL implantation and PRK are safe and effective retreatment options for myopic regression after LVC. ICL demonstrated faster early visual recovery and greater refractive stability, while PRK showed higher astigmatic correction with a trend toward overcorrection.