Refractive and corneal analyses after custom-Q versus wavefront-optimized ablation in photorefractive keratectomy for myopia.

Abstract

PurposeTo evaluate refractive and tomographical outcomes following Custom-Q without Q-adjustment and wavefront-optimized (WFO) photorefractive keratectomy (PRK) for myopia.MethodsThis retrospective, comparative study included 46 eyes in the Custom-Q group and 40 eyes in the WFO group who underwent PRK for myopia and/or myopic astigmatism. Planned central ablation depth (CAD), total laser pulses (from WaveLight EX500), and corneal thickness (CT) changes at central, paracentral (3.0 mm), and mid-peripheral (6.0 mm) zones (from Sirius tomography) were recorded with visual, refractive, and topographic outcomes preoperatively and at 6 months.ResultsPostoperative sphere was closer to emmetropia in the Custom-Q group (0.041 ± 0.17 D vs. -0.089 ± 0.30 D, p = 0.024), and postoperative flat keratometry was lower than in the WFO group (p = 0.045). For 1.00 D spherical equivalent (SE) correction, Custom-Q resulted in lower planned CAD, less CT change across all zones, and fewer laser pulses than WFO (p < 0.05 for all). Both groups showed comparable safety and efficacy indexes (>1.0), similar significant oblate shift, increased root-mean-square of higher-order aberrations6mm (RMS-HOAs6mm), with no significant change in HOAs3mm (p > 0.05 for all), while spherical aberration6mm decreased more in the Custom-Q group (-0.080 ± 0.096 vs. -0.040 ± 0.102, p = 0.024, respectively). There was a significant correlation between preoperative SE and changes in asphericity6mm (r = -0.853, p < 0.001), RMS-HOAs6mm (r = -0.430, p = 0.008), and spherical aberration6mm (r = 0.632, p < 0.001) in the Custom-Q group.ConclusionsCustom-Q without Q-adjustment is an effective and safe option for myopic PRK, achieving better refractive precision and lower CT reduction per diopter than WFO, with improved control of spherical aberration despite comparable increases in asphericity and RMS-HOAs6mm.