A year after posterior chamber phakic intraocular lens (PCP-IOL) implantation for correction of myopia, patients can experience significant changes in biometric variables and intraocular lens (IOL) calculation results, according to a study published in the Journal Français d’Ophtalmologie.
To evaluate changes in biometric variables and IOL calculation results after PCP-IOL implantation, the investigators conducted a retrospective, observational study. They included 65 eyes of 38 patients who underwent implantable collamer lens (ICL) implantation for myopia correction between January 2017 and June 2018 and compared biometric variables and IOL calculation results prior to, and at least 1 year after, implantation. An optical coherence tomography (OCT) biometer was used to assess optical biometry, including anterior chamber depth, axial length, flat, steep, mean keratometry values, and IOL calculation results.
Of the 38 patients with a mean age of 28.29 years (range, 21-37, 57.9% women, 42.1% men). The study included both eyes of 27 patients and a single eye of 11 patients. The mean follow-up duration was 14.9 months.
“The question of how PCP-IOL affected the outcomes of IOL power calculation formulas was one of the main concerns in our study,” according to the study authors. “We found statistically significant decreases in the outcomes of IOL calculation formulas; Holladay 2, Hoffer Q, Haigis, and SRK/T postoperatively.”
Significant preoperative to postoperative changes were observed in mean refraction (-9.81 vs -0.27 D; P =.001), mean corrected distance visual acuity (Snellen equivalent; 6/7.98 vs 6/6.33; P =.001), mean anterior chamber depth (3.70 vs 3.34 mm; P =.001), mean axial length (26.61 vs 26.71 mm; P =.001), and mean flat keratometry (42.82 vs 42.73 D; P =.012). The mean IOL power calculations (the Holladay2, Hoffer Q, Haigis, and SRK/T formulas) demonstrated decreases with all formulas, ranging from 0.19 D to 0.30 D, after PCP-IOL implantation. No intraoperative or postoperative complications were observed.
The primary limitation of the study was its retrospective design.
Kayhan B, Coskunseven E. Changes of ocular biometry in eyes with posterior chamber phakic intraocular lens implantation. J Fr Ophtalmol. Published online January 26, 2022. doi:10.1016/j.jfo.2021.10.006