Changes in Anterior Segment Biometric Properties Following Implantation of Posterior Chamber Phakic Intraocular Collamer Lens (ICL): Conventional vs. Aquaport ICL

To compare changes in anterior segment biometric properties after implantation of conventional posterior chamber phakic intraocular collamer lens (ICL) versus Aquaport posterior chamber phakic ICL.
The records of myopic patients who underwent ICL implantation between March 2012 and April 2015 were reviewed. Patients’ demographic data, manifest and cycloplegic refraction, best-corrected visual acuity (BCVA), and intraocular pressure (IOP) were recorded preoperatively. All patients underwent ultrasonic biomicroscopy (UBM; STS, Quantel Medical, France) under dim light conditions to determine anterior segment biometric properties including sulcus-to-sulcus distance and iridocorneal angle parameters. Corneal tomography (Galilei dual Scheimpflug analyzer, Ziemer, Switzerland) was used to obtain corneal curvature and elevation data. The same measurements were obtained postoperatively to determine and compare changes in biometric parameters between two types of ICL.
Overall, 58 eyes of 30 myopic patients were enrolled in this study. Of which, 28 eyes of 15 patients were implanted with V4b ICL and 30 eyes of 15 patients received V4c ICL. The mean follow up time was 27.7 ± 9.3 and 26.6 ± 8.8 months in the V4b and V4c groups, respectively. There was no significant difference in postoperative refraction results and IOP between groups at 1 and 3 postoperative months. Compared to preoperative values, all anterior segment biometric parameters were changed in both groups postoperatively. Nasal angle parameters (TIA, AOD500) were significantly different between the V4b and V4c groups. The two study groups were comparable in other biometric parameters and lens densitometry postoperatively.
The presence of central hole (Aquaport®) in V4c ICL is as effective as performing peripheral iridotomy in V4 ICL lenses in preventing further deterioration of anterior segment biometric parameters and may provide more uniform flow of aqueous humor to the anterior chamber angle.