Evaluation of Visual Outcome of 2 Phakic Posterior Chamber Implantable Lenses in High Myopia: A Comparative Study

Purpose: To evaluate and compare the visual outcomes of two phakic intraocular lenses in high myopia. Methods: A prospective comparative study was undertaken on 50 eyes of 26 patients {age >= 21 years and divided into two groups (implantable collamer lens [ICL] V4c, n=25 eyes and refractive implantable lens [RIL], n=25 eyes)}. Patients were evaluated for uncorrected distance visual acuity (UCVA), best-corrected distance visual acuity, manifest refractive spherical equivalent (MRSE), contrast sensitivity, intraocular pressure, dilated fundus examination, trabecular-iris angle (TIA), anterior chamber depth, horizontal white-to-white diameter, wavefront aberrometry, and endothelial cell (EC) count. All patients were followed up until 6 months and additionally evaluated for anterior chamber inflammation, cataract, and lens vault. Results: The baseline parameters (UCVA, MRSE, and EC count) and postoperative improvement in UCVA, contrast sensitivity, MRSE, EC loss, safety index, and efficacy index were comparable between both the lenses. The improvement in aberrometric profile was significantly better in the ICL group. The mean postoperative vault was higher in RIL group (434.88 +/- 162.48 mu m vs. 547.24 +/- 159.83 mu m, P=0.0173); however, the vault was within normal range in both the groups. The decrease in mean TIA was significantly higher in RIL group (8.58 vs. 13.45 mu m, P=0.0073). Conclusion: Acrylic phakic lens can be considered as a suitable alternative to collamer lens for refractive correction of high myopia. The collamer lenses showed slight superiority in some qualitative visual parameters; however, collamer lenses do not present with subjective complaints in the patients.