The results of this review suggest that phakic IOLs are safer than excimer laser surgical correction for moderate to high myopia in the range of -6.0 to -20.0 D and phakic IOLs are preferred by patients. While phakic IOLs might be accepted clinical practice for higher levels of myopia (greater than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism), it may be worth considering phakic IOL treatment over excimer laser correction for more moderate levels of myopia (less than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism). Further RCTs adequately powered for subgroup analysis are necessary to further elucidate the ideal range of myopia for phakic IOLs.
Randomized prospective comparison of visian toric implantable collamer lens and conventional photorefractive keratectomy for moderate to high myopic astigmatism.
To compare the Visian Toric Implantable Collamer Lens (TICL), a toric phakic intraocular lens (IOL), and photorefractive keratectomy (PRK) in the correction of moderate to high myopic astigmatism.
                This prospective, randomized study consisted of 43 eyes implanted with the TICL (20 bilateral cases) and 45 eyes receiving PRK with mitomycin C (22 bilateral cases) with moderate to high myopia (-6.00 to -20.00 diopters [D] sphere) measured at the spectacle plane and 1.00 to 4.00 D of astigmatism. All patient treatment and follow-up occurred at the Naval Medical Center San Diego. Study follow-up was 1 day, 1 week, 1, 3, 6, and 12 months postoperative.
                Mean best spectacle-corrected visual acuity (BSCVA), change in BSCVA, proportion of cases with improvement of 1 or more lines of BSCVA, proportion of cases with BSCVA and uncorrected visual acuity (UCVA) 20/12.5 or better, proportion of cases with BSCVA and UCVA 20/16 or better (6 months, 88% vs 54%, P=.002), and predictability +/-1.00 D (6 months, 100% vs 67%, P<.001) were all significantly better in the TICL group than the PRK group at all time periods studied postoperatively. Similarly, contrast sensitivity, tested at both the 5% photopic level and the 25% mesopic level, was significantly better at all postoperative time points in the TICL group. Mean spherical equivalent refraction was closer to emmetropia (0.28+/-0.41 vs 0.76+/-0.86, P=.005), and predictability +/-0.50 D and stability of manifest refraction (+/-0.50 D and +/-1.00 D) were significantly better in the TICL group at all postoperative visits through 6 months. Mean astigmatism correction at 6 months was not significantly different between the two groups (0.52+/-0.33 vs 0.46+/-0.35, P=.450).
                The TICL performed better than PRK in all measures of safety (BSCVA), efficacy (UCVA), predictability, and stability in this comparison, supporting the TICL as a viable alternative to existing refractive surgical treatments.