Visian Collamer Phakic Intraocular Lens in High Myopic Asian Eyes

Abstract

To evaluate the safety and efficacy of the Implantable Collamer Lens (Visian), a phakic intraocular lens (PIOL), in the correction of high myopia in Asian eyes. This prospective study comprised 61 eyes in 40 Chinese patients with mean preoperative manifest spherical equivalent refraction of -14.54 +/- 3.61 diopters (D) (range: -7.00 to -24.75 D) who underwent Visian PIOL implantation from May 2002 to December 2004. The anatomical differences between Asian and Caucasian eyes were compared. Mean follow-up was 13.67 +/- 8.51 months (range: 1 to 32 months). Predictability of the manifest spherical equivalent refraction to within +/- 1.00 D was achieved in 88% of eyes and +/- 0.50 D in 72.5% of eyes. The mean postoperative manifest spherical equivalent refraction was -0.10 +/- 0.74 D, with 97% of eyes maintaining or gaining > or = 1 lines of best spectacle-corrected visual acuity (BSCVA). Two eyes lost 1 line of BSCVA. Retinal detachment developed in 1 eye 15 months after initial surgery. Because of the statistical differences in anterior chamber depth and white-to-white distance between Caucasian and Chinese eyes, the Visian PIOL size was more accurate if the calculation was modified so that 0.5 mm was added to the white-to-white measurement if the anterior chamber depth was < or = 3.0 mm and 1.0 mm to the white-to-white measurement if the anterior chamber depth was >3.0 mm. Initial incorrect sizing using the original nomogram led to the only cataract in our series. The implantation of the Visian PIOL for correcting moderate to high myopia in Asian eyes shows similar safety and efficacy to the FDA clinical trial of Caucasian eyes. Proper sizing of the Visian PIOL is important and differs slightly in Asian eyes.