Clinical study of the CACHET phakic intraocular lens for the correction of high myopia

Abstract

Objective To evaluate the efficacy, safety, stability and predictability of the AcrySof® CACHETTM phakic intraocular lens (PIOL) for the correction of high myopia. Methods In this prospective study, 12 patients (22 eyes) who ranged in age from 19 to 40 with high myopia at -17.25~-6.50 (-11.97±3.03) diopters (D) were implanted with angle-supported phakic intraocular lenses from 2012 January to 2013 February. Visual acuity, refraction, intraocular pressure, corneal endothelium, PIOL position, contrast sensitivity, glare sensitivity, surgical complications and poor visual symptoms were assessed preoperatively and 1 day, 1 month, 3 months, 6 months and 1 year after treatment. The repeated measures ANOVA was used for statistical analysis. Results The mean manifest refraction at the one-year follow-up was within 1D of the attempted correction in 22/22 eyes and 20/22 eyes were within 0.5 D of the attempted correction. At 1 day, 1 month, 3 months, 6 months and 1 year postoperatively, the mean safety indexes were 1.31, 1.36, 1.34, 1.41, 1.31 and the mean efficacy index was 1.23, 1.28, 1.22, 1.23, 1.31. The differences in near vision and intraocular pressure were not statistically significant at any time point. The mean loss of corneal endothelium was 1.69%±2.2%, 2.25%±3.15%, 4.32%±3.04%, 4.27%±3.52%, 3.82%±2.15% at 1 day, 1 month, 3 months, 6 months and 1 year postoperatively. The distance from the central and peripheral corneal epithelium to the AcrySof® CACHETTM phakic IOL was 1.96±0.25 mm (>1.5 mm) and 1.36±0.22 mm (>1.0 mm), and was 0.99±0.08 mm (>0.8 mm) and 0.94±0.09 (>0.8 mm) from the AcrySof® CACHETTM phakic IOL to the natural lens. An analysis of the results of the steadiness of the PIOL showed that it was stable in 11/22 but 6/22 had a clockwise rotation and 5/22 had a counter-clockwise rotation. Improvements were statistically significant when contrast sensitivity and glare sensitivity were compared preoperatively and postoperatively. The study showed that there was a high degree of satisfaction among patients. Conclusion AcrySof ® CACHETTM phakic IOL implantation for the correction of high myopia is effective, safe and predictable. It can be a supplement to corneal refractive surgery but follow-up is still required to evaluate the long-term results. Key words: Phakic intraocular lenses; Myopia, degenerative; AcrySof ® CACHETTM phakic intraocular lenses