Phakic IOLs for Myopia and Myopic Astigmatism
American Journal of Ophthalmology, October 2019
Long-term data on the visual outcomes of implantable collamer lenses (ICLs) are minimal. Nakamura et al. conducted a 10-year retrospective study of patients who received Visian implantable collamer lenses to treat moderate to high myopia, with or without astigmatism. The authors found that ICL implantation produced good long-term outcomes for safety and efficacy as well as for predictability and stability.
For this observational case series, the researchers included 114 eyes (61 patients) that underwent ICL placement to correct myopia or myopic astigmatism. At the time of surgery, the patients were between the ages of 20 and 50.
The authors collected data from the pre-op visit and from follow-up visits that extended until 10 years following surgery. Safety and efficacy indices were calculated from corrected and uncorrected distance visual acuity (VA) using these equations: post-op CDVA/pre-op CDVA and post-op UDVA/pre-op CDVA, respectively.
The researchers implanted toric ICLs in 72 eyes and spheric ICLs in 42 eyes. At the 10-year mark, 70 eyes (38 patients) were examined. Of these, 71.4% were within 0.5 D of the attempted spherical equivalent correction, and 87.1% were within 1.0 D. The mean logMAR results were −0.01 ± 0.24 (UDVA) and −0.18 ± 0.07 (CDVA). The mean safety index was 0.88 ± 0.15, and the mean efficacy index was 0.66 ± 0.26. The intraocular pressure was unchanged during the observation period, and eyes lost an average of 5.3% ± 12.3% of their pre-op endothelial cell density.
Adverse events included anterior subcapsular cataract in 12 of the 114 eyes; four of these required ICL explantation and phacoemulsification. As cataract formation after ICL surgery is concerning, the authors emphasized that risk factors for this complication should be explored further.
Given these results, it appears that good 10-year outcomes are likely for eyes with myopia or myopic astigmatism that receive implantable toric or spheric ICLs. Knowledge of the longer-term postoperative course is crucial, the authors said.
The original article can be found here.