Incidence of cataract following implantation of a posterior-chamber phakic lens ICL (Implantable Collamer Lens) - long-term results.

AIM

To evaluate late postoperative complications, especially cataract occurrence, its morphological type and factors affecting its development in patients implanted with ICL (Implantable Collamer Lens).

METHODS

We analysed the results of ICL implantation in 34 patients (type ICM V4 for myopia, ICH V3 for hyperopia, TICM V4 for astigmatism) in our department between 1998 and 2013. The cohort comprised 62 eyes (40 myopic and 22 hyperopic). Seven eyes with a toric ICL implanted were included in these groups according to spherical equivalent (SE). The average follow-up period was 10.5 ± 3.5 years. We examined uncorrected and best-corrected visual acuity (UCVA and BCVA), SE, ICL vaulting (using anterior segment OCT) and occurrence of late postoperative complications, especially cataract formation in 2 groups of patients - myopes and hyperopes.

RESULTS

Among the most common late postoperative complications were pigment dispersion syndrome in 27 eyes, 43.5% (12 myopic eyes and 15 hyperopic eyes) and cataract formation. Lens opacities, including opacities without loss of BCVA, were observed in 18 eyes (29%). Opacities affecting visual acuity were observed in 10 eyes (16.1%). Cataract significantly affecting visual acuity occurred in 7 eyes, i.e. 11.3% (5 myopic eyes and 2 hyperopic eyes). In these eyes, ICL removal and cataract surgery with implantation of posterior chamber intraocular lens (PC IOL) was performed. The most common morphological type of cataract were anterior subcapsular opacities (83.3%), the average time of onset was 3.4 ± 1.9 years after ICL implantation. We did not prove a statistically significant association either between cataract occurrence and age at the time of surgery, or between cataract occurrence and higher preoperative spherical equivalent. We did not prove a significant association between cataract occurrence and low vault, however in 7 eyes after cataract surgery and ICL removal we do not know the vault values. In one eye uveitis with cystoid macular oedema was observed, in two highly myopic eyes repeated ICL dislocation and cataract occurred. In both of these cases the ICL was removed.

CONCLUSIONS

According to our experience, implantation of ICL in moderate and high ametropia was relatively safe upon assessing the long-term outcomes. Among the most common complications were pigment dispersion syndrome and anterior subcapsular cataract formation. Cataract can be managed effectively surgically with good refractive outcomes without loss of BCVA. However, loss of accommodation after cataract surgery and risk of vitreoretinal complications must be considered.Key words: ICL (Implantable Collamer Lens), posterior chamber phakic intraocular lens, refractive surgery, cataract occurrence.