Comparison of Nd : YAG capsulotomy rates following phacoemulsification with implantation of PMMA, silicone, or acrylic intra-ocular lenses in four European countries.

PURPOSE: The aim of this study was to compare the incidence of Nd : YAG laser capsulotomy after cataract surgery according to the type of intra-ocular lens material (PMMA, silicone, hydrophilic acrylic, hydrophobic acrylic) implanted in four European countries (France, Italy, Germany, Spain). DESIGN: A retrospective record review. PARTICIPANTS: A review of 1525 patients (first operated eye), aged 50 to 80 years, operated on for cataract in 1996 or 1997 in 16 surgical centers (4 per country). METHODS: The study employed a retrospective cohort design. Charts were reviewed to collect information during at least a three-year period following cataract surgery to identify patients who underwent Nd : YAG laser capsulotomy postoperatively. MAIN OUTCOME MEASURES: Data on the type of intra-ocular lens implanted was extracted from the patient notes, as was the date and outcome of the Nd : YAG laser intervention. Kaplan-Meier survival curve analysis with the time to Nd : YAG laser was performed on the data. RESULTS A total of 1525 patients (first operated eye) were available for the study (n = 294 for hydrophilic acrylic, n = 384 for PMMA, n = 421 for hydrophobic acrylic, n = 426 for silicone). There was a highly statistically significant difference between the IOL groups for the incidence of posterior capsule opacification (p < 0.001) and for Nd : YAG laser treatment (p < 0.001). The mean delay of Nd : YAG laser treatment from the date of cataract operation was 2.48 years (+/-1.70, ranging from 0 to 5.88 years). The rate of Nd : YAG laser capsulotomy over the follow-up period was lowest in the hydrophobic acrylic group (7.1%), followed by silicone (16.2%), PMMA (19.3%) and hydrophilic acrylic (31.1%), respectively. CONCLUSIONS: A low incidence of posterior capsular opacification (PCO) and Nd : YAG laser treatment was detected in hydrophobic acrylic IOLs in comparison to three other types of IOLs implanted in a large cohort of persons with age-related cataract. Choice of IOL type may reduce the need for Nd : YAG laser treatment, although further research on the reasons for this is needed.