In comparison with a hydrophobic acrylic IOL with a sharp posterior optic edge, a hydrophilic acrylic IOL was associated with almost twice the number of Nd:YAG-laser treatments over a 5-year period, according to a study in the British Journal of Ophthalmology.1
Björn Johansson, MD, PhD, of the Department of Ophthalmology, Linköping University Hospital, Sweden, conducted an epidemiologic, longitudinal retrospective cohort study to evaluate the number of capsulotomies performed in a population of unselected cataract patients over a 5-year period after phacoemulsification.
The study included 900 eyes (900 patients; mean age, 76.7 years) who underwent phacoemulsification with IOL implantation from January 2000 through September 2002. Patients received either the AR40 IOL (Abbott Medical Optics Inc. [AMO], Santa Ana, California; n=300), a hydrophobic three-piece lens with a rounded posterior optic edge; the AR40e IOL (AMO; n=300) a hydrophobic three-piece lens with a sharp posterior optic edge; or the BL27 IOL (Bausch + Lomb, Rochester, New York; n=300), a hydrophilic one-piece IOL with a sharp posterior optic edge and two nonangulated loop haptics.
At 5 years postoperative, 216 eyes (24%) had received Nd:YAG-laser treatment. According to Dr. Johansson, statistically significant differences in treatment rates were found between the IOLs, with 91 eyes in the BL27 group, 73 eyes in the AR40 group, and 52 eyes in the AR40e group (P <.001) requiring capsulotomies. Eyes of patients who died during follow-up had fewer capsulotomies (23 of 266 patients) than eyes of patients living (193 of 634 patients) at the end of the follow-up. Overall, hydrophobic acrylic IOL material and square posterior optic edge together were associated with significantly lower numbers of capsulotomies compared with hydrophilic IOLs, the study author said.
“As a consequence of a long follow-up time, other models have usually replaced the IOLs investigated at the time of study publication, which is the case for all three IOLs in this study,” Dr. Johansson wrote. “However, both the IOL materials and the sharp posterior optic edge design are used in presently marketed models. Therefore, these results can provide a basis for discussion about the long-term economic consequences of choosing an IOL whose design makes PCO development more or less likely.”