The force necessary to change the lens diameter and lens power increases with age in human and monkey lenses. The results agree with the Helmholtz theory of accommodation and with presbyopia theories that predict that the force required to disaccommodate the lens increases with age.

Purpose: To evaluate the clinical consequences of complications from neodymium:YAG (Nd:YAG) laser capsulotomy for posterior capsule opacification (PCO) over the lives of cataract patients.Setting: CHU de Caen, Caen, France. Methods: A model was constructed to estimate the lifetime clinical consequences of postoperative PCO treated by Nd:YAG laser capsulotomy. The probability of death was modeled from French mortality tables as a polynomial function of sex and age. The probability of becoming blind was modeled as a function of age from data in the literature. The incidence of Nd:YAG complications came from the literature. The rate of Nd:YAG capsulotomy over time was modeled as a survival curve using data from a cohort of 3335 patients. Results:Over 9 years in a 70-year-old population, switching from an IOL with a 20% Nd:YAG capsulotomy rate at 3 years to an IOL with a 5% rate would avoid 1 chronic intraocular pressure increase requiring medical follow-up in every 54 surgeries, 1 case of glaucoma in every 237 surgeries, 1 case of cystoid macular edema in every 265 surgeries, and 1 retinal detachment in every 265 surgeries. A 3-year clinical study would only capture one-third to one-half of long-term adverse events of Nd:YAG capsulotomy. Conclusion:Reducing PCO and the associated use Nd:YAG laser capsulotomy may contribute to preserving visual acuity in patients over their lifetimes. C ataract is a normal consequence of aging and is proliferate and migrate into the space between the postereported to develop in 18% of people between rior surface of the intraocular lens (IOL) and the postethe ages of 65 years and 74 years and in 46% between 75 years and 85 years. 1 Surgery remains the only effective rior capsule. treatment for cataract.Several studies 4-15 have compared the incidence of Surgical treatment of cataract improves the patient's postoperative PCO between different IOL types. These vision and quality of life. 2,3 The most frequent poststudies had various experimental designs (eg, prospecoperative complication of cataract surgery is posterior tive randomized clinical trial including cross-over decapsule opacification (PCO). 2 Posterior capsule opacifisign, retrospective cohort analysis, patient chart analysis) and assessed a variety of outcomes (eg, PCO rate, use of the neodymium:YAG [Nd:YAG] laser). The results Accepted for publication February 26, 2004. were fairly consistent and show a decreased PCO rate From CHU de Caen (Billotte), Caen, and Alcon France (Berdeaux), in recent years. The difference in the PCO rate between Rueil-Malmaison, France.IOLs may also be the result of methodology such as Supported by an unrestricted grant from Alcon Laboratories Inc.

Distilled water and 10 mM EDTA treatments were the most efficient in retarding the appearance of PCO.