PREDICTION OF VISUAL FUNCTION AFTER CATARACT-SURGERY - A PROSPECTIVELY VALIDATED MODEL

Objective: To develop a model to predict visual functional improvement after cataract extraction with intraocular lens implantation based on preoperative data. Design: A prospective study with serial evaluation s of visual function preoperatively and at 3 and 12 months after surge ry. Setting: The General Eye Service of the Massachusetts Eye and Ear Infirmary, Boston, Mass, and 33 ophthalmology practices in Boston. Pat ients: Patients (N=426; ages, greater than or equal to 65 years) who w ere undergoing cataract surgery. Methods: Twelve-month improvement in visual function was measured by using the Activities of Daily Vision S cale (ADVS). Ordinal logistic regression was used to identify correlat es of improved ADVS scores in 281 patients (derivative set). Potential factors included the preoperative visual acuity, preoperative ADVS sc ore, four chronic ocular diseases, eight medical conditions, and demog raphic characteristics. Five predictors were identified and used to co nstruct a prediction rule. The accuracy of the prediction rule was eva luated in an independent group of 145 patients (validation set). Resul ts: Postoperatively, 40% of the 281 patients in the derivative set had substantial improvement in their ADVS scores, and 53 (19%) had some i mprovement. Predictors of improvement included younger age (P<.001), a poorer preoperative ADVS score (P<.001), posterior subcapsular catara ct (P=.09), and absence of age-related macular degeneration (P=.07) an d/or diabetes (P=.006). When applied to the independent sample of 145 patients, these five characteristics classified the patients into thre e groups in which the probabilities of substantial improvement were 85 %, 34%, and 3%, thus verifying the discriminatory power of the predict ion rule. Conclusions: Preoperative data can identify patients who are likely to have improvements in visual function after cataract surgery . Such findings may be useful in the selection of patients for this hi gh-volume procedure.