Ocular Comorbidity Predicts Poor Cataract Surgery Outcomes

Lara C. Pullen, PhD

May 01, 2013

Cataract surgery yields excellent visual outcomes for the majority (61.3%) of patients, according to results from a large database study. The greatest influence on visual outcome was found to be short-term postoperative complications, ocular comorbidity, surgical complications, and complex surgery. Age and sex also influenced visual outcomes.

Mats Lundstrom, MD, PhD, from Lund University in Sweden, and colleagues published the results of the study in the May issue of the Journal of Cataract & Refractive Surgery. The data (some self-reported) were drawn from the European Registry of Quality Outcomes for Cataract and Refractive Surgery. The multinational database included information on 368,256 cataract extractions.

The authors found that 94.3% of patients achieved a postoperative corrected distance visual acuity (CDVA) of 0.5 (20/40) or better, and 61.3% had CDVA of 1.0 (20/20) or better. Even patients who experienced less-than-ideal results usually experienced a visual improvement after surgery. However, the researchers did find 5.7% of patients whose vision was unchanged after surgery and 1.7% of patients who experienced worse CDVA after surgery.

The investigators also found that patients with an ocular comorbidity were most likely to experience a CDVA that was less than 0.5 (odds ratio, 3.8). The conditions that were most likely to require a complex surgery were also those that were most likely to compromise surgical outcomes.

"Some clinics use a risk scoring before surgery. In such a scoring system, a brown cataract, pseudoexfoliation, miosis, high age, etc, give [a] higher score...which means need for an experienced surgeon," explained Dr. Lundstrom in an email interview with Medscape Medical News. This approach might help in matching complex surgeries with the appropriate surgeon.

Although surgical complications did demonstrate a weak contribution to surgical outcomes, postoperative complications were more likely to predict a worse postoperative CDVA than that seen before surgery. The study also revealed another, surprising, predictor of outcome: preoperative CDVA.

Dr. Lundstrom described the take-home message for physicians: "In general terms, the outcome is very good. However, if the preoperative visual acuity is very good, there is a risk for poorer vision after surgery. This is obvious if we study patients with a preoperative visual acuity of 1.0 (20/20). [In particular,] patients with good preoperative visual acuity and an ocular comorbidity in the surgery eye have a high risk for deterioration after surgery."

Dr. Lundstrom noted that he was surprised to discover that patients with good preoperative vision and previous corneal refractive surgery were likely to have a poor outcome after a cataract extraction.

Rishi P. Singh, MD, from the Cole Eye Institute of the Cleveland Clinic in Ohio, was also surprised to read about the outcomes for patients with 20/20 vision but thought the rest of the results were more expected. "The study validates that cataract surgery outcomes are quite good for the majority of patients. The risk factors for poorer outcomes are consistent with previous studies and thoughts," he told Medscape Medical News in an email interview.

Dr. Singh, who was not involved in the study, also described some of the limitations of the study, explaining that it relied on a registry that did not have mandatory participation. Therefore, it is possible that bad surgeons would not participate. Dr. Singh also felt that the study provides a local view of the European Union and that it would be difficult to extrapolate the results to the rest of the world.

The authors and Dr. Singh have disclosed no relevant financial relationships.

J Cataract Refract Surg. 2013;39:673-679. Abstract