Refractive outcomes of combined cataract and glaucoma surgery

Purpose: This study was designed to evaluate the refractive outcomes of combined cataract extraction and glaucoma surgery. Design: Retrospective case series. Methods: A retrospective chart review of patients undergoing simultaneous cataract extraction with trabeculectomy or glaucoma drainage device surgery was performed. The main outcome measure evaluated was whether or not spherical equivalent of -1.00 to +0.50 D was achieved at 3 to 6 months postoperatively. Secondary outcomes included: reduction in intraocular pressure, amount of cylinder induced by combined surgery, and individual patient characteristics that may have affected refractive outcome. Outcomes were compared with an age-matched and sex-matched control group of patients who had uncomplicated cataract surgery during the same time period. Results: Forty-three eyes of 36 patients underwent combined cataract extraction and glaucoma surgery. A refractive outcome of spherical equivalent between -1.00 and +0.50 D was achieved in 32 of 43 eyes (74%) at 3 to 6 months after surgery. Logistic regression analysis found a 1.14 increased risk of the refraction being outside this defined refractive range in older compared with younger patients (by year, 95% CI, 1.04-1.27). Type of lens implant used, type of glaucoma surgery, and preoperative best-corrected visual acuity did not significantly affect refractive outcome. In a subset of 22 eyes with available preoperative keratometry measures, a mean 1.31 D (SD=0.86; range, 0.26 to 3.76) of corneal astigmatism was induced by combined surgery. In comparison, a matched control group who had cataract surgery alone achieved target refractive outcome in 34 of 40 eyes (85%, P=0.001) and had a trend for less induced cylinder (0.99, SD=0.72, P=0.11). Conclusions: Favorable refractive outcomes were achieved in the majority of patients despite the potential alteration of preoperative measurements and introduction of error into lens selection when using a combined approach. There does not seem to be a difference in the refractive outcome with regard to the type of glaucoma surgery performed. Control patients who had cataract surgery alone had a higher percentage of achieving target refractive goal and less induced cylinder.