Refractive error with optimum intraocular lens power calculation after glaucoma filtering surgery

PURPOSE: To assess the possibility of deriving an optimum intraocular lens (IOL) power after previous successful trabeculectomy. SETTING: Chang Gung Memorial Hospital, Linko, Taiwan. METHODS: The retrospective study included 1 eye of 22 patients who had cataract surgery after successful trabeculectomy performed by 1 surgeon. Twenty-two eyes that had cataract surgery only performed by the same surgeon were paired as a control group. The IOL power was calculated by the Sanders-Retzlaff-Kraff regression analysis formula based on the data derived after trabeculectomy. The postoperative refractive error at least 1 month after cataract surgery was recorded, and the difference was analyzed by a paired t test and 2-sample t test. RESULTS: Cataract surgery combined with trabeculectomy resulted in a mean spherical equivalent of -0.33 diopter +/- 1.58 (SD). This was not significantly different from the predicted refractive error or the result in the control group (P>.05). CONCLUSION: Although the fluctuation in pseudophakic axial length measurement after glaucoma filtering surgery was logical, a predictable pseudophakic refractive outcome was derived clinically once the intraocular pressure stabilized after trabeculectomy.