Careful attention to detail can optimize refractive outcomes in trabeculectomy and large aqueous shunts, reported Cynthia Mattox, MD.
Dr. Mattox, director of the Glaucoma and Cataract Service, New England Eye Center, Tufts University, Boston, described state-of-the art techniques for the procedures.
“Frankly, not only do our patients have higher expectations of what their postoperative outcomes are going to be, we have our own high expectations,” she said.
The first step is to evaluate carefully the refractive status of both eyes, she said. Does the patient have cataracts or astigmatism? High myopia or hyperopia?
Next, consider the current level of IOP, and the desired level of postoperative IOP. This is particularly important in a combination of phacoemulsification with trabeculectomy, because going from a very high to a very low IOP will shorten the axial length, said Dr. Mattox.
“So for patients where you’re planning to go with a very low pressure postoperative in a combined procedure, you may want to pick the lens implant to be a little bit on the myopic side and you’ll probably end up just right,” she suggested.
Case emphasizes point
She gave the example of a 70-year-old female with advanced primary open-angle glaucoma and IOP at 18 mm Hg, who was continuing to lose vision. The patient had a 20/40 cataract and a pre-existing astigmatism of 4 D against the rule.