Better management of hypotonous glaucoma patients having cataract surgery can help ensure great visual outcomes.
Reviewed by Anup Khatana, MD
Careful planning, pre-, intra-, and postoperative modifications can lead to better visual outcomes in hypotonous glaucoma patients when cataract surgery is performed, said Anup Khatana, MD, director, Glaucoma Service, Cincinnati Eye Institute, and volunteer clinical assistant professor, University of Cincinnati College of Medicine, Cincinnati.
Factors that can affect the cataract surgery outcome include a 0.1 to 1.0 mm reduction in axial length after trabeculectomy, an IOP rise after phacoemulsification in eyes with functional blebs, and possible changes in keratometry.
“There is not a lot of data on the effects of cataract surgery on eyes with tubes, but there does not appear to be a significant effect on the IOP,” Dr. Khatana said.
When diagnosing hypotony, the earliest signs are Bowman’s folds or epithelial microfurrows. These can be seen with a cobalt blue light after instilling a drop of 2% fluorescein. Surgeons also should consider how long the hypotony has been present and whether there are any choroidal folds.
“If axial length reduction, choroidal folds or hypotony maculopathy are present for greater than six to nine months, they will likely be permanent,” Dr. Khatana said.
Surgeons have several choices to manage cataract surgery and hypotony, one of which is performing phaco alone. This could be an option if the bleb has some vascularity and looks like it could scar enough to raise the IOP. It is also an option if the hypotony is mild.
A second option, if clinically significant signs of hypotony are present, is to perform a staged procedure to raise the IOP first and perform cataract surgery later. This could involve transconjunctival scleral flap or compression sutures or an open trab revision.
If choosing this option in a patient with hypotony and cylinder of 3 to 4 D or greater, consider adding a scleral relaxing incision posterior to the scleral flap. A third option is a combined phaco and glaucoma revision procedure.
Anup Khatana, MD
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This article was adapted from Dr. Khatana’s presentation at the American Glaucoma Society annual meeting. Dr. Khatana has no related disclosures.