Multiple studies have found that cataract surgery lowers IOP in most patients, including people with glaucoma and ocular hypertension.
These IOP-lowering effects have been observed to last for up to ten years, and may even reduce the need for antiglaucoma medications postoperatively: specifically, one study found that 47 percent of patients with glaucoma no longer needed antiglaucoma medications at 12 months, and 38 percent of patients no longer needed medications at 24 months.
When faced with this research, choosing to perform cataract surgery on a patient with glaucoma may seem like the obvious choice. After all, cataract surgery won’t just improve the patient’s vision – it’ll also curb their glaucoma.
Unfortunately, not all patients receive this IOP-lowering boost. Some may even experience postoperative pressure spikes.
So what should you do?
Don’t treat them like a normal cataract patient.
Patients with comorbid cataracts and glaucoma shouldn’t be treated like a typical cataract patient. During the consultation period, make sure that you thoroughly evaluate their medical history. Which medications are they taking? What is their IOP? What is the current state of their optic nerve? All of these factors can influence the surgery itself, so you’ll need to cover all of the bases.
Not all patients with glaucoma experience a significant drop in IOP after cataract surgery. In a 2014 study, researchers from the University of Washington in Seattle looked at 157 open-angle glaucoma patient eyes undergoing cataract surgery. Over a third of these eyes either 1) required additional medications or laser treatments to control IOP during the first year postoperatively or 2) were found to have a higher IOP during the first postoperative year despite leaving their medication regimen unchanged.
Even though cataract surgery might decrease your patient’s IOP, plan for the worst and make sure you’re ready to act.
Think about a combination procedure.
Performing cataract surgery and glaucoma surgery concurrently may be the right decision for some patients, particularly those with severe glaucoma. (For a great piece about combination surgery, we recommend this article.) In other cases, it might be better to perform the surgeries consecutively, or perform cataract surgery and then carefully monitor the patient’s IOP to determine the next steps.
Consider postsurgical medication.
Several studies have found that administering antiglaucoma medications postoperatively may reduce IOP spikes. In one study, researchers found that giving patients one drop of timolol maleate immediately post-surgery eliminated IOP elevations greater than 30 mm in all glaucoma patients during the first 24 hours. Another study found that topical dorzolamide is also effective at reducing IOP spikes in the first 24 hours after surgery.
Watch out for topical corticosteroids.
Topical corticosteroids can reduce inflammation and complications after cataract surgery. Unfortunately, a portion of the population are steroid responders, which means that using these drugs can increase IOP. Although steroid responders make up one third of the general population, they make up 90 percent of individuals with primary open-angle glaucoma.