Eyeworld

SEPTEMBER 2022 | EYEWORLD | 75 G Contact Kahook: malik.kahook@gmail.com Mandava: Naresh.Mandava@ cuanschutz.edu Weng: Christina.Weng@bcm.edu Relevant disclosures Kahook: Alcon, Aurea Medical, Equinox, Fluent Ophthalmics, Johnson & Johnson Vision, New World Medical, SpyGlass Ophthalmics, SpyGlass Pharma Mandava: None Weng: Allergan, Alcon, Alimera Sciences, DORC, Genentech, Novartis, Regeneron, REGENXBIO pressure is mildly elevated, he will move for- ward. But if it's elevated into the mid-20s or higher, he thinks about what the cause may be, examines the eye and drainage system, makes sure there are no other issues, and looks at optic nerves to see if there's any evidence of asymme- try. If it's above a certain pressure, he may with- hold the injection, start the patient on topical medication, and see them back for the injection. Injections in the setting of MIGS/other glaucoma procedures For those with a history of MIGS/glaucoma surgery, there is no consensus on whether to modify the injection or peri-injection approach, Dr. Weng said. "I am always mindful of where trabeculectomy blebs or tube shunt plates are located and avoid injecting through these areas, but I do not currently do anything differently for these patients aside from reminding them to continue with regular follow-up with their glaucoma specialist and monitoring their pre-in- jection IOP each time they come to see me," she said. Dr. Weng said she also likes to involve a glaucoma specialist any time she is concerned that an injection-associated IOP elevation is becoming persistent, as they will be best able to assess whether a patient requires surgical inter- vention. "Fortunately, of the millions of intravit- real injections given each year, only a very small proportion of patients will require a glaucoma procedure as a direct result of injections." When IOP spikes occur Dr. Kahook said that IOP spikes post-anti-VEGF injections come in two forms. "The first is an acute rise that happens in the majority of pa- tients and is related to the expansion of volume within the eye and necessitates time for the eye to reequilibrate," he said. This can be seen in both healthy and glaucomatous eyes, but it takes longer for eyes with glaucoma to reequil- ibrate given the compromised aqueous outflow channels. "The second form of IOP elevation is chron- ic and can be seen after one or more injections and can last for weeks to months or longer if not treated with medications or surgical intervention," Dr. Kahook said, adding that it is this second form that results in higher rates of morbidity if not diagnosed and addressed. "This is also the reason that I advocate for making IOP checks part of the routine injection clinic workup before each injection takes place." Dr. Weng said spikes are not uncommon immediately following the injection but usually will return to baseline within 30–60 minutes. What is less understood are the late-onset IOP spikes that can occur months or even years after a cumulative number of injections. "With intravitreal steroid injections, you can also see a subacute IOP spike in about one-third of patients that typically occurs 4–6 weeks fol- lowing the injection, which is why I bring these patients back in that timeframe to check their IOP," she said. What to do after an IOP spike A post-injection IOP elevation will typically resolve on its own within an hour, Dr. Weng reiterated, but if it persists with an IOP >35 mm Hg after a reasonable wait time in the office, she'll start an IOP-lowering drop and see that patient back again in a few days. If it per- sists with an IOP >35 mm Hg and the patient has pain or corneal edema due to the elevated IOP, she will consider performing an anterior chamber paracentesis and discharge the patient on IOP-lowering drops. "If the patient has a higher than average risk for glaucoma, I would also consider referring to a glaucoma specialist for baseline evaluation," she said. Dr. Weng added that the risk of vision loss from the many diseases that intravitreal injec- tions treat is significantly greater than the small risk of injection-induced glaucoma. "However, there needs to be more research conducted in this area so that we can continue to optimize the safety profile of intravitreal injections, the most common ophthalmic procedure we do today," she said.

• Cover