Eyeworld

100 | EYEWORLD | SPRING 2024 G UCOMA by Liz Hillman Editorial Co-Director About the physicians Marlene Moster, MD Professor of Ophthalmology Sidney Kimmel Medical College Thomas Jefferson University Philadelphia, Pennsylvania Pradeep Ramulu, MD, PhD Chief, Division of Glaucoma Wilmer Eye Institute Johns Hopkins University Baltimore, Maryland I t's heartbreaking and hard to understand: A patient has glaucoma and despite a normal or low IOP, their disease is progressing. Mar- lene Moster, MD, and Pradeep Ramulu, MD, PhD, provided their thoughts on diagnosis of normal tension glaucoma (NTG), establishing true progression, and how to manage worsening disease in this patient population. According to Dr. Ramulu, half or more glaucomas develop at low pressures. "Once you start getting to really low pressures, it can be a bit of a surprise that someone has glau- coma … because most of the people who have glaucoma developing at low pressures are still in the upper half of what's normal, usually 15 mm Hg and above," Dr. Ramulu said. "When you start getting below that, it becomes rela- tively uncommon. The more troubling, and less common, scenario is someone who appears to be getting worse when their eye pressure is well controlled." Is it really NTG? When it comes to establishing an initial diagno- sis of NTG, Dr. Moster and Dr. Ramulu said it's important to ensure that it's truly NTG. Dr. Moster said when a patient is sent in for a diagnosis and treatment of NTG, it's important to look for red flags so that other treatable optic neuropathies are not missed. "For example, we look very carefully for an atypical visual field with temporal loss. If the cupping is similar in both eyes but there is a large afferent pupillary defect, I'm concerned there is a neurologic process going on. We look for color loss, dy- schromatopsia, because there is not much color loss in glaucoma, but there is profound loss in neurologic disease," she said. "I look for pallor of the rim of the optic nerve more than cupping; asymmetric pallor is indicative of neurologic disease." She said that other neurologic symptoms to watch out for are headache, motility defects, and diplopia. "Also, I look for decreased vision out of proportion to what I would expect looking at the optic nerve because with neurologic disease, vision is usually poor, but with glaucoma, even at the end, there is good central vision. I also look for ganglion cell layer loss that is atypical on OCT, looking for an atypical paracentral defect that will show up on the ganglion cell complex or nasal defect that is atypical. Also, very young patients are unlikely to have normal tension glaucoma and may instead have neuro- logic disease," she said. If a patient has a red flag, Dr. Moster said she refers the patient to neuro-ophthalmology for further testing. Establishing progression When visual fields and/or OCT suggest that a patient with NTG is progressing despite a low IOP, Dr. Ramulu said he likes to first establish that it's true progression. He asks the patients about their symptoms. Are they experiencing a Current perspectives on NTG and progression at low IOPs bi-monthly, and for many patients, the duration is indefinite," Dr. Schehlein said. "As there is some data that increased number of injections can increase the risk of glaucoma surgery and the long-term effect of this new medication on intraocular pressure is unknown, clinicians should consistently monitor their patients' intraocular pressure and proceed with caution in patients with advanced glaucoma. It is worth considering if glaucoma patients starting on these new medications should have glaucoma testing more frequently or if patients with a strong family history of glaucoma, glaucoma suspect, or ocular hypertension should undergo periodic baseline testing while receiving these newer types of injections." Based on early data and experience, Dr. Schehlein's practice is to monitor intraocular pressure closely, especially in moderate to advanced glaucoma patients, with a low threshold to repeat testing soon- er and add treatment, laser, or surgery if the pressure is rising. She added that a side effect of these new IVIs for GA and dry AMD is anterior chamber inflammation, which glaucoma special- ists should be on the lookout for during regular exams. continued from page 98

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