Eyeworld

SEPTEMBER 2023 | EYEWORLD | 63 G Relevant disclosures Kassotis: None Qiu: None Shukla: None Sun: None Wang: None Contact Kassotis: ak4129@cumc.columbia.edu Qiu: mary.qiu@gmail.com Shukla: ag2965@cumc.columbia.edu Sun: Catherine.Sun@ucsf.edu Wang: jessie.wang@uchicagomedicine.org open up the angle across the entire 360 degrees. However, many patients with NVG may be on chronic blood thinners, which increases the risk of bleeding-associated complications after GATT, and Dr. Qiu does not offer GATT in patients who cannot hold anticoagulation. Dr. Qiu and Dr. Wang added that MIGS cannot be performed in eyes with complete syn- echial closure of the angle. "In this challenging cohort of patients, medications likewise often do not adequately lower the IOP," Dr. Wang said. "In those patients with synechial closure and IOP too high for the health of the optic nerve, prompt laser procedures such as CPC and incisional surgery such as tube shunt implan- tation are standard of care. Finally, during the treatment of neovascular glaucoma, follow-up with the retina service is crucial to control the underlying ischemic retinal disease." She noted that failure to do so often leads to recurrence of neovascularization and new formation of peripheral anterior synechiae, which would lead to failure of the MIGS that has been performed. Anti-VEGF and PRP for patients with neovascular glaucoma Dr. Sun said that anti-VEGF injections are given intravitreally and can lead to rapid regression of neovascularization. These include regression of NVI and NVA. "However, if synechiae an- gle closure has already developed, anti-VEGF injections may be less effective at normalizing IOP. They will cause regression of NVI or NVA but the synechiae angle closure will remain," she said. Dr. Kassotis said that in normal aqueous humor, VEGF is absent, while high levels of VEGF accumulate in the aqueous of those with ischemic anterior segment conditions, such as NVG. VEGF induces angiogenesis in response to the relative hypoxia, leading to iris and angle neovascularization and increased IOP. Given VEGF's integral role in NVG pathogenesis, VEGF inhibition has emerged as an important modali- ty in NVG treatment. 4,5 Anti-VEGF leads to rapid reduction in anteri- or segment neovascularization, Dr. Kassotis said, adding that anti-VEGF agents can be adminis- tered as intravitreal or intracameral injections. 4 While angiography demonstrates that anti-VEGF significantly decreases leakage of the aberrant vessels, vessel complexes do not regress com- pletely, unlike in panretinal photocoagulation. Management of NVG depends on visual potential and patient comfort, Dr. Kassotis said. "Aggressive medical management with topical and oral IOP-lowering agents is helpful acutely, often as a segue to more definitive manage- ment," she said. While anti-VEGF is helpful in the short term for open angle NVG, PRP has been used in ischemic disease for decades. It is efficacious both in the early and more advanced stages of NVG (including closed angle NVG), thus is considered a mainstay of treatment despite the advances of anti-VEGF. PRP reduces aqueous VEGF levels more than anti-VEGF and structurally reduces the number of anterior segment neovessels. 6 Optimizing outcomes Depending on the underlying etiology for reti- nal ischemia, additional systemic treatment may be needed, Dr. Sun said, adding that PDR is the most common cause of NVG. "For these patients with diabetes mellitus, their blood glucose and blood pressure should be controlled," she said. "I recommend that these patients see an endo- crinologist if they do not have one." Dr. Sun stressed that prevention is the most important way to stop vision loss from NVG. "This includes education to patients who have conditions that make them at high risk for NVG, such as diabetic retinopathy and retinal vein occlusion," she said. "For non-glaucoma provid- ers who care for these patients, incorporating gonioscopy into routine practice in patients who are high risk is important for the earliest diagnosis. If early neovessels can be detected before the angle has synechially closed, these patients may have a chance of preserving their natural aqueous outflow pathway and not need glaucoma surgery." There are a number of other challenges to optimal care for NVG patients once they develop NVG that she, Dr. Qiu, and Dr. Shukla discussed in an editorial in Ophthalmology Glau- coma. 7 "We felt that 'multidisciplinary discus- sions in ophthalmology are needed around the following topics: (1) standardizing the defini- tion and staging of NVG; (2) detecting anterior segment neovascularization earlier; (3) increas- ing evidence-based research to improve out- comes; (4) determining the optimal multidisci- plinary treatment approach; and (5) increasing patient adherence to treatment.'"

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