Eyeworld

80 | EYEWORLD | SEPTEMBER 2021 G UCOMA References (cont.) 6. Wells AP, et al. Cystic bleb formation and related complications in limbus- ver- sus fornix-based conjunctival flaps in pediatric and young adult trabeculectomy with mitomycin C. Ophthalmology. 2003;110:2192–2197. 7. Gedde SJ, et al. Treatment outcomes in the Primary Tube Versus Trabeculectomy Study after 3 years of follow-up. Oph- thalmology. 2020;127:333–345. Relevant disclosures Herndon: Alcon Rhee: Glaukos, Ivantis Contact Herndon: leon.herndon@duke.edu Rhee: dougrhee@aol.com he noted the data haven't shown the same pressure-lowering effects as trabeculectomy. Dr. Rhee agreed with Dr. Herndon that there is still nothing that can lower pressure as well as trabeculectomy. "We don't have anything that's as modifiable in the postop period," he added. The other options are to wait and see or add glaucoma medications. The only other procedure that offers the ability to modify it postoperatively is deep sclerectomy, Dr. Rhee said, where you can laser open Descemet's window. But with trabeculecto- my, there are things physicians can do to modify the wound healing response. "Trabeculectomy has a lot of features that we wish we could change, but to date nothing has come along to unseat it as the gold stan- dard," Dr. Rhee said. The closest thing is tubes shunts, but even these have not been shown to be superior to trabeculectomy. 7 "Just because it's the gold standard doesn't mean that it's always the first-line procedure," Dr. Rhee said. "It depends on the patient's indi- vidual need." Trabeculectomy may be the most effective procedure, but it's certainly not the safest, he continued. In the appropriate situation, you still might do trabeculectomy first. It might be a good first-line approach for those who need very low target pressures. He also mentioned the EX-PRESS Glaucoma Filtration Device, which he said is recognized as its own procedure with its own billing code, though there is some debate if it is truly unique in its mechanism or if it is an enhancement for trabeculectomy. "You do a trab, but instead of making a hole in the iridectomy, you put in an EX-PRESS shunt, and everything else is like a trab," he said. Dr. Rhee also mentioned PRESERFLO and the XEN Gel Stent (Allergan) as potential options, but he again reiterated the 50-year his- tory of positive pressure-lowering results with trabeculectomy. fornix-based, the latter of which is more popular now. "What we do now isn't exactly what was ini- tially published/studied, but it closely resembles it," Dr. Rhee said. He added that in the 1970s and 1980s, there was some experimentation with different shapes and sizes of flaps, but it was determined that this didn't make much of a difference. What did make a difference, he said, was in the early 1980s, when Heuer et al. published the 5-FU trial of the first antimetabolite, which was designed to inhibit scarring and improve the survivability of the trabeculectomy. 3 The next big advent, he said, was the use of mitomycin-C, credited to Chen et al. 4 and Kitazawa et al. 5 Dosing and timing of mito- mycin-C has continued to be studied over the years. Finally, Dr. Rhee mentioned the evolution of fornix-based flaps. Prior to this, physicians had been doing limbal-based flaps. Wells et al. pub- lished a study showing that fornix-based flaps do well, 6 Dr. Rhee said. In modern trabeculecto- my, the vast majority of glaucoma specialists use these, he said, but some still use limbal-based, which is a good option. Gold standard despite other options Dr. Herndon said he thinks trabeculectomy will be around for the foreseeable future until "we have a procedure that will get those trab-level pressures." "I've been doing this so long, and I wince when I see some patients on whom I [did tra- beculectomy] 20 years ago who just had mild disease and they have huge blebs that are caus- ing irritation, leaking, and potentially infection," he said. "I would not recommend trab for mild to moderate disease at this point until you try something less invasive first." Still, Dr. Herndon doesn't see the proce- dure going away. He said when the EX-PRESS Glaucoma Filtration Device (Alcon) came on the market, this helped take trabeculectomy to the next level. Dr. Herndon is excited about the PRESERFLO MicroShunt (Santen), though continued from page 79

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