I have also evaluated ABiC in patients with severe glaucoma. These patients do not do quite as well as those with mild-to-moderate glaucoma, most likely because the distal drainage system in severe patients is usually in an advanced state of disease. Nonetheless, I still tend to use ABiC as a first-line treatment for patients with severe glaucoma to try and avoid invasive filtering surgery. I’m comfortable doing this knowing that I still have around an 80% chance of filtering surgery—for 2 years at least.
Though ABiC is suitable for the majority of patients with glaucoma, it is not a panacea. Some patients will gain less from the procedure. For the most part, it requires a relatively well-functioning trabecular meshwork. Consequently, ABiC is of little benefit for patients with a diseased trabecular meshwork, because aqueous still has to traverse this structure to enter Schlemm’s canal.
I am often asked about the treatments I choose for a given patient and how I choose them. The simplest answer is that I try to tailor treatment according to my patients’ needs. However, for cataract patients with glaucoma, I always add a MIGS to reduce IOP or medication use.
Gonioscopy is an important tool in my preoperative evaluation. If I see a patient with a relatively diseased trabecular meshwork and a variegated pattern of pigmentation, I like to perform some form of trabecular microbypass or trabecular ablation. In all other patients, if I see a relatively normal-looking drainage angle, I use ABiC.
ABiC is not the only MIGS I use in my practice. I implant quite a few stents (iStents, Glaukos) and perform other ablative procedures as well. I tend to use the stent instead of ABiC if the trabecular meshwork appears diseased. In patients with pseudoexfoliative, pigmentary, or uveitic glaucoma, I prefer trabecular ablative procedures, such as gonioscopy-assisted transluminal trabeculotomy (GATT) or focal goniotomy with a dual blade (Kahook Dual Blade, New World Medical).