Trabeculectomy With Mitomycin-C Outcomes Improved By Intraoperative Bevacizumab

Trabeculectomy with mitomycin-C (MMC) better reduces the need for additional glaucoma medication or further surgery to achieve target intraocular pressure (IOP) when paired with a single dose of adjunctive bevacizumab delivered during trabeculectomy, according to research published in the British Journal of Ophthalmology. The study evaluated patients 1 year after undergoing the glaucoma surgery.

When trabeculectomy with MMC fails, it is often within the first 2 months after surgery, according to previous studies. The researchers aimed to evaluate the effect of adding intraoperative bevacizumab to the treatment.

From 2016 to 2018, researchers recruited adult patients for the double-blinded, randomized, placebo-controlled trial who were receiving care from glaucoma outpatient clinics in Australia and needed trabeculectomy. Patients received either 1.25 mg in 0.05 mL intravitreal bevacizumab (n=64) or placebo (n=64) at the end of the surgery.

Researchers performed bleb photographs and measured patients’ intraocular pressure (IOP) and best central visual acuity (BCVA) after trabeculectomy with mitomycin-C. Using these findings, they categorized patients as having “complete success” (IOP no greater than the target IOP, without additional medication) or “qualified success” (IOP no greater than the target IOP but topical medication was necessary).

At 1 year postoperative, patients who received trabeculectomy with MMC and did not achieve “complete success” were less likely to have received intraoperative bevacizumab compared with those who did receive the injection (6% vs 17%, P =.015). 

Among the 11% of individuals with primary open-angle glaucoma (POAG)/normal-tension glaucoma (NTG), significantly more patients in the control group failed to meet the criteria for either ‘complete success’ or ‘qualified success’ (8%) compared with the bevacizumab group (0%, P =.031).

Bleb needlings and reduction of IOP statistically significantly favored use of bevacizumab at 1 month. Need for topical therapy was linked with the control group at 6 months and 1 year (P =.047). Bleb height was greater in the bevacizumab group at 1  month and at 1 year. 

Patients who underwent trabeculectomy with MMC and received intraoperative bevacizumab had less vessel inflammation in the central and peripheral bleb and non-bleb conjunctiva at 1 month.

“Bevacizumab interrupts the fibroproliferative phase of wound healing. The effect of this would be less thickening and, thus, less resistance to aqueous diffusion at the level of the tenon’s capsule and the conjunctiva. Previous work has raised concerns that bevacizumab might lead to a higher prevalence of avascular blebs or tenon’s cysts,” the researchers explain. “Our paper showed that although the prevalence of avascular blebs increased over the 12-month follow-up time, it did so in both groups with no significant differences.”

Study limitations include brevity of follow-up time and possible confounding bias associated with combined phacoemulsification trabeculectomy.