Sir,

Neovascular glaucoma (NVG) is refractory to conventional surgeries including trabeculectomy with mitomycin C (TMMC).1 Previous vitrectomy, in particular, can adversely affect the outcomes of subsequent TMMC.1, 2 Several studies have reported that bevacizumab (Avastin, Genentech, South San Francisco, CA, USA) can control neovascular activity in eyes with NVG.3, 4, 5 We conducted a pilot study to evaluate the efficacy of intravitreal bevacizumab (IVB) as a preoperative adjunct for primary TMMC to treat NVG in previously vitrectomised eyes.

A total of 15 eyes of 15 consecutive patients (10 men, 5 women) who had undergone a previous vitrectomy received IVB (1 mg) followed by planned TMMC. All patients were followed for more than 1 year postoperatively. The mean patient age was 58.3±11.3 years (31–71 years). NVG was secondary to proliferative diabetic retinopathy in 11 eyes (73%), ocular ischaemic syndrome in 3 eyes (20%), and central retinal vein occlusion in 1 eye (7%). A total of 11 eyes had one, 2 eyes had two, and 2 eyes had three previous vitrectomies. The interval between IVB and TMMC was 10.0±6.4 days (1–22 days). All patient data are shown in Table 1.

Table 1 Demographics and outcomes of 15 cases
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The mean intraocular pressure (IOP) reduced significantly from 41.3±11.9 mm Hg (25–62 mm Hg) at baseline to 13.6±7.0 mm Hg (4–32 mm Hg, P<0.001, one-way ANOVA followed by Tukey’s test) at 1 month, 13.9±4.5 mm Hg (6–18 mm Hg, P<0.001) at 3 months, 15.3±5.1 mm Hg (8–23 mm Hg, P<0.001) at 6 months, and 15.4±5.2 mm Hg (4–25 mm Hg, P<0.001) at 1 year postoperatively. The success rates defined as IOP below 21 mm Hg without loss of light perception and additional anti-glaucoma surgeries were 87% after 1 and 3 months of follow-up, 80% after 6 months, and 73% after 1 year (Figure 1). Failure (four eyes, 27%) was attributed to the additional glaucoma surgery in three eyes and an IOP over 21 mm Hg in one eye.

Figure 1
figure 1

Kaplan–Meier survival curve analysis of surgical outcomes in 15 eyes treated with adjunctive intravitreal bevacizumab followed by trabeculectomy with mitomycin C. Cumulative survival (success) is defined as an intraocular pressure of 21 mm Hg or lower without additional anti-glaucoma surgery and loss of light perception vision. The overall success was 73% at 1 year.

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Previous studies have reported that the 1-year success rate of TMMC without bevacizumab for NVG in previously vitrectomised eyes was about 50%, which is lower than that of the current study.1, 2 Preoperative adjunctive use of bevacizumab before trabeculectomy might improve the surgical success rate of NVG in previously vitrectomised eyes.