27 patients treated with combination compared to

15 consecutive subsequent controls treated with AVS alone, edaravone improved visual outcomes.174 AVS has also been compared to vitrectomy without AVS. The effects were similar to those seen by the same authors with AVS, calling into question whether sheathotomy adds value to vitrectomy alone.77,310

In the hazardous task of comparing relative effectiveness of treatments in the absence of prospective randomized clinical trials, Fish concluded that AVS was more effective than IVB but at greater cost, complication rate, and inconvenience of a surgical as opposed to ofÞce-based procedure.79

With the introduction of anti-VEGF therapy and its more reproducible effect of improving VA, this treatment has been abandoned.

13.4.1.9 Vitrectomy

Vitrectomy with stripping of the posterior hyaloid has been used in uncontrolled case series as treatment for the ME associated with BRVO with consistent improvement in ME and less consis-

tent improvement in VA.21,171,176,177,200,230,244,271,310,312

Macular edema increases after such surgery in approximately 20% of eyes, but the effect is transient and spontaneously resolves with ultimate thinning of the macula in most cases without the use of pharmacotherapy.256 Macular microcirculation improved after vitrectomy for ME associated with BRVO in one series.200

The effect of vitrectomy on ME associated with BRVO develops slowly and progressively with mean time to full macular thinning postoperatively occurring from 9 to 12 months.77 Adjunctive use of triamcinolone as an aid to visualize the posterior hyaloid and the internal limiting membrane may accelerate this thinning with a stable reduction in ME by 4 months after surgery.171

Vitrectomy with PRP to ischemic retina has also been used in a case series with reported signiÞcant improvement in ME and VA.312 The efÞcacy was greatest for eyes with higher preoperative vitreous concentrations of VEGF but not IL-6.312 In the absence of a control group, it is not possible to state with certainty the

efÞcacy of such an approach relative to the natural history.

Vitrectomy with ILMP for BRVO with chronic ME unresponsive to GL treatment has been described in uncontrolled case series.13,171,205 A disproportionate improvement in ME relative to VA was observed in some series, although VA, on average, did improve, perhaps due to the chronicity of the edema before the vitrectomy.13,171,205

A similar surgical approach for BRVO with ME and foveal hemorrhage has been described in an uncontrolled case series.154 On average, VA improved over the course of 1 year of follow-up.154 In the absence of a randomized controlled clinical trial, this approach has not been widely adopted.

Other combination treatment approaches involving vitrectomy have been reported, including vitrectomy plus subretinal TPA injection and vitrectomy with intraoperative IVTI followed by postoperative PSTI for recurrent or persistent macular edema.160,287 The addition of IVTI to vitrectomy accelerates macular thinning compared to vitrectomy alone, but recurrent edema when the drug wears off remains a problem.287 These methods have not been taken up by others.

Better preoperative VA was correlated with better Þnal VA.271 Macular edema improved more after vitrectomy in eyes with higher preoperative levels of VEGF.312 In three series, duration of BRVO was an important factor for visual outcome. Patients operated earlier (with deÞnitions of ÒearlierÓ varying from less than one to less than 11 months since onset of symptoms) showed improved VA outcomes.176,244

Vitrectomy for ME associated with BRVO signiÞcantly improves vision-related quality of life.204 Three months after surgery, the composite score on the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25) improved from a preoperative mean of 54 ± 15.5 to 64.9 ± 15.0 (P < 0.05).204

No randomized clinical trial has been done to compare the efÞcacy of vitrectomy for BRVO with ME to either GL or serial intravitreal injections of anti-VEGF drugs, which have been proven to be effective. Therefore, the place of vitrectomy in management of ME associated with BRVO remains speculative, but it probably should be reserved for cases refractory to proven therapies.