Change in CNV size portends recurrent exudation, subretinal hemorrhage in AMD

Indocyanine green angiography with OCT may help determine when it is time to extend anti-VEGF therapy.

Issue: October 25, 2015

Change in choroidal neovascularization size on indocyanine green angiography can predict recurrent exudation and/or subretinal hemorrhaging after treat-and-extend anti-VEGF therapy for neovascular age-related macular degeneration, according to a study.

Treatment can be extended in cases in which CNV as seen on ICG angiography does not enlarge after anti-VEGF injections, Ryan B. Rush, MD, and colleagues said.

“Changes in the choroidal neovascularization detected with ICG angiography can predict which patients are likely to successfully extend using anti-VEGF therapy in a treat-and-extend protocol,” Rush told Ocular Surgery News. “If that criterion had been used in our study to determine whether the patient could go out longer or not, it would have helped individualize treatment to each particular patient better, giving them less of a chance at their follow-up to come back with retinal exudation or retinal hemorrhaging.”

Methods and measures

The retrospective study, published in Ophthalmic Surgery, Lasers and Imaging Retina, included 141 patients with neovascular AMD who received Avastin (bevacizumab, Genentech) on a treat-and-extend basis for 12 months.

ICG angiography was used to determine CNV size.

Best corrected visual acuity assessment, slit lamp biomicroscopy and OCT imaging were performed at each office visit. Fluorescein angiography and ICG angiography were performed every 8 weeks.

The treat-and-extend regimen comprised a loading dose of three consecutive monthly bevacizumab injections and subsequent monthly injections until the macula was shown to be dry, with no intraretinal or subretinal fluid on OCT or macular hemorrhage on fundus examination.

The initial injection was administered on the baseline examination. Injections were given every 2 weeks until a maximum intervisit interval was reached. The interval was reduced by 2-week increments when retinal edema on OCT recurred, macular hemorrhage recurred or developed on fundus examination, or BCVA decreased by two or more lines.

Outcomes and observations

Treatment was successfully extended beyond 12 weeks for 30 of 141 patients (21.3%). Ninety-one patients (64.5%) were successfully extended to 6 weeks or longer.

“That’s consistent with what other studies have reported, that most patients require ongoing anti-VEGF therapy, often indefinitely. If these patients ever discontinue anti-VEGF therapy, they will eventually return with recurrent hemorrhaging or exudation,” Rush said. “Some patients during the 12-month study interval never achieved a fluid-free macula despite monthly injections. In our study, that number was 22 patients, or about 16%.”

Mean number of bevacizumab injections was 8.2.

Mean BCVA improved significantly from 20/60 at baseline to 20/43 at 12 months (P < .0001). Mean central macular thickness decreased significantly from 386 µm to 309.7 µm (P < .0001).

Final BCVA was 20/152 in the subretinal hemorrhage group, significantly lower than in the overall study population (P < .0001). Final central macular thickness was 404 µm in the subretinal hemorrhage subgroup, significantly worse than in the overall population (P = .0028).

Recurrent exudation was identified in 75.6% of patients after treatment extension at one or more follow-up intervals.

As seen on ICG angiography, CNV size increased 33% or more from week 8 to week 10 in four patients (100%) who failed to extend treatment to 12 weeks. CNV size increased 33% or more from week 8 to week 10 in only five patients (16.7%) who were successfully extended beyond 12 weeks. The difference was statistically significant (P < .0004).

CNV size increased 50% or more right before treatment extension in five of six patients (83.3%) who developed subretinal hemorrhaging. CNV size increased 50% or more before treatment extension in only 13 of 119 patients (10.9%) who did not have subretinal hemorrhaging (P < .0001). – by Matt Hasson

Reference:
Rush RB, et al. Ophthalmic Surg Lasers Imaging Retina. 2015;doi:10.3928/23258160-20150730-05.

For more information:
Ryan B. Rush, MD, can be reached at Southwest Retina Specialists, 7411 Wallace Blvd., Amarillo, TX 79106; email: ryanbradfordrush21@hotmail.com.

Disclosure: Rush reports no relevant financial disclosures.