Treat-and-Extend Regimen Viable In Treatment Of Macular Edema Secondary To RVO

Varun Chaudhary, MD

Due to shortcomings associated with the pro re nata (PRN) approach in the treatment of retinal vein occlusions (RVOs), including destabilization of the disease, the treat-and-extend regimen was developed to address regimental limitations.

However, a lack of evidence on the ideal treatment regimen led to a recent study, which assessed the efficacy of treat-and-extend anti-VEGF therapies for the treatment of macular edema secondary to RVOs.

Led by Varun Chaudhary, MD, Hamilton Regional Eye Institute, St. Joseph’s Healthcare Hamilton King Campus, a team of investigators observed treat-and-extend regimens supported treatment protocol for macular edema secondary to RVOs, without the treatment burden of monthly assessments.

Methods

Chaundhary and colleagues searched the Ovid MEDLINE, Ovid EMBASE, and CENTRAL were searched in February 2021.

They included data from studies examining the use of anti-VEGF therapy for treatment of macular edema associated with RVO in a T&E dosing regimen, including randomized controlled trials, cohort studies, case-control studies, and case series.

The primary outcome was considered the change in Early Treatment Diabetic Retinopathy Score (ETDRS) letters from baseline. If studies reported Snellen, data was converted to ETDRS using a published protocol.

Investigators extracted data on best-corrected visual acuity (BCVA), anatomic outcomes, number of intravitreal injections (IVIs), number of clinic visits, and serious adverse events. Outcomes were measured at the 12-month and 24-month time points.

They assessed the certainty of evidence utilizing the Grading of Recommendations Assessments, Development, and Evaluations (GRADE) guidelines.

Findings

A total of 377 full texts were reviewed and of these, 16 were included in the analysis. The total population included 786 eyes from 784 patients, with a mean age of 73.9 years and 54% were male. The anti-VEGF agent aflibercept was utilized more frequently, followed by ranibizumab and bevacizumab.

The meta-analysis demonstrated a mean improvement of 15.7 (95% CI, 13.3 - 18.0, I² = 83%) ETDRS letters from baseline at 12 months.

A subgroup analysis showed the heterogeneity was in-part explained by drug type, duration of loading phase (≤3 months and >3 months), location of RVO and treatment naive status.

Data show studies with loading phases >3 months had a greater improvement at 12 months compared to studies with loading phases ≤3 months (20.5; 95% CI, 17.7 - 23.3 versus 15.0; 95% CI, 12.3 - 17.6)

Then, at 12 months, a total of 6 studies reported central retinal thickness (CRT) improved 269.7 μm (95% CI, 233.64 - 305.90, I² = 99%) at 12 months.

Studies with loading phases >3 months showed greater improvement in CRT compared to studies with loading phases ≤3 months (48.13 μm, 95% CI, 439.7 - 522.9 versus 25.1 μm, 95% CI, 221.6 - 280.6).

Additionally, at 12 months, central macular thickness (CMT) improved 285.1 μm (95% CI, 201.3 - 368.9, I² = 94%) in 3 studies, while central subfield thickness (CST) was reported 342.9 μm (95% CI, 280.0 - 405.8,  I² = 83%).

Further, at 12 months, IVI was performed 8.1 times (95% CI, 7.4 - 8.7, I2 = 97%) at 12 months and 13.1 times (95% CI, 9.4 - 16.8, I² = 98%).

Investigators observed low frequency of adverse events and a low GRADE certainty of evidence across all outcomes.

Takeaways

“Our results suggest that treat-and-extend regimens can reduce the frequency of patient visits and injections compared to fixed regimens while still improving functional and anatomic outcomes,” investigators wrote.

“Treat-and-extend regimens of anti-vascular endothelial growth factor therapy for retinal vein occlusions: a systematic review and meta-analysis,” was published in Acta Ophthalmologica.