Comparison of Intravitreal Ziv-aflibercept and Bevacizumab in the Treatment of Macular Edema Secondary to Central Retinal Vein Occlusion: A Prospective Study

Introduction

– Macular edema (ME) is a common complication of central retinal vein occlusion (CRVO)
– Vascular endothelial growth factor (VEGF) plays a key role in the pathogenesis of ME secondary to CRVO
– Aflibercept is considered the first choice of treatment for visual improvement
– A recent study suggests that bevacizumab is not inferior to aflibercept in visual improvement but requires more injections.
– Aflibercept is expensive, so bevacizumab is the first-line treatment in real-world practice.
– Ziv-aflibercept is a cheaper alternative with the same molecular structure and mechanism of action as aflibercept.

Patients and Methods

– This prospective, double-blind, randomized controlled trial compared intravitreal ziv-aflibercept (IVZ) and intravitreal bevacizumab (IVB)
– Patients with ME secondary to CRVO were recruited
– Inclusion criteria: age >45 years, diagnosis of CRVO with center-involved ME, and central subfield thickness (CST) >300 µm confirmed by spectral-domain optical coherence tomography (SD-OCT)
– Exclusion criteria: one-eyed patients, bilateral CRVO, autoimmune disorders, ocular infections, previous ocular surgeries, and more

Randomization and Masking Procedures

– Participants were randomly assigned to receive either IVZ or IVB
– Randomization was done using a variable block randomization generator
– The allocation sequence was concealed in a sealed opaque envelope
– Researchers, patients, technicians, and evaluators were blinded to the treatment codes

Surgical Procedures

– All patients underwent standard intravitreal injections performed by a single surgeon
– Three monthly loading injections were given, followed by a pro-re-nata (PRN) protocol
– Reinjections were given based on recurrence or persistent ME with CST >300 µm
– Ziv-aflibercept 1.25 mg/0.05 mL or bevacizumab 1.25 mg/0.05 mL was injected posterior to the superotemporal limbus

Patient Evaluation and Outcome Measures

– Demographic data, ophthalmic examinations, and outcomes were recorded
– Primary outcomes: best-corrected visual acuity (BCVA) and CST
– Secondary outcomes: number of injections and adverse events

Statistical Analysis

– The estimated sample size required was 17 eyes per group
– Equivalence and superiority were considered positive outcomes
– Analyses were performed using Stata version 16.1
– Statistical significance was set at p <0.05

Results

– 24 patients were enrolled in the study
– Majority of patients (58.33%) were female
– Mean age of patients was 57.15 ± 7.65 years
– Mean duration of symptoms was 1.86 ± 1.77 months
– Mean initial BCVA was 1.18 ± 0.60 logMAR
– Mean baseline CST was 746.17 ± 264.95 µm
– Cystoid macular edema was found in all studied eyes, while subfoveal serous macular detachment was present in half of the cases

Conclusion

– The study aimed to compare the efficacy of IVZ and IVB in patients with ME secondary to CRVO
– Results and conclusions of the study are pending and will be reported upon completion of the 6-month follow-up period.