Does bevacizumab (Avastin) improve visual acuity and reduce choroidal thickness?

Bevacizumab Improves Visual Acuity and Reduces Choroidal Thickness

Bevacizumab (Avastin) effectively improves visual acuity and reduces both retinal thickness and subfoveal choroidal thickness in patients with neovascular age-related macular degeneration and diabetic macular edema.

Visual Acuity Improvement

Bevacizumab consistently demonstrates significant visual acuity gains across multiple studies:

• Mean visual acuity improved from 20/200 to 20/125 at 4 and 8 weeks after intravitreal bevacizumab injection (1.25 mg), with median vision reaching 20/80 1
• At 6 months follow-up, mean logMAR vision improved from 0.84 to 0.74 (P<0.05), with sustained improvement to 0.69 at 9 months 2
• In a prospective randomized trial, bevacizumab-treated eyes gained an average of 7.6 letters (from 34.9 to 42.5 letters) at 1 year, with no statistical difference compared to ranibizumab 3
• Visual improvement occurred in both treatment-naïve and previously treated patients, with final mean visual acuity improving from 20/125 to 20/100 (P=0.03) 4

Retinal Thickness Reduction

The anatomic response to bevacizumab is rapid and substantial:

• Central retinal thickness decreased by 61 μm at 1 week, 92 μm at 4 weeks, 89 μm at 8 weeks, and 67 μm at 12 weeks (all P<0.01) 1
• Mean central macular thickness reduced from 362 μm at baseline to 278 μm at 1 week (P=0.001), 235 μm at 1 month (P<0.0001), and 244 μm at final follow-up 4
• Complete resolution of retinal edema, subretinal fluid, and pigment epithelial detachments occurred in 30 of 81 eyes (37%) at 4 weeks and 25 of 51 eyes (49%) at 8 weeks 1
• Mean foveal thickness decreased from 291 μm to 282.7 μm at 3 months (P<0.05) and 249.7 μm at 6 months (P<0.05) 2

Choroidal Thickness Reduction

Bevacizumab produces a significant and measurable reduction in subfoveal choroidal thickness:

• Mean subfoveal choroidal thickness decreased from 237.1 μm at baseline to 214.0 μm at day 1,205.4 μm at week 1 (maximum effect), and 222.7 μm at month 1 in treated eyes 5
• The decreasing effect on choroidal thickness was highest at the first week and continued through the first month after injection 5
• This choroidal thinning occurred in both neovascular AMD and diabetic macular edema patients, demonstrating a consistent anti-VEGF effect on choroidal vasculature 5
• Fellow untreated eyes showed minimal change in choroidal thickness (228.4 μm to 226.9 μm), confirming the local treatment effect 5

Treatment Considerations

Dosing typically involves 1.25 mg intravitreal injections, with most patients requiring multiple treatments:

• Average of 3.3 injections per eye over approximately 4.5 months of follow-up 4
• Initial monthly dosing for 3 months followed by OCT-guided variable dosing is effective 3
• Previously treated patients respond similarly to treatment-naïve patients, with no significant difference in outcomes (P=0.62 for OCT, P=0.28 for visual acuity) 4

Safety Profile

Bevacizumab is generally well-tolerated with rare serious adverse events:

• Reported complications include endophthalmitis (1 case), retinal pigment epithelial tears (3 cases), and submacular hemorrhages (3 cases) in a series of 112 eyes 2
• No significant systemic or ocular adverse events were recorded in the 54-eye series with mean 138 days follow-up 4
• No significant ocular or systemic side effects were observed in the initial 81-eye series 1