Anti-VEGF Intravitreal Injections Are the Clear Standard of Care
Anti-VEGF intravitreal injections (ranibizumab, bevacizumab, or aflibercept) are the established standard of care for neovascular age-related macular degeneration and diabetic macular edema, while DMSO drops have no recognized role in treating these vision-threatening conditions. DMSO drops are not mentioned in any major ophthalmology guidelines and lack evidence for efficacy in retinal vascular diseases 1.
Evidence-Based Treatment Recommendations
For Diabetic Macular Edema (DME)
Intravitreal anti-VEGF agents are the standard of care for center-involving DME with vision loss (20/30 or worse) 1. The International Council of Ophthalmology explicitly states that intravitreal anti-VEGF administration "has been demonstrated to be the standard of care with favorable outcomes in preventing vision loss in patients with DME" 1.
Drug Selection for DME:
- For baseline vision 20/50 or worse: Aflibercept 2 mg provides superior visual outcomes at 1 year, though ranibizumab achieves similar results by 2 years 1
- For baseline vision 20/40 or better: All three agents (aflibercept, ranibizumab, bevacizumab) provide similar visual outcomes 1
- Bevacizumab 1.25 mg is less effective at reducing retinal thickening compared to aflibercept or ranibizumab, though it provides similar visual outcomes in mild visual impairment 1
For Neovascular Age-Related Macular Degeneration (AMD)
Anti-VEGF therapy is safe and effective for neovascular AMD, with multiple agents demonstrating substantial visual benefits 1. The American Academy of Ophthalmology's Preferred Practice Pattern confirms anti-VEGF injections as first-line therapy 1.
Comparative Efficacy:
- Bevacizumab and ranibizumab show equivalent efficacy when using treat-and-extend protocols, with mean gains of 7.4 and 6.6 letters respectively at 2 years 2
- Brolucizumab (FDA-approved October 2019) achieved superior reductions in central subfield thickness compared to aflibercept 1
- Monthly or treat-and-extend regimens maintain better long-term visual gains than PRN (as-needed) dosing 1
Dosing Strategies
The treat-and-extend protocol is widely used in clinical practice and demonstrates comparable efficacy to monthly dosing with fewer injections 1, 2. This involves:
- Initial monthly injections until inactive disease is achieved 2
- Extending treatment intervals by 2 weeks at a time up to maximum 12 weeks 2
- Shortening intervals by 2 weeks if recurrence occurs 2
Caution with PRN bevacizumab: PRN dosing of bevacizumab may be slightly less effective than other monthly anti-VEGF regimens 1.
Safety Profile
Anti-VEGF injections carry well-characterized risks 1:
- Endophthalmitis: 0.16% for bevacizumab, ≤1.0% for ranibizumab and aflibercept 1
- Retinal detachment, uveitis, vitreous hemorrhage: <0.2% each 1
- Systemic events: Bevacizumab shows higher rates of serious systemic adverse events (24% vs 19% for ranibizumab, P=0.04) 1
- Plasma VEGF suppression: Bevacizumab significantly reduces plasma VEGF levels for up to one month, while ranibizumab and pegaptanib do not 3
Why DMSO Drops Are Not Appropriate
DMSO (dimethyl sulfoxide) drops are not recognized in any ophthalmology guidelines for treating retinal vascular diseases 1. The pathophysiology of neovascular AMD and DME involves VEGF-driven angiogenesis and vascular permeability, which requires direct intravitreal delivery of anti-VEGF agents to achieve therapeutic intraocular concentrations 4, 5, 6. Topical drops cannot achieve adequate retinal drug levels for these posterior segment diseases.
Common Pitfalls to Avoid
- Do not delay anti-VEGF therapy in center-involving DME with vision loss—refer within 1 month 1
- Avoid PRN dosing with bevacizumab as it may be less effective than other regimens 1
- Do not assume all anti-VEGF agents are equivalent in eyes with worse baseline vision (20/50 or worse)—aflibercept shows superior 1-year outcomes 1
- Monitor for endophthalmitis after every injection, as this is the most serious complication 1