Old vs new

New research is questioning the wisdom of switching anti-vascular endothelial growth factor (anti-VEGF) medications if a patient’s vision does not respond well to treatment in the first few months.

Clinicians treating patients with wet age-related macular degeneration or diabetic macular oedema with an anti-VEGF drug can commonly switch to another form if the person’s vision does not show improvement.

However, in a paper published in the journal JAMA Ophthalmology, US researchers wrote that, as yet, noone has looked at what happens if a patient continues with the original treatment past the point when a switch might be deemed appropriate.

To remedy this, the team analysed the data of patients treated with two anti-VEGF therapies, bevacizumab (Avastin) or ranibizumab (Lucentis), and selected a group of patients that met ‘switching criteria’ that the researchers had pre-determined.

Then, instead of being switched to an alternate medication, these patients continued with the same treatment. In the three months following the point at which they might have been switched, patients recorded a three- to five-letter improvement on visual acuity tests.

Central retinal thickness also showed improvement during this period, nearly doubling from an average 40 nanometres to 70 nanometres.

In their conclusion, the paper authors wrote that: “These results demonstrate the importance of having a comparison group to evaluate the effect of switching anti-VEGF agents for treatment.”