OCT 13, 2012
This article presents a series of previously normotensive eyes with sustained elevated IOP associated with long-term intravitreal antivascular endothelial growth factor (anti-VEGF) therapy for wet AMD. While many anecdotal cases of IOP elevation following intravitreal injections have been reported, this large study in the April/May 2012 issue of the Journal of Glaucoma provides an excellent overview and discussion about the possible mechanisms of this effect and the timing of treatment.
The study included 23 patients with wet AMD who experienced increased IOP while receiving interval doses of intravitreal ranibizumab and/or bevacizumab. All of these eyes previously had tolerated multiple anti-VEGF injections without IOP elevations. The patients were followed for a mean of 47.9 weeks after the initial detection of elevated IOP.
After a mean of 20 anti-VEGF injections, the mean IOP was 29.8 mmHg, compared with a baseline of 16.9 mmHg. The mean highest IOP while receiving intravitreal anti-VEGF therapy was 35.8 mmHg.
Twenty-three eyes required IOP management. In the remaining two cases, the patients were switched from regular anti-VEGF interval dosing to an OCT-guided variable regimen. IOP subsequently improved without anti-glaucoma treatment, and no further anti-VEGF therapy was needed during the follow-up period. Four other eyes treated with topical therapy for IOP elevations were also switched to an OCT-guided PRN dosing regimen. Only one of these eyes required an additional intravitreal anti-VEGF injection, and IOP stabilized or improved in the remaining three eyes.
The authors conclude that these findings suggest at least some reversibility of treatment-related IOP elevations after cessation of anti-VEGF therapy.
Although cases of sustained ocular hypertension following repeated intravitreal anti-VEGF injection may represent fewer than 5 to 10 percent of all eyes receiving treatment, they say continued injections may cause further increases in IOP. This may lead to treatment with multiple topical antiglaucoma agents and, in some eyes, laser trabeculoplasty and/or glaucoma filtration surgery.
They conclude that in appropriate cases, switching to an OCT-guided as-needed dosing regimen may help reduce the risk of further IOP elevation by decreasing the frequency of intravitreal anti-VEGF injection.