Background: The use of intravitreal anti-VEGF agents in general, and of bevacizumab (Avastin) in particular, has become the common first-line treatment of neovascular age-related macular degeneration (AMD). Several reports addressed the possible elevation of intraocular pressure (IOP) following intravitreal injection of anti-VEGF. The aim of this study was to determine the prevalence of sustained IOP elevation following intravitreal bevacizumab injections for neovascular AMD and identify possible risk factors for the development of increased IOP.
Methods: This retrospective cohort study included 174 consecutive patients (201 eyes) receiving intravitreal bevacizumab (1.25 mg/0.05 ml) as treatment for neovascular AMD. The records of the study patients were reviewed for age, gender, history of glaucoma, phakic status, IOP levels, length of follow-up, total number of injections, intervals between injections, and IOP management in eyes that exhibited IOP elevation. Sustained IOP elevation was defined as IOP ≥22 mmHg and a change from baseline of ≥6 mmHg recorded on at least two consecutive visits and lasting ≥30 days. Risk factors for an IOP increase were identified from the association between the studied variables and IOP elevations.
Results: Sustained IOP elevation was found in 22 of 201 eyes (11%). The increased IOP was controlled with topical medications in all eyes. Among the variables studied, only male gender [OR = 3.1, 95% CI (1.1, 8.5) p = 0.029] and length of interval between injections <8 weeks [OR = 3.0, 95%CI (1.1, 7.9), p = 0.028] emerged as risk factors for IOP elevation in a multivariable model. The prevalence of IOP elevation was significantly higher when the interval between injections was <8 weeks than ≥8 weeks (17.6 and 6%, respectively, p = 0.009). Pre-existing glaucoma was not associated with IOP elevation (p = 0.9).
Conclusions: Sustained IOP elevations can occur in normotensive eyes undergoing intravitreal bevacizumab treatment for neovascular AMD. This phenomenon was related to shorter intervals between injections, with 8 weeks being taken as the cut-off point. AMD eyes that receive intravitreal bevacizumab injections need to be monitored for IOP changes, especially those in which the intervals between injections are <8 weeks.