Abstract
Purpose: :
Intravitreal injections are becoming increasingly widespread for treating age-related macular degeneration (AMD). Some concern has been raised about subsequent acute elevation of intraocular pressure (IOP) in the injected eye. The most frequently used injected drugs are ranibizumab (Lucentis) and bevacizumab (Avastin). One retrospective study found elevations in IOP immediately after the injection of various medications (ranibizumab, bevacizumab, pegaptanib, triamcinolone), with normalization to <30 mmHg by 30 minutes. Each drug, however, had different pharmacologic properties and a different volume of the injected drug, which might have affected the results. Clinical trials on ranibizumab have shown increased IOP during the first hour post injection. Another study on bevacizumab reported an acute elevation in IOP immediately after injection and an IOP <30 mmHg 15 minutes after the injection. However, IOP had been measured with the Goldman applanation before the injection and with the TonoPen afterwards. TonoPen measurements may have underestimated the IOP at the upper extremes of pressure. Our study used only Goldmann tonometry before and after injections of bevacizumab to evaluate shortterm IOP changes and to plan an appropriate post injection management of these patients accordingly.
Methods: :
Ninety eyes (90 patients) undergoing intravitreal bevacizumab injection (1.25 mg/0.05 ml) for treating AMD were included. The number of past injections was recorded. IOP was measured before, immediately after and 30 minutes following the index injection. Injected eyes were evaluated for vitreal fluid reflux and axial length.
Results: :
The average IOP was 16.9±4.2 mmHg prior to injection, 33.9±12.2 mmHg (p<0.001) immediately after injection and 17.9±4.7mmHg at 30 minutes after injection. IOP was significantly higher immediately after injection in 43 eyes without reflux (42.8±11.6 mmHg) and their IOP elevation correlated with higher baseline IOPs (r=.634, p<0.001). Forty seven eyes with vitreal reflux showed only a moderate post injection IOP elevation (25.7±5.2 mmHg). Multiple injections and axial length did not correlate with IOP elevation in this group of patients.
Conclusions: :
IOP monitoring for normalization after intravitreal bevacizumab injections is apparently not necessary for most eyes on the day of injection. Judicious IOP monitoring post injection may be needed when there is no reflux and for patients with higher pre injection IOP.
Keywords: age-related macular degeneration • intraocular pressure • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials