Paracentesis before intravitreal injection of bevacizumab

Abstract

In their article, Hollands et al.1 evaluated the short-term intraocular pressure (IOP) changes after intravitreal injection of bevacizumab (Avastin, Genentech Inc, San Francisco, Calif.). They reported that elevated IOP after 30 minutes of observation might occur in a small number of patients, and that clinicians should consider checking IOP after injection as a precaution or should perform a preinjection paracentesis as prophylaxis.1 There are some points that we would like to add in the case of paracentesis. There are 2 other papers that discuss IOP changes following intravitreal bevacizumab and the need for paracentesis.2,3 In the series of Bakri et al.,2 no patients required paracentesis, but some required IOP-lowering drops. Falkenstein et al.3 reported that all eyes in their series had an IOP below 30 mm Hg after 15 minutes, making paracentesis unnecessary. The need for preinjection paracentesis is controversial according to IOP changes; however, we still recommend the importance of paracentesis before injection based on the following facts. An intravitreal injection of 0.05–0.1 cc bevacizumab will result in immediate IOP rise without paracentesis, even though IOP will normalize several minutes later, whether spontaneously, due to IOP-lowering drops, or after postinjection paracentesis. The sudden IOP rise (usually >40 mm Hg) can damage delicate retinal structures, especially the optic nerve and the small vessels of the retina and the choroid, which may aggravate the original impaired blood–retinal barrier in diabetic or venous occlusive eyes. Although immediate postinjection paracentesis can reduce IOP, there is still some potential for damage, especially when performed repeatedly. Another complication is drug reflux during injection, due to a sudden rise in IOP. Although procedure entails applying several seconds of pressure to the injection site with a sterile cotton-tipped applicator, reflux can still occur. Preinjection paracentesis can prevent the reflux, ensuring that the complete dose of bevacizumab remains in the vitreous cavity. It is true that paracentesis carries the risks of infection and lens damage; however, none of our more than 300 patients undergoing intravitreal bevacizumab injection with preinjection paracentesis have developed endophthalmitis or lens damage. The incidence of these complications is low when caution is used at the time of procedure.