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Paracentesis before intravitreal injection of bevacizumab
CORRESPONDENCE Paracentesis before intravitreal injection of bevacizumab (Short-term intraocular pressure changes after intravitreal injection of bevacizumab.Vol. 42[6])
Dear Editor,
I
n 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.
Paracentesis before intravitreal injection of bevacizumab—Author reply (Short-term intraocular pressure changes after intravitreal injection of bevacizumab. Vol. 42[6])
Dear Editor,
R
ecent studies have found that IOP increases transiently after intravitreal bevacizumab but returns to a normal level within 5–15 minutes postinjection in most patients.1–3 Tsui et al. have recommended prophylactic paracentesis prior to intravitreal bevacizumab injection in all patients based on 3 factors. First, the immediate IOP rise seen in most patients may damage small ocular vessels, potentially aggravating an already impaired blood–retinal barrier in diabetic or venous occlusive eyes. Second, paracentesis would prevent drug reflux, resulting in more medication entering the vitreous cavity. In addition, they feel that paracentesis carries minimal risk of infection and lens damage. We agree with Tsui et al. that a cautious approach is
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. REFERENCES 1. Hollands H, Wong J, Bruen R, Campbell RJ, Sharma S, Gale J. Short-term intraocular pressure changes after intravitreal injection of bevacizumab. Can J Ophthalmol 2007;42:807–11. 2. Bakri SJ, Pulido JS, McCannel CA, Hodge DO, Diehl N, Hillemeier J. Immediate intraocular pressure changes following intravitreal injections of triamcinolone, pegaptanib, and bevacizumab. Eye 2007. [Epub ahead of print.] 3. Falkenstein IA, Cheng L, Freeman WR. Changes of intraocular pressure after intravitreal injection of bevacizumab (Avastin). Retina 2007;27:1044–7.
Yung-Ping Tsui, Chun-Chi Chiang, Yi-Yu Tsai China Medical University Hospital, Taichung, Taiwan Correspondence to Yi-Yu Tsai, MD: [email protected] Can J Ophthalmol 2008;43:239 doi:10.3129/i08-033
prudent in patients at risk for mechanical blood flow compromise to the retina or optic nerve head. Our study showed that at 2 minutes after bevacizumab injection, 12.5% of patients had an IOP greater than 50 mm Hg, with the average IOP being 36 mm Hg.3 The clinical consequences of this are unknown, but may certainly include inducing ocular perfusion pressure below the optic nerve head blood flow autoregulatory range.4 Based on our clinical experience of over 5000 intravitreal injections, however, we do not believe that drug reflux occurs to any significant degree after injection of 0.05 cc in patients with a normal baseline IOP. Furthermore, the incremental risk of lens damage and infection from an additional needle poke for paracentesis is not trivial. In conclusion, although the consequences of a transient IOP spike after intravitreal injection are unknown, we feel that in general the risks of prophylactic paracentesis outweigh the benefits. For patients at high risk for pressureinduced complications such as those with advanced glaucoma or macular ischemia, a prophylactic paracentesis may be worth considering. CAN J OPHTHALMOL—VOL. 43, NO. 2, 2008
239
Dear Editor,
I
n 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.
Paracentesis before intravitreal injection of bevacizumab—Author reply (Short-term intraocular pressure changes after intravitreal injection of bevacizumab. Vol. 42[6])
Dear Editor,
R
ecent studies have found that IOP increases transiently after intravitreal bevacizumab but returns to a normal level within 5–15 minutes postinjection in most patients.1–3 Tsui et al. have recommended prophylactic paracentesis prior to intravitreal bevacizumab injection in all patients based on 3 factors. First, the immediate IOP rise seen in most patients may damage small ocular vessels, potentially aggravating an already impaired blood–retinal barrier in diabetic or venous occlusive eyes. Second, paracentesis would prevent drug reflux, resulting in more medication entering the vitreous cavity. In addition, they feel that paracentesis carries minimal risk of infection and lens damage. We agree with Tsui et al. that a cautious approach is
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. REFERENCES 1. Hollands H, Wong J, Bruen R, Campbell RJ, Sharma S, Gale J. Short-term intraocular pressure changes after intravitreal injection of bevacizumab. Can J Ophthalmol 2007;42:807–11. 2. Bakri SJ, Pulido JS, McCannel CA, Hodge DO, Diehl N, Hillemeier J. Immediate intraocular pressure changes following intravitreal injections of triamcinolone, pegaptanib, and bevacizumab. Eye 2007. [Epub ahead of print.] 3. Falkenstein IA, Cheng L, Freeman WR. Changes of intraocular pressure after intravitreal injection of bevacizumab (Avastin). Retina 2007;27:1044–7.
Yung-Ping Tsui, Chun-Chi Chiang, Yi-Yu Tsai China Medical University Hospital, Taichung, Taiwan Correspondence to Yi-Yu Tsai, MD: [email protected] Can J Ophthalmol 2008;43:239 doi:10.3129/i08-033
prudent in patients at risk for mechanical blood flow compromise to the retina or optic nerve head. Our study showed that at 2 minutes after bevacizumab injection, 12.5% of patients had an IOP greater than 50 mm Hg, with the average IOP being 36 mm Hg.3 The clinical consequences of this are unknown, but may certainly include inducing ocular perfusion pressure below the optic nerve head blood flow autoregulatory range.4 Based on our clinical experience of over 5000 intravitreal injections, however, we do not believe that drug reflux occurs to any significant degree after injection of 0.05 cc in patients with a normal baseline IOP. Furthermore, the incremental risk of lens damage and infection from an additional needle poke for paracentesis is not trivial. In conclusion, although the consequences of a transient IOP spike after intravitreal injection are unknown, we feel that in general the risks of prophylactic paracentesis outweigh the benefits. For patients at high risk for pressureinduced complications such as those with advanced glaucoma or macular ischemia, a prophylactic paracentesis may be worth considering. CAN J OPHTHALMOL—VOL. 43, NO. 2, 2008
239