Intravitreal Injections: Postinjection Endophthalmitis Rates
Intravitreal Injections: Postinjection Endophthalmitis Rates
Aim To report the incidence rate of acute postoperative endophthalmitis secondary to therapeutic intravitreal injections.
Methods A retrospective review of all consecutive eyes after intravitreal injections was performed at the Massachusetts Eye and Ear Infirmary, Boston, from 1 January 2007 to 31 December 2011.
Results During the 5-year study interval, 10 208 intravitreal injections were performed. The overall incidence rate of endophthalmitis was 0.029% per injection (3 of 10 208 injections). In the three cases, in our series, the endophthalmitis occurred at an average of seven injections, which lies within the SD of the mean number of injections received by each eye in this study, suggesting approximately equal probability of infection for each eye after receiving multiple, sequential injections. Bacterial cultures and Gram stain revealed coagulase-negative Staphylococcus species (n=1), moderate bacteria with negative culture (n=1) and moderate Staphylococcus epidermidis (n=1). All cases were successfully treated using either intravitreal antibiotics and steroids or pars plana vitrectomy. Best-corrected visual acuity reduction was not clinically significant at the last visit (>7 months for all cases).
Conclusions Acute endophthalmitis is a rare potential complication after intravitreal injection. Further studies are required to elucidate the best prophylactic and aseptic techniques to prevent this rare complication.
Intravitreal injections of pharmacological agents for the treatment of various retinal and choroidal diseases have dramatically increased over the past decade. The rapid increase in clinical use of intravitreal injections has largely been due to the development of new pharmacological agents, in particular drugs such as ranibizumab and bevacizumab directed against vascular endothelial growth factor (VEGF). Other medications for intravitreal use included steroids, antiviral agents and antibiotics. These agents are used to treat choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD) as well as other pathology, including proliferative diabetic retinopathy, diabetic macular oedema (DMO), neovascular glaucoma (NVG), uveitis, bacterial endophthalmitis and cytomegalovirus (CMV) retinitis. Treatment may frequently require repeated injections.
The substantial growth in intravitreal injections has led to the concern regarding the risk of endophthalmitis following this procedure. According to Medicare records, there has been a marked increase in the use of intravitreal injections in the treatment of neovascular AMD since 2001. Fewer than 5000 intravitreal injections of a pharmacological agent were performed annually between 1997 and 2001. Since then, their use has increased 193-fold from 4215 injections in 2001 to 812 413 injections in 2007. To date, multicentre clinical trials and retrospective case series suggest that intravitreal injections are associated with a low risk of endophthalmitis ranging from 0.02% to 1.6% per injection. Bacterial infections are the most common cause of postinjection endophthalmitis. The ocular surface and the adnexa are considered the primary sources of infection. However, contaminated agents or surgical equipment used perioperatively should be considered as well. Multiple studies indicate that coagulase-negative staphylococci are the most common isolated pathogen in postoperative endophthalmitis. Less common organisms include Streptobacillus parasanguis, Mycobacterium chelonae and Streptobacillus species. Intravitreal injections have been associated with non-infectious (sterile) endophthalmitis as well, particularly in the context of intravitreal triamcinolone acetonide injections.
Despite the growing number of indications and agents for intravitreal injections, there is no consensus on peri-injection guidelines for the prophylaxis of endophthalmitis. Currently, the use of preinjection and postinjection antibiotics varies greatly, has changed over time and remains controversial. In this retrospective review, we report the incidence of endophthalmitis after intravitreal injections of pharmacological agents in a large academic centre, where multiple practitioners employ various intravitreal injection protocols.
Abstract and Introduction
Abstract
Aim To report the incidence rate of acute postoperative endophthalmitis secondary to therapeutic intravitreal injections.
Methods A retrospective review of all consecutive eyes after intravitreal injections was performed at the Massachusetts Eye and Ear Infirmary, Boston, from 1 January 2007 to 31 December 2011.
Results During the 5-year study interval, 10 208 intravitreal injections were performed. The overall incidence rate of endophthalmitis was 0.029% per injection (3 of 10 208 injections). In the three cases, in our series, the endophthalmitis occurred at an average of seven injections, which lies within the SD of the mean number of injections received by each eye in this study, suggesting approximately equal probability of infection for each eye after receiving multiple, sequential injections. Bacterial cultures and Gram stain revealed coagulase-negative Staphylococcus species (n=1), moderate bacteria with negative culture (n=1) and moderate Staphylococcus epidermidis (n=1). All cases were successfully treated using either intravitreal antibiotics and steroids or pars plana vitrectomy. Best-corrected visual acuity reduction was not clinically significant at the last visit (>7 months for all cases).
Conclusions Acute endophthalmitis is a rare potential complication after intravitreal injection. Further studies are required to elucidate the best prophylactic and aseptic techniques to prevent this rare complication.
Introduction
Intravitreal injections of pharmacological agents for the treatment of various retinal and choroidal diseases have dramatically increased over the past decade. The rapid increase in clinical use of intravitreal injections has largely been due to the development of new pharmacological agents, in particular drugs such as ranibizumab and bevacizumab directed against vascular endothelial growth factor (VEGF). Other medications for intravitreal use included steroids, antiviral agents and antibiotics. These agents are used to treat choroidal neovascularisation (CNV) due to age-related macular degeneration (AMD) as well as other pathology, including proliferative diabetic retinopathy, diabetic macular oedema (DMO), neovascular glaucoma (NVG), uveitis, bacterial endophthalmitis and cytomegalovirus (CMV) retinitis. Treatment may frequently require repeated injections.
The substantial growth in intravitreal injections has led to the concern regarding the risk of endophthalmitis following this procedure. According to Medicare records, there has been a marked increase in the use of intravitreal injections in the treatment of neovascular AMD since 2001. Fewer than 5000 intravitreal injections of a pharmacological agent were performed annually between 1997 and 2001. Since then, their use has increased 193-fold from 4215 injections in 2001 to 812 413 injections in 2007. To date, multicentre clinical trials and retrospective case series suggest that intravitreal injections are associated with a low risk of endophthalmitis ranging from 0.02% to 1.6% per injection. Bacterial infections are the most common cause of postinjection endophthalmitis. The ocular surface and the adnexa are considered the primary sources of infection. However, contaminated agents or surgical equipment used perioperatively should be considered as well. Multiple studies indicate that coagulase-negative staphylococci are the most common isolated pathogen in postoperative endophthalmitis. Less common organisms include Streptobacillus parasanguis, Mycobacterium chelonae and Streptobacillus species. Intravitreal injections have been associated with non-infectious (sterile) endophthalmitis as well, particularly in the context of intravitreal triamcinolone acetonide injections.
Despite the growing number of indications and agents for intravitreal injections, there is no consensus on peri-injection guidelines for the prophylaxis of endophthalmitis. Currently, the use of preinjection and postinjection antibiotics varies greatly, has changed over time and remains controversial. In this retrospective review, we report the incidence of endophthalmitis after intravitreal injections of pharmacological agents in a large academic centre, where multiple practitioners employ various intravitreal injection protocols.