Acute endophthalmitis following intravitreal bevacizumab (Avastin) injection

Deferasirox nanosuspension loaded dissolving microneedles for ocular drug delivery

Deferasirox (DFS) is an oral iron chelator that is employed in retinal ailments as a neuroprotectant against retinal injury and thus has utility in treating disorders such as excitoneurotoxicity and age-related macular degeneration (AMD). However, the conventional oral route of administration can present several disadvantages, e.g., the need for more frequent dosing and the first-pass effect. Microneedles (MNs) are minimally invasive systems that can be employed for intrascleral drug delivery without pain and can advantageously replace intravitreal injections therapy (IVT) as well as conventional oral routes of delivery for DFS. In this study, DFS was formulated into a nanosuspension (NS) through wet media milling employing PVA as a stabilizer, which was successfully loaded into polymeric dissolving MNs. DFS exhibited a 4-fold increase in solubility in DFS-NS compared to that of pure DFS. Moreover, the DFS-NSs exhibited excellent short-term stability and enhanced thermal stability, as confirmed through thermogravimetric analysis (TGA) studies. The mechanical characterization of the DFS-NS loaded ocular microneedles (DFS-NS-OcMNs), revealed that the system was sufficiently strong for effective scleral penetration. Optical coherence tomography (OCT) images confirmed the insertion of 81.23 ± 7.35 % of the total height of the MN arrays into full-thickness porcine sclera. Scleral deposition studies revealed 64 % drug deposition after just 5 min of insertion from DFS-NS-loaded ocular microneedles (OcMNs), which was almost 5 times greater than the deposition from pure DFS-OcMNs. Furthermore, both DFS and DFS-NS-OcMN exhibited remarkable cell viability when evaluated on human retinal pigment (ARPE) cells, suggesting their safety and appropriateness for use in the human eye. Therefore, loading DFS-NS into novel MN devices is a promising technique for effectively delivering DFS to the posterior segment of the eye in a minimally invasive manner.

Monoclonal antibodies in diabetic retinopathy

INTRODUCTION

Diabetic retinopathy (DR), as one of the main complications of diabetes, is among the leading causes of blindness and visual impairment worldwide.

AREAS COVERED

Current clinical therapies include photocoagulation, vitrectomy, and anti-vascular endothelial growth factor (VEGF) therapies. Bevacizumab and ranibizumab are two monoclonal antibodies (mAbs) inhibiting angiogenesis. Intravitreal ranibizumab and bevacizumab can decrease the rate of blindness and retinal thickness, and improve visual acuity whether as monotherapy or combined with other treatments. They can increase the efficacy of other treatments and decrease their adverse events. Although administered intravitreally, they also might enter the circulation and cause systemic effects. This study is aimed to review our current knowledge about mAbs, bevacizumab and ranibizumab, in DR including superiorities, challenges, and limitations. Meanwhile, we tried to shed light on new ideas to overcome these limitations. Our latest search was done in April 2021 mainly through PubMed and Google Scholar. Relevant clinical studies were imported.

EXPERT OPINION

Future direction includes detection of more therapeutic targets considering other components of DR pathophysiology and shared pathogenesis of DR and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease, the treat-and-extend regimen, and new ways of drug delivery and other routes of ocular drug administration.

Spermine oxidase: A promising therapeutic target for neurodegeneration in diabetic retinopathy

Diabetic Retinopathy (DR), is a significant public health issue and the leading cause of blindness in working-aged adults worldwide. The vision loss associated with DR affects patients' quality of life and has negative social and psychological effects. In the past, diabetic retinopathy was considered as a vascular disease; however, it is now recognized to be a neuro-vascular disease of the retina. Current therapies for DR, such as laser photocoagulation and anti-VEGF therapy, treat advanced stages of the disease, particularly the vasculopathy and have adverse side effects. Unavailability of effective treatments to prevent the incidence or progression of DR is a major clinical problem. There is a great need for therapeutic interventions capable of preventing retinal damage in DR patients. A growing body of evidence shows that neurodegeneration is an early event in DR pathogenesis. Therefore, studies of the underlying mechanisms that lead to neurodegeneration are essential for identifying new therapeutic targets in the early stages of DR. Deregulation of the polyamine metabolism is implicated in various neurodegenerative diseases, cancer, renal failure, and diabetes. Spermine Oxidase (SMOX) is a highly inducible enzyme, and its dysregulation can alter polyamine homeostasis. The oxidative products of polyamine metabolism are capable of inducing cell damage and death. The current review provides insight into the SMOX-regulated molecular mechanisms of cellular damage and dysfunction, and its potential as a therapeutic target for diabetic retinopathy. Structural and functional changes in the diabetic retina and the mechanisms leading to neuronal damage (excitotoxicity, loss of neurotrophic factors, oxidative stress, mitochondrial dysfunction etc.) are also summarized in this review. Furthermore, existing therapies and new approaches to neuroprotection are discussed.

Study of the Acute Effects of Povidone-Iodine on Conjunctival Bacterial Flora

PURPOSE

The purpose of this laboratory study was to assess the effect of povidone-iodine (PI) use topically on the conjunctiva in regard to needle bore contamination and to compare these results with our previous findings from an evaluation of bacterial contamination following gatifloxacin and moxifloxacin administration.

METHODS

We performed 100 conjunctival 27-gauge needle penetrations of both eyes of 13 fresh cadavers. Eyes were then soaked in 10% PI, after which conjunctiva was again penetrated 100 times. After conjunctival penetration, the needles were irrigated, and the irrigant was assessed for bacterial growth. Results were compared with previous work assessing fluoroquinolone effectiveness through the same model.

RESULTS

We observed a 28% (P = 0.003) decrease in bacterial growth and 40% (P < 0.0001) decrease in colony counts after PI placement. Differences between the effect of PI versus moxifloxacin and gatifloxacin were not statistically significant.

CONCLUSIONS

There is a greater decrease in bacterial load after treatment with PI for surface cultures than for cultures obtained through a needle bore passed through the conjunctiva. PI is a superior approach to topical antibiotics to decrease conjunctival bacterial load.

Profile of intraocular immune mediators in patients with age-related macular degeneration and the effect of intravitreal bevacizumab injection

PURPOSE

To measure intraocular cytokine levels in patients with exudative age-related macular degeneration and analyze changes in the cytokine profile 2 days after intravitreal bevacizumab injection.

METHODS

This prospective case-control study enrolled 37 patients (37 eyes) with age-related macular degeneration including polypoidal choroidal vasculopathy. Twenty-eight age-matched patients (28 eyes) who underwent cataract surgery were used as controls. Undiluted aqueous humor samples were collected after intravitreal bevacizumab injection. Two days after intravitreal bevacizumab injection, cataract surgery was performed and undiluted aqueous humor samples were collected at the beginning of surgery (10 eyes). Twenty-three cytokines were measured using flow cytometry. P values were corrected in multiple comparisons using the conservative Bonferroni-Holm method. The level of significance was set at 0.0022 (0.05/23).

RESULTS

At baseline, aqueous humor levels of vascular endothelial growth factor, angiogenin, interferon gamma-inducible protein (IP)-10, macrophage inflammatory protein (MIP)-1β, monokine induced by interferon γ (Mig), and monocyte chemotactic protein (MCP)-1 were significantly higher in the age-related macular degeneration group than in the control group (P < 0.0022). The result of exploratory multivariate analysis showed that elevated angiogenin level was an important factor that discriminates the two groups (P = 0.0004). Two days after intravitreal bevacizumab injection, vascular endothelial growth factor levels tended to be reduced (P = 0.049), whereas interleukin (IL)-6 and IL-8 levels increased significantly (P < 0.0022).

CONCLUSION

Vascular endothelial growth factor and also angiogenin, IP-10, MCP-1, MIP-1β, and Mig may be related to the pathogenesis of age-related macular degeneration. Intravitreal bevacizumab injection increases inflammatory cytokine levels, suggesting the induction of an inflammatory process.

Postinjection endophthalmitis in the comparison of age-related macular degeneration treatments trials (CATT)

OBJECTIVE

To describe the incidence and outcomes of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT) and to assess the effect of prophylactic topical antimicrobials on incidence.

DESIGN

Cohort study within a randomized clinical trial.

PARTICIPANTS

Patients enrolled in CATT.

METHODS

Patients with neovascular age-related macular degeneration received intravitreal injections of ranibizumab or bevacizumab under 1 of 3 dosing regimens. The study protocol specified preinjection preparation to include use of a sterile lid speculum and povidone iodine (5%). Use of preinjection and postinjection antibiotics was at the discretion of the treating ophthalmologist. Patients were followed up monthly for 2 years.

MAIN OUTCOME MEASURES

Development of endophthalmitis and visual acuity.

RESULTS

Endophthalmitis developed after 11 of 18 509 injections (1 per 1700 [0.06%]; 95% confidence interval, 0.03%-0.11%), and in 11 of 1185 patients (0.93%; 95% confidence interval, 0.52-1.66). Incidence of endophthalmitis was 0.15% among injections with no antibiotic use, 0.08% among injections with preinjection antibiotics only, 0.06% among injections with postinjection antibiotics only, and 0.04% among injections with preinjection and postinjection antibiotics (P = 0.20). All eyes were treated with intravitreal antibiotics and 4 underwent vitrectomy. Among the 11 affected eyes, the final study visual acuity was 20/40 or better in 4 eyes (36%), 20/50 to 20/80 in 2 eyes (18%), 20/100 to 20/160 in 3 eyes (27%), and worse than 20/800 in 2 eyes (18%). The final visual acuity was within 2 lines of the visual acuity before endophthalmitis in 5 eyes (45%).

CONCLUSIONS

Rates of endophthalmitis were low and similar to those in other large-scale studies. Use of topical antibiotics either before or after injection does not seem to reduce the risk for endophthalmitis.

Povidone-iodine contact time and lid speculum use during intravitreal injection

PURPOSE

To determine the time necessary for 5% povidone-iodine (PI) to cause a significant reduction in colony-forming units and whether a lid speculum increases the conjunctival flora.

METHODS

This was a prospective randomized study of 131 eyes undergoing intravitreal injection. Conjunctival samples were collected in a prospective protocol at three points before intravitreal injection: (1) no intervention (baseline), (2) after placement of a lid speculum, and (3) after treatment with 5% PI. Participants were randomized into three different PI exposure intervals. Cultures were incubated for 6 days, and the resulting colony-forming units were tallied for each intervention.

RESULTS

Use of 5% PI caused significant decrease in the number of colony-forming units (P < 0.0001). Exposure to PI for 15 seconds did not cause a significant reduction in conjunctival bacteria (P = 0.08), but a significant reduction was observed after 30 seconds of exposure and beyond (P = 0.0003). Placement of a lid speculum did not result in a significant increase or decrease in the number of colony-forming units when compared with baseline (P = 0.47).

CONCLUSION

The use of 5% PI causes a significant reduction in bacterial colonies, and 30 seconds of exposure appears to be an adequate time to decrease conjunctival bacterial counts. Lid speculum use before intravitreal injection does not affect the overall conjunctival flora.

Meta-analysis of endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents: causative organisms and possible prevention strategies

PURPOSE

To report the rates of endophthalmitis and the spectrum of causative organisms after intravitreal injection of anti-vascular endothelial growth factor agents and possible prevention strategies.

METHODS

Meta-analysis of the U.S. literature from 2005 to 2009 reporting endophthalmitis bacterial isolates after intravitreal injection of anti-vascular endothelial growth factor agents and comparison with reports of endophthalmitis bacterial isolates after intraocular surgery in the United States.

RESULT

Endophthalmitis after intravitreal injection occurred in 52 of 105,536 injections (0.049%) (95% confidence interval [CI], 0.038-0.065%). Among 50 cases of endophthalmitis with bacterial culture isolates, 24 (48.0% [95% CI, 34.8-61.5%]) were culture negative and 26 (52% [95% CI, 38.5-65.2%]) were culture positive. Among the 26 culture-positive isolates, causative organisms were coagulase-negative Staphylococcus in 17 cases (65.4% [95% CI, 46.0-80.6%]), Streptococcus species in 8 cases (30.8% [95% CI, 16.5-50.2%]), and Bacillus cereus in 1 case (3.8% [95% CI, 0.9-19.0%]). Streptococcus species were significantly more frequent after intravitreal injection than after intraocular surgery in the Endophthalmitis Vitrectomy Study (29 of 226 isolates, 9.0% [95% CI, 6.3-12.6%], P = 0.005), a report on clear corneal cataract surgery endophthalmitis (6 of 73 isolates, 8.2% [95% CI, 3.9-16.8%], P = 0.022), and a report on postvitrectomy endophthalmitis with no cases of Streptococcus species.

CONCLUSION

Streptococcal isolates are approximately three times more frequent after intravitreal anti-vascular endothelial growth factor injection than after intraocular surgery. Strategies to consider minimizing oropharyngeal droplet transmission may include avoiding talking, coughing, and sneezing or wearing surgical masks.

Incidence and management of acute endophthalmitis after intravitreal bevacizumab (Avastin) injection

INTRODUCTION

The aim of this study was to report the incidence and management of acute endophthalmitis after intravitreal injection of Avastin (bevacizumab), and visual acuity outcomes of three eyes of three patients who developed acute endophthalmitis following intravitreal injection of Avastin.

METHODS

This clinical retrospective, non-comparative study included 3022 intravitreal injections of 1.25 mg bevacizumab consecutively performed for 1822 eyes with exudative age-related macular degeneration and other retinal diseases. Of 3022 injections, 1200 were reinjections. After clinical appearance of post-injection endophthalmitis, immediate intervention was performed, including injection of intravitreal antibiotics and early pars plana vitrectomy.

RESULTS

Three eyes of three patients with acute postoperative endophthalmitis were identified in the first week following intravitreal injections of 1.25 mg bevacizumab. Among of these patients, two cases were culture-positive and one case was culture-negative. Compared with presenting visual acuities, all of three patients improved at the end of follow-up time. The overall incidence rate of post-injection culture-proven endophthalmitis was 0.066%.

DISCUSSION

Acute culture-proven endophthalmitis is still a potential complication of intravitreal bevacizumab injection (approximately 0.066%) despite using maximal sterile techniques. Acute post-injection endophthalmitis following intravitreal bevacizumab occurs rapidly and can result in severe loss of vision. Prompt recognition and treatment are key in maximizing outcomes in patients who developed endophthalmitis after intravitreal injection of bevacizumab.

Severe corneal changes following intravitreal injection of bevacizumab

PURPOSE

To report a series of severe corneal changes following intravitreal injection of bevacizumab (Avastin) for age-related macular degeneration.

DESIGN

Retrospective noncomparative case series.

METHODS

The authors retrospectively reviewed the corneal changes that developed after the procedure in 1200 (460 patients) intravitreal injections of bevacizumab.

RESULTS

Five significant corneal changes (1.1%) occurred in these patients within the 1st postinjection week. The severe corneal changes included corneal infiltrative keratitis (n = 2) and corneal stromal edema and descemet folds (n = 3). The findings depended on clinical examination and biomicroscopic and confocal evaluation. In terms of causality assessment, no rechallenge was possible. The appropriate treatment was applied and recovery was achieved in all patients during the follow-up period.

CONCLUSIONS

Intravitreal injection of bevacizumab may cause corneal changes. The safety and effects of bevacizumab on the cornea should be evaluated in detail.

Low-fluence-rate photodynamic therapy to treat subfoveal choroidal neovascularization in pathological myopia. A study of efficacy and safety

BACKGROUND

To evaluate the efficacy and safety of low-fluence-rate photodynamic therapy (LFPDT) to treat choroidal neovascularisation (CNV) secondary to pathological myopia (PM).

METHODS

Twenty-five eyes with CNV in PM underwent LFPDT, with a standard dose of verteporfin and timing but adopting fluence and irradiance rates reduced to 25 mJ/cm2 and 300 mW/cm2, respectively. Best corrected visual acuity (BCVA) was measured and biomicroscopy and fluorescein angiography (FA) were evaluated. Particular attention was paid to choroidal hypoperfusion, and to changes (depigmentation/atrophy) at the RPE level in areas exposed to laser light.

RESULTS

After a mean follow-up of 13.4+/-2.46 months (range: 12-21), and 1.37+/-0.66 treatments (range: 1-3), BCVA was stable in 29 (91%) eyes. Two (6%) patients gained more than three lines and one (3%) eye lost more than three lines. Mean greatest linear dimension did not change significantly (p=0.08) at the end of follow-up. RPE depigmentation was present in six eyes (18%) and no patient showed RPE atrophy.

CONCLUSIONS

LFPDT is effective and safe for CNV secondary to PM treatment, stabilizing visual acuity and lesion size and determining only mild RPE changes. Further controlled studies are needed to demonstrate the long-term efficacy and safety of this treatment option.

Endophthalmitis after intravitreal injections

Endophthalmitis following intravitreal injection is an infrequent but serious clinical problem. Infectious endophthalmitis must be differentiated from noninfectious inflammation. Depending on the series, the risk of endophthalmitis is very low. The use of a standardized injection protocol can reduce the risk of infection.

Off-label use of bevacizumab for the treatment of age-related macular degeneration: what is the evidence?

There is an active and controversial debate about the role of intravitreal bevacizumab versus approved drugs in the treatment of neovascular age-related macular degeneration (AMD). Because bevacizumab was available prior to the launch of ranibizumab, off-label use of the former became widespread and the cancer drug bevacizumab is the most commonly used medication in ophthalmology nowadays. This review considers every publication identified in MEDLINE using the keywords 'bevacizumab' and 'Avastin' between 1 June 2005 and 31 July 2008. The search identified 511 papers that were evaluated. In 33 studies, there was consistent and clear evidence for the efficacy of bevacizumab in neovascular AMD. However, the highest grade studies (three prospective, randomized, controlled trials) did not attain better than grade 2b level of evidence, and objective evaluation of the benefit of bevacizumab relative to representative controls was therefore not possible. Certainly, the available evidence is inferior to that obtained from the approval studies of ranibizumab and this should influence treatment selection and guidance of patients. These considerations indicate that important quality criteria need to be included in future studies to ensure more meaningful conclusions can be drawn. These include clearly defined inclusion criteria, information about the recruitment procedure (including data on withdrawals, excluded patients, concealed treatment allocation, use of intention-to-treat analyses and blinded assessment procedures). Although preclinical studies have almost exclusively found bevacizumab to be safe, the design utilized in clinical case series cannot rule out a possible increase in adverse events, which already show a high spontaneous incidence in elderly AMD patients. The superior evidence level for ranibizumab and the limited safety data for bevacizumab must be taken into consideration when evaluating the costs that a healthcare system is willing to spend. However, the superior grade of evidence for ranibizumab should not be confused with the (still missing) evidence for superior efficacy. The results of ongoing randomized, controlled, comparative trials will provide further data on the efficacy and cost effectiveness of bevacizumab and ranibizumab in the treatment of AMD. In the meantime, patients should be informed about the alternatives, the price differences and the restricted liability issue when off-label use of bevacizumab is offered.

Anti-vascular endothelial growth factor pharmacotherapy for age-related macular degeneration: a report by the American Academy of Ophthalmology

OBJECTIVE

To examine the evidence about the safety and efficacy of anti-vascular endothelial growth factor (VEGF) pharmacotherapies for the treatment of neovascular age-related macular degeneration (AMD).

DESIGN

Literature searches were conducted in May and October 2007 in PubMed with no date restrictions, limited to articles published in English, and in the Cochrane Central Register of Controlled Trials without a language limitation and yielded 310 citations. The first author reviewed the abstracts of these articles and selected 73 articles of possible clinical relevance for review by the panel. The panel deemed 64 of these articles sufficiently clinically relevant to review in full text and assigned ratings of level of evidence to each of the selected articles with the guidance of the panel methodologists.

RESULTS

Eleven studies provided level I evidence for intravitreal pegaptanib and ranibizumab for neovascular AMD; there were no studies rated level I for bevacizumab for neovascular AMD. Five studies were rated as level II, which included studies of ranibizumab and bevacizumab, and the remaining 38 articles retrieved were rated as level III. The studies do not provide information about long-term results or the value (comparative effectiveness) and cost-effectiveness of combined therapies.

CONCLUSIONS

Review of the available literature to date suggests that anti-VEGF pharmacotherapy, delivered by intravitreal injection, is a safe and effective treatment for neovascular AMD for up to 2 years. There is level I evidence to support this conclusion for pegaptanib and ranibizumab, but none for bevacizumab at this time.

Acute intraocular inflammation after intravitreous injections of bevacizumab for treatment of neovascular age-related macular degeneration

PURPOSE

Bevacizumab is an inhibitor of vascular endothelial growth factor widely used as an "off-label" treatment of neovascular age-related macular degeneration (AMD), despite the lack of clinical trial data on efficacy or safety of this drug. We describe acute intraocular inflammation after intravitreous injection of bevacizumab for the treatment of neovascular AMD.

DESIGN

A retrospective case series.

PARTICIPANTS

Patients with neovascular AMD treated with intravitreous injection of bevacizumab from clinical practices in 2 states (Victoria and South Australia) in Australia.

METHODS

We retrospectively reviewed cases of acute intraocular inflammation after intravitreous injection of bevacizumab for the treatment of neovascular AMD.

MAIN OUTCOME MEASURES

The detection and description of inflammation in a large cohort of patients.

RESULTS

There were 14 cases (11 women and 3 men), from a total of 1278 injections given. The mean age of patients was 83.7 years (range, 74-98). The majority had a prior injection of bevacizumab, with a mean number of injections of 2.7 (range, 1-6). Most patients presented within 24 hours of intravitreous injection, with rapid reduction in vision, but minimal discomfort. There were associated signs of ocular inflammation in the anterior and posterior segments of the eye. Visual acuity at presentation was substantially reduced compared with the preinjection acuity, although the vision rapidly improved with treatment over a period of 7-25 days toward preinjection visual acuity.

CONCLUSIONS

Intravitreous injection of bevacizumab for the treatment of neovascular AMD may be associated with acute intraocular inflammation. Differentiation from infectious endophthalmitis is important for appropriate management of this condition.

Incidence of acute onset endophthalmitis following intravitreal bevacizumab (Avastin) injection

PURPOSE

To report the incidence of acute endophthalmitis as a complication of intravitreal bevacizumab (Avastin) (IVB) injection in a tertiary vitreoretinal group practice.

METHODS

A retrospective chart review of 5,233 consecutive eyes that underwent IVB injection at Retina Consultants of Alabama (RCA) from October 1, 2005, to August 31, 2007, was performed to identify cases of acute endophthalmitis.

RESULTS

During the 23-month study interval, the overall incidence rate of postinjection endophthalmitis was 0.019% (1/5,233). In the single case of acute endophthalmitis, bacterial cultures revealed coagulase-negative Staphylococcus (CNS) species. Visual acuity after treatment for endophthalmitis was improved (baseline 4/400) to 20/400 at two months after the initial IVB injection.

CONCLUSIONS

Acute endophthalmitis is a rare potential complication of IVB. Prophylaxis with topical povidone-iodine and adherence to aseptic technique minimizes the risk of postinjection infection.

SUMMARY STATEMENT

A retrospective review of 5,233 consecutive intravitreal injections of bevacizumab (Avastin) revealed only a single case of acute endophthalmitis. Adherence to aseptic technique and the use of povidone-iodine prophylaxis minimizes the risk of postinjection intraocular infection.

[Intravitreal injection. Monitoring to avoid postoperative complications]

Intravitreal injection is generally regarded as safe. Many of the potential complications caused by this procedure are extremely rare and can be avoided by careful inspection beforehand and proper performance of the injection. In rare cases, however, the administered drugs may cause various pharmacological side effects. This article summarizes the safety profiles of Macugen and Lucentis from the drug approval studies and describes initial findings on possible or observed side effects after intravitreal administration of Avastin. In addition, important points to observe in order to avoid intra- and postoperative complications are provided.

Comparative therapy evaluation of intravitreal bevacizumab and triamcinolone acetonide on persistent diffuse diabetic macular edema

PURPOSE

To compare the effect of an intravitreal injection of bevacizumab, an anti-vascular endothelial growth factor (VEGF) antibody, with that of triamcinolone acetonide, a corticosteroid for reduction of diabetic macular edema (DME).

DESIGN

Prospective, comparative interventional case series.

METHODS

Twenty-eight eyes of 14 patients with bilateral DME participated in this study. In each patient, one eye received an intravitreal injection of 4 mg triamcinolone acetonide and the other eye received 1.25 mg bevacizumab. The clinical course of best-corrected visual acuity (VA) with a logarithm of the minimum angle of resolution chart and averaged foveal thickness using optical coherence tomography was monitored for up to 24 weeks after the injection.

RESULTS

Before the injection, foveal thickness and VA were 522.3 +/- 91.3 microm and 0.64 +/- 0.28 microm in the triamcinolone-injected eye, and 527.6 +/- 78.8 microm and 0.61 +/- 0.18 microm in the bevacizumab-injected eye, respectively; there was no significant difference between the eyes. One week after the injection, both eyes showed significant regression of macular edema. The triamcinolone-injected eye (342.6 +/- 85.5 microm and 0.33 +/- 0.21 microm) showed significantly better results than the bevacizumab-injected eye (397.6 +/- 103.0 microm and 0.37 +/- 0.17 microm). However, both eyes showed the recurrence of macular edema with time, even at 24 weeks. Triamcinolone (410.4 +/- 82.4 microm and 0.47 +/- 0.25 microm) kept better results than bevacizumab (501.6 +/- 92.5 microm and 0.61 +/- 0.17 microm).

CONCLUSIONS

With the generally used concentration, intravitreal injection of triamcinolone acetonide showed better results in reducing DME and in the improvement of VA than that of bevacizumab, suggesting that the pathogenesis of DME is not only attributable to VEGF-dependency, but is also attributable to other mechanisms suppressed by corticosteroid.

Bevacizumab: off-label use in ophthalmology

Bevacizumab is a full-length, humanized monoclonal antibody directed against all the biologically active isoforms of vascular endothelial growth factor (VEGF-A). The antibody was initially designed and studied as an anti-angiogenic strategy to treat a variety of solid tumors. After approval by the US Food and Drug Administration, bevacizumab gained access into ophthalmology to treat various types of neovascular diseases. Since the first report in 2005 more than 100 publications share the experience with bevacizumab in ophthalmology. Two authors independently assessed the research results from Pubmed to April 2007. The reference list is a selection of key publications related to the issue. Currently, there is no well-designed randomized controlled trial yet to establish the efficacy and safety of intraocular bevacizumab for any ocular disease in spite of its assumed characteristics representing the most cost-effective VEGF inhibitor.