Bevacizumab wirkt nicht toxisch auf Zellen des menschlichen Auge

Intraocular Pressure Changes after Intravitreal Bevacizumab or Ranibizumab Injection: A Retrospective Study

Purpose

To determine intraocular pressure (IOP) changes after intravitreal bevacizumab or ranibizumab injection administered for various retinal disorders.

Methods

A retrospective chart review of 796 eyes of 574 patients receiving intravitreal ranibizumab (0.5 mg) and/or bevacizumab (1.25 mg) injection for different retinal diseases from March 2009 to December 2016 was performed. Ocular hypertension (OHT) was defined as IOP >21 mmHg or an increase in IOP of >5 mmHg from the baseline. IOP at the baseline and at various time periods after the injection was evaluated in the injected eyes and fellow control eyes.

Results

One hundred and thirty-one eyes received either a single dose of bevacizumab or ranibizumab intravitreal injection unilaterally, 222 patients received single injection in both the eyes (n = 444 eyes), and 221 eyes received multiple doses of the injection. OHT was noted in 11 eyes (1.38%), of which 3 eyes (0.38%) had transient OHT and 8 eyes (1%) had delayed and sustained OHT and among them, 3 eyes (0.4%) progressed to glaucoma. Preinjection IOP was significantly higher in the treated eyes when compared to the control untreated eyes (P = 0.006).

Conclusions

Incidence of delayed and sustained OHT is low after a single or multiple intravitreal bevacizumab and ranibizumab injections. Clinicians should be aware of possibility of OHT or glaucoma after the procedure.

Anti-VEGF Treatment in Corneal Diseases

BACKGROUND

Corneal neovascularization (CN) is a clue feature of different ocular pathological conditions and can lead to corneal edema and opacification with subsequent vision loss. Vascular endothelial growth factor (VEGF), which plays a key role in new vessels formation, proliferation and migration, was found to be up-regulated in these conditions. Nowadays, it is possible to downregulate the angiogenic process by using anti-VEGF agents administered by different routes.

OBJECTIVE

To evaluate the efficacy, safety and possible future directions of anti-VEGF agents used for the treatment of CNV owing to different aetiologies.

METHODS

A computerized search of articles dealing with the topic of anti-VEGF therapy in CN was conducted in PubMed, Scopus and Medline electronic databases. The following key phrases were used: anti-VEGF agents, corneal neovascularization, bevacizumab, ranibizumab, vascular endothelial growth factor, angiogenesis.

RESULTS

The use of anti-VEGF therapy in the treatment of CN reduced pathological vessel density without causing significant side effects. Various administration routes such as topical, subconjunctival and intrastromal ones are available, and the choice depends on patient and disease characteristics. Much more effectiveness is achieved in case of early administration before mature and wellestablished vessels take place. A combined approach between various drugs including anti-VEGF agents should be adopted in those cases at higher risk of neovascularization recurrence such as chronic long-standing diseases where ischemic and inflammatory stimuli are not definitively reversed.

CONCLUSION

The efficacy and safety of anti-VEGF agents support their adoption into the daily clinical practice for the management of CN.

The acute and chronic effects of intravitreal anti-vascular endothelial growth factor injections on intraocular pressure: A review

The acute and chronic effects of repeated intravitreal antivascular endothelial growth factor (VEGF) injections on intraocular pressure have not been fully characterized, and the development of sustained ocular hypertension could adversely affect patients who are at risk of glaucomatous optic neuropathy. As expected, volume-driven, acute ocular hypertension immediately follows intravitreal injection, but this pressure elevation is generally transient and well tolerated. Several medications have been investigated to limit acute ocular hypertension following anti-VEGF therapy, but the benefits of pretreatment are not conclusive. Chronic, sustained ocular hypertension, distinct from the short-term acute ocular hypertension after each injection, has also been associated with repeated intravitreal anti-VEGF injections. Risk factors for chronic ocular hypertension include the total number of injections, a greater frequency of injection, and preexisting glaucoma. Proposed mechanisms for chronic ocular hypertension include microparticle obstruction, toxic or inflammatory effects on trabecular meshwork, as well as alterations in outflow facility by anti-VEGF agents. Although limiting anti-VEGF therapy could minimize the risk of both acute and chronic ocular hypertension, foregoing anti-VEGF therapy risks progression of various macular diseases with resulting permanent central vision loss. While definitive evidence of damage to the retinal nerve fiber layer is lacking, patients receiving repeated injections should be monitored for ocular hypertension and patients in whom sustained ocular hypertension subsequently developed should be periodically monitored for glaucomatous changes with optic nerve optical coherence tomography and static visual fields.

[Analysis of cardiovascular diseases after the upload phase with intravitreal ranibizumab and bevacizumab in patients with exudative age-related macular degeneration]

BACKGROUND

The intravitreal administration of vascular endothelial growth factor (VEGF) inhibitors is the gold standard in the treatment of exudative age-related macular degeneration (AMD) but the possible risks of systemic, particularly cardiovascular side effects are still discussed.

PATIENTS AND METHODS

We prospectively followed 111 patients at the University Hospital in Göttingen with exudative AMD and intravitreal ocular treatment with bevacizumab and ranibizumab during the upload phase of 3 months using a questionnaire for documentation of possible cardiovascular events.

RESULTS

In 5 out of 111 patients angina pectoris was observed and in 6 patients the antihypertensive medication had to be increased. No differences were found between bevacizumab and ranibizumab. A patient with pre-existing cardiovascular diseases suffered a stroke in the upload phase but no thromboembolic events were observed in the other patients.

CONCLUSION

In this small but prospective clinical study no increased risk for cardiovascular events during the upload phase of the VEGF inhibitors ranibizumab and bevacizumab could be detected when taking the age and pre-existing cardiovascular diseases into consideration.

Effects of commonly used intravitreal anti-vascular endothelial growth factor drugs on mesenchymal stem cells derived from the limbus and ciliary body

BACKGROUND

To investigate the effects of commonly used intravitreal anti-vascular endothelial growth factor (anti-VEGF) antibodies on proliferation index and viability of mesenchymal stem cells derived from ciliary body and limbus (CB-MSC and LMSC).

METHODS

CB-MSCs and LMSCs were isolated from newborn rats' eyes, and they were expanded in medium by the explant method. Intravitreally used anti-VEGF drugs, aflibercept, bevacizumab and ranibizumab were tested into the 16-well plates, respectively, at four different concentrations. After keeping them for 48 h, the proliferation indexes and viabilities of CB-MSCs and LMSCs were compared separately by Real-Time Cell Analyzer and Methylthiazoltetrazoli (MTT) test.

RESULTS

Anti-VEGFs used at 5-times and 10-times of the standard clinical dosage caused statistically significant negative effects on proliferation indexes of CB-MSCs and LMSCs at the 24^th hour compared to control group. Only the anti-VEGF group that had 10-times dosage of those used clinically had a statistically significant negative effect on the viabilties of CB-MSCs and LMSCs.

CONCLUSION

Administrations of high doses or repeated standard doses of intravitreal anti-VEGF agents may affect the proliferation indexes and viabilities of CB-MSCs and LMSCs adversely. These novel findings deserve further in vivo investigations.

Ocular Hypertension Following Intravitreal Antivascular Endothelial Growth Factor Therapy: Review of the Literature and Possible Role of Nitric Oxide

PURPOSE

To review the literature regarding ocular hypertension following intravitreal antivascular endothelial growth factor therapy, and to propose a novel mechanism for the development of ocular hypertension as a result of such therapy.

METHODS

The PubMed database was used to identify publications by using combinations of the search terms, "glaucoma," "ocular hypertension," "pegaptanib," "bevacizumab," "ranibizumab," "aflibercept," "anti-vascular endothelial growth factor," intraocular pressure," and "intravitreal." The reference lists of these publications were also reviewed for relevant articles.

RESULTS

Numerous articles have been published describing ocular hypertension, either immediate-term/short-term or delayed/sustained, following intravitreal antivascular endothelial growth factor therapy. Ocular hypertension has been reported following intravitreal pegaptanib, bevacizumab, and ranibizumab, and aflibercept. On the basis of the fact that vascular endothelial growth factor, normally present as a vascular modulating and reparative growth factor, is known to upregulate endothelial nitric oxide (NO) synthase, and that NO has been shown to decrease intraocular pressure in both normal and glaucomatous human and animal eyes, we propose a novel mechanism for sustained ocular hypertension following intravitreal antivascular endothelial growth factor therapy. We propose that such intravitreal therapy may lead to decreased NO in the anterior segment, which then leads to trabecular meshwork constriction, decreased outflow facility, and increased intraocular pressure.

CONCLUSIONS

Sustained ocular hypertension following the intravitreal administration of antivascular endothelial growth factor agents is a potentially serious side effect that has not been adequately explained. Further investigation is necessary to determine the role of NO in the mediation of this adverse effect.

Intraocular Pressure Changes in Non-Glaucomatous Patients Receiving Intravitreal Anti-Vascular Endothelial Growth Factor Agents

Purpose

To study the prevalence of sustained intraocular pressure (IOP) elevation associated with intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) agents.

Methods

Prospective comparative study. Non-glaucomatous patients scheduled to receive intravitreal injection of anti-VEGF therapy were recruited from an outpatient eye clinic, Songklanagarind Hospital between April 2013 and March 2014. The IOP was measured by Goldmann applanation tonometer before and at 1 hour, 1 week, 1 month, 3 months, and 6 months after injection. The IOP was compared using the repeated measures analysis. Sustained IOP elevation was defined as either an IOP > 21 mmHg or an increase from baseline ≥ 5 mmHg on two consecutive visits.

Results

Seventy eyes of 54 patients met the inclusion criteria. The most common diagnosis was diabetic macular edema (48%). The mean IOP ± standard deviation (SD) before treatment was 13.7 ± 2.8 mmHg. The means ± SDs after treatment at 1 hour, 1 week, 1 month, 3 months, and 6 months were 11.3 ± 2.6, 13.7 ± 3.6, 14.1 ± 3.3, 14.0 ± 2.3, and 13.7 ± 2.4 mmHg, respectively. A mean of IOP difference at 1 hour postinjection and at baseline was −2.36 ± 2.5 mmHg (P < 0.001). Four of 70 treated eyes (5.7%) developed sustained IOP elevation (IOP ≥ 5 mmHg from baseline on two consecutive visits). The IOP returned to baseline levels after 1 month, in three eyes. One eye had sustained IOP elevation at 3 and 6 months follow-up. Thereafter, IOP returned to baseline level. There was no need of anti-glaucoma medication.

Conclusions

After receiving intravitreal injection of anti-VEGF agent, a small proportion of non-glaucomatous eyes developed a sustained IOP elevation without requiring IOP-lowering treatment. At 1 hour postinjection, there was a significant reduction of the mean IOP compared with the baseline level.

Evaluating the safety of intracameral bevacizumab application using oxidative stress and apoptotic parameters in corneal tissue

AIM

To investigate the possible effects of intracameral bevacizumab on oxidative stress parameters and apoptosis in corneal tissue.

METHODS

In total, 30 rats were assigned randomly into the following three groups of 10 rats each: a sham group (Group 1; n=10), a control group [Group 2; balanced salt solution (BSS) was administered at 0.01 mL; n=10], and a treatment group (Group 3; bevacizumab was administered at 0.25 mg/0.01 mL; n=10). The total antioxidant status (TAS) and the total oxidant status (TOS) in the corneal tissue and blood samples were measured, and the oxidative stress index (OSI) was calculated. Additionally, corneal tissue histopathology was evaluated for caspase-3 and -8 staining and apoptotic activity.

RESULTS

In the blood samples, the TAS, TOS, and OSI levels were not significantly different (all P>0.05). Compared with the sham and control groups, the TOS and OSI levels in the corneal tissues were significantly different in the bevacizumab group (all P<0.05). No statistically significant differences were observed between the sham and control groups (all P>0.05). However, compared with the sham and control groups, greater immunohistochemical staining for caspases-3 and -8 and an elevated level of apoptotic activity were observed in the bevacizumab group.

CONCLUSION

This study revealed that intracameral bevacizumab injections seemed to be systemically safe but may have elicited local toxic effects in the corneal tissue, as indicated by the oxidative stress parameters and histopathological evaluations.

Complications of intravitreal injections in patients with diabetes

Intravitreal injections for the treatment of retinal disorders and intraocular infection have become a common ophthalmic procedure, and injections of anti-vascular endothelial growth factor agents or steroids are frequently performed for the treatment of diabetic macular edema or other diabetic vascular pathology. Diabetic patients may be at higher risk of adverse events than non-diabetic individuals given frequent systemic co-morbidities, such as cardiovascular and renal disease, susceptibility to infection, and unique ocular pathology that includes fibrovascular proliferation. Fortunately, many associated complications, including endophthalmitis, are related to the injection procedure and can therefore be circumvented by careful attention to injection techniques. This review highlights the safety profile of intravitreal injections in patients with diabetes. Although diabetic patients may theoretically be at higher risk than non-diabetic patients for complications, a comprehensive review of the literature does not demonstrate substantial increased risk of intravitreal injections in patients with diabetes.

Evaluation of intracameral injection of ranibizumab and bevacizumab on the corneal endothelium by scanning electron microscopy

PURPOSE

To evaluate the effects of intracameral injection of ranibizumab and bevacizumab on the corneal endothelium by scanning electron microscopy (SEM).

METHODS

Twenty-eight female rabbits were randomly divided into four equal groups. Rabbits in groups 1 and 2 underwent intracameral injection of 1 mg/0.1 mL and 0.5 mg/0.05 mL ranibizumab, respectively; group 3 was injected with 1.25 mg/0.05 mL bevacizumab. All three groups were injected with a balanced salt solution (BSS) into the anterior chamber of the left (fellow) eye. None of the rabbits in group 4 underwent an injection. Corneal thickness and intraocular pressure were measured before the injections, on the first day, and in the first month after injection. The rabbits were sacrificed and corneal tissues were excised in the first month after injection. Specular microscopy was used for the corneal endothelial cell count. Endothelial cell density was assessed and comparisons drawn between the groups and the control. Micrographs were recorded for SEM examination. The structure of the corneal endothelial cells, the junctional area of the cell membrane, the distribution of microvillus, and the cell morphology of the eyes that underwent intracameral injection of vascular endothelial growth factor (VEGF), BSS, and the control group were compared.

RESULTS

Corneal thickness and intraocular pressure were not significantly different between the groups that underwent anti-VEGF or BSS injection and the control group on the first day and in the first month of injection. The corneal endothelial cell count was significantly diminished in all three groups; predominantly in group 1 and 2 (P<0.05). The SEM examination revealed normal corneal endothelial histology in group 3 and the control group. Eyes in group 1 exhibited indistinctness of corneal endothelial cell borders, microvillus loss in the luminal surface, excessive blebbing, and disintegration of intercellular junctions. In group 2, the cell structure of the corneal endothelium and intercellular junctions were normal. However, a relative reduction was observed in the microvillus density of endothelial cells. Although eyes in group 3 were morphologically similar to fellow eyes and the control group, disarrangement in endothelial cell borders was evident.

CONCLUSION

The SEM examination pointed out deterioration in endothelial cell morphology after intracameral injection of 1 and 0.5 mg ranizumab. However, the effects of intracameral bevacizumab injection on corneal endothelial cells were similar to those found in fellow eyes and the control group. Further large-scale studies that examine the cellular changes by transmission electron microscopy are required to support the results of the present study that evaluates the structural changes in endothelial cells by SEM.

The link between intravitreal antivascular endothelial growth factor injections and glaucoma

PURPOSE OF REVIEW

To summarize the reports of both transient and sustained elevation in intraocular pressure (IOP) associated with intravitreal injections of antivascular endothelial growth factor (anti-VEGF) agents and to review the possible mechanisms for these findings.

RECENT FINDINGS

Transient elevation in IOP is common after intravitreal injection of anti-VEGF agents. Sustained IOP elevation is less commonly seen but can require medical and/or surgical intervention. The mechanism for sustained IOP elevation is not well understood but has been attributed to trabecular meshwork injury from repeated injections, a potential toxic or inflammatory reaction after exposure to the biologic agents and/or vehicle, or mechanical blockade of the trabecular meshwork by protein aggregates or contaminant particles associated with packaging and injection techniques, among other potential causes.

SUMMARY

Intravitreal anti-VEGF injections are commonly used to treat neovascular diseases of the eye. Although they have a favorable side-effect profile, their use can be associated with both transient and sustained elevation in IOP. Further research is necessary to determine the cause of these findings.

Local and systemic complications after intravitreal administration of anti-vascular endothelial growth factor agents in the treatment of different ocular diseases: a five-year retrospective study

PURPOSE

To observe the frequency of complications in patients undergoing intravitreal anti-VEGF injections for different ocular diseases in a five-year period.

MATERIALS AND METHODS

Charts of patients receiving intravitreal anti-VEGF were retrospectively reviewed. Out of 1173 eyes, 762 were treated with bevacizumab, 382 with ranibizumab, and 29 with pegaptanib. Data recorded included demographic information, clinical findings, total injections received, and info about the onset of adverse effects.

RESULTS

12.86% of the eyes treated with bevacizumab presented side-effects, while ratings in the ranibizumab and pegaptanib groups were 15.97% and 20.69%, respectively. Odds ratios calculated comparing incidences after each anti-VEGF are 0.78 (bevacizumab versus ranibizumab, p = 0.152), 0.57 (bevacizumab versus pegaptanib, p = 0.227), and 0.73 (ranibizumab versus pegaptanib, p = 0.508). A total of 185 complications were detected (62.16% after bevacizumab). Ocular side-effects registered were 40 cases of sustained intraocular pression (IOP) elevation, one infectious uveitis, one retinal detachment, and one sub-retinal hemorrhage. Other cases were related to transient IOP elevation immediately after injection. Systemic complications registered were one case of nausea, one episode of chest pain with acute vision loss, and one case of acute blood hypertension.

CONCLUSIONS

The majority of significant complications occurred in patients receiving multiple bevacizumab administrations. However, results may be affected by the difference in the utilization amount for each drug. AMD patients were the most represented, probably due to greater indication to treatment.

The effects of aflibercept on the viability and metabolism of ocular cells in vitro

PURPOSE

To investigate the effects of the vascular endothelial growth factor-neutralizing agent aflibercept on primary cultures of human trabecular meshwork cells (hTMC), human scleral fibroblasts (hFibro), and a retinal pigment epithelial cell line (ARPE-19).

METHODS

Various concentrations of aflibercept were incubated with confluent cell cultures for 24 hours. Ranibizumab was used as an active control for comparison. Assays of cellular metabolism (MTT assay) and cell viability (calcein dye uptake) were performed.

RESULTS

Compared with untreated controls (100% live), a 24-hour exposure to 1 mg/mL aflibercept had no significant effect on cell viability in hTMC (100.1 ± 1.7%), hFibro (102.4 ± 2.4%), or ARPE-19 (99.3 ± 3.9%) cells. Aflibercept vehicle controls also had no detrimental effect. Aflibercept (1 mg/mL) had no statistically significant effect on metabolic activity in hTMC (84.3 ± 10.2%), hFibro (102.7 ± 4.3%), and ARPE-19 (104.6 ± 12.6%) cells. When compared side-by-side in ARPE-19 cells, aflibercept and the anti-vascular endothelial growth factor agent ranibizumab had no toxicity at the highest concentration tested (1 mg/mL).

CONCLUSION

The authors' data reveal that concentrations of aflibercept in the range expected to occur in the human vitreous after intraocular injection are not harmful in an in vitro cell assay.

Clinical predictors of sustained intraocular pressure elevation due to intravitreal anti-vascular endothelial growth factor therapy

PURPOSE

We assess for frequency and predictive factors related to sustained intraocular pressure (IOP) elevation in eyes with neovascular age-related macular degeneration receiving intravitreal injections of ranibizumab and/or bevacizumab.

METHODS

A total of 328 patients with neovascular age-related macular degeneration (449 eyes) who presented to a single physician over a 6-month period were retrospectively assessed for baseline demographic/clinical information, total number of bevacizumab and/or ranibizumab injections, and sustained IOP elevation on 2 or more consecutive visits (absolute IOP >25 mmHg, increase above baseline >10 mmHg, or IOP of >21 mmHg and increase of >5 mmHg). Cox regression survival analysis and multivariate logistic regression were performed to assess the influence of intravitreal injections on experiencing sustained IOP elevation.

RESULTS

Overall, 32 eyes (7.1%) experienced sustained IOP elevation. Survival analysis showed a significant effect of the number of anti-vascular endothelial growth factor injections on sustained IOP elevation (hazard ratio, 1.085; 95% confidence interval: 1.06-1.11, P < 0.001). Also, there was an increased odds ratio (16.1, P = 0.008) of sustained IOP elevation in eyes receiving ≥29 injections compared with ≤12 injections. After controlling for the confounder (prior intravitreal steroid injection), total number of injections still showed a statistically significant association (P = 0.002).

CONCLUSION

A greater number of intravitreal anti-vascular endothelial growth factor injections is associated with an increased risk for sustained IOP elevation in eyes with neovascular age-related macular degeneration receiving intravitreal ranbizumab and/or bevacizumab.

Intraocular Pressure rise after Anti-VEGF Treatment: Prevalence, Possible Mechanisms and Correlations

Intraocular pressure (IOP) rise after anti-vascular endothelial growth factor (VEGF) treatment for neovascular age-related macular degeneration (AMD) can be either short-term or long-term and may require medical intervention. Short-term IOP spikes are a fairly common and well recognized complication of anti-VEGF injections. Long-term IOP rise is less well-understood and disputed as a complication by some authors. We try to review current literature on the subject and especially studies focused on the prevalence of this complication, speculate on possible mechanisms of IOP rise and discuss correlations of long-term IOP rise with the nature of the injected agent, average number of injections, previous glaucoma history and other factors. How to cite this article: Kampougeris G, Spyropoulos D, Mitropoulou A. Intraocular Pressure rise after Anti-VEGF Treatment: Prevalence, Possible Mechanisms and Correlations. J Current Glau Prac 2013;7(1):19-24.

A lack of delayed intraocular pressure elevation in patients treated with intravitreal injection of bevacizumab and ranibizumab

PURPOSE

The purpose of this study was to report the rate of intraocular pressure (IOP) elevation after intravitreal injections of anti-vascular endothelial growth factor agents for exudative age-related macular degeneration.

METHODS

Retrospective chart review of all patients receiving intravitreal ranibizumab and/or bevacizumab injections for exudative age-related macular degeneration from November 2005 to June 2010. Delayed ocular hypertension (OHT) was defined as either an IOP ≥22 mmHg on 2 consecutive visits (with an increase from baseline >6 mmHg) or an IOP >26 mmHg on a single visit with a concomitant initiation or augmentation of IOP-lowering treatment. Noninjected fellow eyes served as controls. Incidence of delayed OHT was analyzed using survival analyses, with risk assessed by Cox proportional hazards regression models. Eyes with glaucoma were evaluated separately.

RESULTS

Three hundred and two treated eyes and 226 control eyes met inclusion criteria. In eyes with exudative age-related macular degeneration without glaucoma, 3 of 270 injected eyes (0.51% incidence per eye-year) developed delayed OHT compared with 4 of 195 control eyes (1.00% incidence per eye-year), a difference that was not statistically significant (hazard ratio = 0.48; 95% confidence interval: 0.11-2.23). In eyes with exudative age-related macular degeneration and glaucoma, 2 of 32 injected eyes developed delayed OHT (3.1% incidence per eye-year) compared with 3 of 31 control eyes (5.7% incidence per eye-year), a difference that was not statistically significant (hazard ratio = 0.59; 95% confidence interval: 0.10-3.60).

CONCLUSION

The incidence of delayed OHT after intravitreal anti-vascular endothelial growth factor injections was low and did not differ between injected and control eyes, including eyes with glaucoma. These results argue against a significant risk of IOP elevation because of repeated anti-vascular endothelial growth factor therapy.

Safety of bevacizumab on extraocular muscle in a rabbit model

Purpose

The purpose of this study was to investigate the myotoxicity of bevacizumab on extraocular muscles in a rabbit model.

Methods

Thirty New Zealand white rabbits were used for this study. The animals were evenly divided into two groups. In the first group, 15 rabbits were treated with intramuscular injections of bevacizumab (1.25 mg/0.05 mL) in the right superior rectus muscle and normal saline solution (0.05 mL) in the left superior rectus muscle. In the second group, 15 rabbits were treated with subconjunctival injections of bevacizumab (2.5 mg/0.1 mL) in the right superior subconjunctival area and normal saline solution (0.1 mL) in the left superior subconjunctival area. Five rabbits in each group were sacrificed at one day, two weeks and four weeks after the injections. Extraocular muscle samples were prepared for light microscopic (LM) and electron microscopic (EM) examination. Degrees of acute inflammation were evaluated via CD-11b immunohistochemistry, and global muscle change was investigated using hematoxylin and eosin stains. Intensity of fibrosis was evaluated using Masson trichrome stains, and ultrastructural changes were observed on EM.

Results

We observed no significant inflammatory cell infiltration, muscle necrosis or fibrotic change in treated and control eyes. EM findings revealed no significant damage to muscle or vascular tissue after bevacizumab injection.

Conclusions

We found no signs of extraocular muscle toxicity after LM and EM intramuscular and subconjunctival bevacizumab injections in a rabbit model.

Anti-VEGF therapy with bevacizumab for anterior segment eye disease

PURPOSE

To review the current literature concerning the use of bevacizumab in treating neovascular disorders affecting the anterior segment ocular structures.

METHODS

The authors reviewed the literature on anti-vascular endothelial growth factor (VEGF) therapy with bevacizumab for various anterior segment neovascular disorders that was indexed in MEDLINE (up to January 2011).

RESULTS

Response to bevacizumab anti-VEGF therapy is variable, based on the amount of scarring, the chronicity and extent of corneal neovascularization, the disease process, and the medication formulation and its route of administration. Anti-VEGF agents are especially effective when administered early, before anatomical changes, such as corneal neovascularization and/or angle closure, are established. Neovascularization can recur if the ischemic or inflammatory process is not reversed, so eyes with long-standing diseases, such as autoimmune disorders that involve ongoing inflammation and VEGF production, seem to be less responsive to bevacizumab anti-VEGF therapy. For established neovascularization, combining anti-VEGF agents with the removal of established vessels may be more effective than anti-VEGF therapy alone. Subconjunctival bevacizumab may be more appropriate for focal, deep, and peripheral neovascularization, whereas diffuse superficial neovascularization with central corneal involvement may be best treated via topical application.

CONCLUSIONS

Besides the widely accepted use of bevacizumab in cancer therapy and chorioretinal neovascularization, the initial, striking, short-term response and patients' high tolerance of local bevacizumab therapy offer encouraging results for the potential role of anti-VEGF agents in treating anterior segment neovascular disorders. Controlled prospective trials are needed to establish the long-term safety, efficacy, and dosing guidelines for the use of anti-VEGF agents in anterior segment neovascularization.

Effect on intraocular pressure in patients receiving unilateral intravitreal anti-vascular endothelial growth factor injections

PURPOSE

We assessed the frequency and predictive factors related to intraocular pressure (IOP) elevation in neovascular age-related macular degeneration (AMD) patients undergoing unilateral intravitreal ranibizumab and/or bevacizumab injections.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Charts of 207 patients with neovascular AMD who presented to a single physician at a retinal referral practice over a 6-month period were retrospectively reviewed.

METHODS

Data recorded included demographic information, clinical findings, total number of bevacizumab and ranibizumab injections received and IOP at each visit. Increases above baseline IOP of >5, >10, or >15 mmHg on ≥2 consecutive visits while under treatment were noted.

MAIN OUTCOME MEASURES

The frequency of IOP elevation was compared between treated and untreated eyes. In addition, among treated eyes, frequency and odds ratio of experiencing IOP elevation >5 mmHg above baseline on ≥2 consecutive visits was stratified by number of injections. For the main regression analysis, the outcome variable was IOP elevation >5 mmHg on ≥2 consecutive visits and the main independent variable was total number of injections.

RESULTS

On ≥2 consecutive visits, 11.6% of treated versus 5.3% of untreated/control eyes experienced IOP elevation of >5 mmHg. The mean number of injections was higher in those with (24.4; 95% confidence interval [CI], 20.9-28.0; range, 9-39) than without IOP elevation of >5 mmHg (20.4; 95% CI, 18.9-21.8; range, 3-48) on ≥2 consecutive visits. There was an increased odds ratio (5.75; 95% CI, 1.19-27.8; P = 0.03) of experiencing IOP elevation >5 mmHg on ≥2 consecutive visits in patients receiving ≥29 injections compared with ≤12 injections. Of the factors considered, only the total number of injections showed a statistically significant association with IOP elevation >5 mmHg above baseline on ≥2 consecutive visits in treated eyes (P = 0.05).

CONCLUSIONS

A greater number of intravitreal anti-vasular endothelial growth factor injections is associated with an increased risk for IOP elevation >5 mmHg on ≥2 consecutive visits in eyes with neovascular AMD receiving intravitreal ranbizumab and/or bevacizumab.

Effect on anterior chamber bevacizumab injection combined with seton implantation in treatment of rubeosis iridis in neovascular glaucoma

OBJECTIVE

To evaluate the effect of anti-VEGF (bevacizumab) injection to the posterior chamber (BIPC) behind the iris combined with seton implantation in treatment of neovascular glaucoma (NVG).

METHODS

Twenty-eight eyes with NVG who underwent BIPC, prospectively evaluated. Anterior segment photographs were taken for grading of neovascularization on anterior segment in pretreatment period and at each follow-up. Grading and regression of rubeosis iridis was classified according to Teich and Walsh grading system and glaucoma filtration surgery with drainage device was performed following BIPC.

RESULTS

The mean pre-BIPC IOP was 39.71 ± 7.09 mmHg, post-BIPC IOP in the 1st, 2nd day, 1st week, 1st, 3rd, 6th month were 19.7 ± 8.9 mmHg, 13.5 ± 6.7 mmHg, 9.9 ± 3.4 mmHg, 13.07 ± 5.3 mmHg, 16.6 ± 5.03 mmHg, 18.5 ± 3.8 mmHg, respectively. Twenty seven eyes underwent seton implantation surgery. No one had anterior segment bleeding during surgery. The pre-BIPC grades were Grade 4: 67.58%, Grade 3: 28.57%, Grade 2: 3.57%, no one had Grade 1or Grade 0, while post BIPC grade were at the 1st week Grade 1: 64.28%, Grade 0: 35.71%, no one had Grade 2 or more, at 1st month Grade 2: 3.57%, Grade 1: 39.28%, Grade 0: 57.14%, at 3rd month Grade 2: 17.85% Grade 1: 28.57%, Grade 0: 53.57%, no one had Grade 3 or more both in first and the third month, at 6th month Grade 3: 7.14%, Grade 2: 28.57%, Grade 1: 42.85%, Grade 0: 21.42%. and no one had Grade 4.

CONCLUSION

Significant reduction of NV was observed during the first week. Minimal increasement was seen in third month, significant regression effect persisted for 6 months. BIPC inhibited the peroperative risk of anterior segment bleeding, increased the surgical comfort and prevented the failure of filtration procedure by inhibiting reproliferation.

[Intracameral moxifloxacin: a safe option for endophthalmitis prophylaxis? In vitro safety profile for intraocular application]

BACKGROUND

Moxifloxacin (Vigamox), a 4th-generation fluoroquinolone, covers most isolates causing endophthalmitis. It is safe and effective for systemic and topical use; however, only very limited data are available on prophylactic intracameral administration to prevent endophthalmitis. This study investigated the safety of Vigamox for intracameral application in a cell-culture model.

METHODS

The endothelial toxicity of moxifloxacin (Vigamox) was evaluated in cultured human corneas. Primary human retinal pigment epithelium cells (RPEs), trabecular meshwork cells (TMCs), lens epithelium cells (LECs), and corneal endothelial cells (CECs) were treated with concentrations of Vigamox. Toxic effects were evaluated after 24 h (MTT assay and live-dead assay). By treating TMC, CEC, and RPE cells either with oxidative stress or tumor necrosis factor-alpha (TNF-a), lipopolysaccharide (LPS), and interleukin-6 (IL-6), the effects of moxifloxacin on cellular viability under conditions of inflammation were investigated.

RESULTS

No corneal endothelial toxicity could be detected after 30 days of treatment with moxifloxacin 500 microg/ml. Primary RPEs, TMCs, LECs, and CECs showed adverse effects on proliferation and viability only at concentrations higher than 150 microg/ml moxifloxacin. After preincubation with TNF-a, LPS, and IL-6 for 24 h and subsequent treatment with moxifloxacin at concentrations of 10-150 microg/ml for 24 h, no significant decrease in proliferation or viability was observed. H2O2 exposure did not increase cellular toxicity

CONCLUSION

Vigamox did not show significant toxicity on primary RPEs, TMCs, LECs, CECs, or human corneal endothelium at concentrations up to 150 microg/ml. The MIC90 of moxifloxacin for pathogens commonly encountered in endophthalmitis is known to be in the range of 0.25-2.5 microg/ml. Therefore, intracameral use of Vigamox at concentrations up to 150 microg/ml may be safe and effective for preventing endophthalmitis after intraocular surgery.

Effect of intravitreal ranibizumab on corneal endothelium in age-related macular degeneration

PURPOSE

To determine the effect of intravitreal injection of ranibizumab on the corneal endothelium in patients with choroidal neovascularization in age-related macular degeneration.

METHODS

Observational prospective case series study. Fifty-two eyes of 52 consecutive patients (29 men, 23 women; age range, 61-80 years) were evaluated. All participants received monthly intravitreal injections of (0.05 mL, 0.5 mg) ranibizumab for 3 consecutive months; the follow-up period was 6 months. Central corneal specular microscopy was performed before injection and at 7 days and 6 months after the first intravitreal injection. The endothelial cell density, coefficient of variation of cell size, and percentage of hexagonal cells were analyzed, and the central corneal thickness was measured.

RESULTS

There were no significant differences in the endothelial cell densities, coefficient of variation of cell sizes, and percentage of hexagonal cells values before injection and at 7 days and 6 months after the first intravitreal ranibizumab injection (P = 0.987, P = 0.822, and P = 0.918, respectively). There was also no significant difference in central corneal thickness measurements before injection and at 7 days and 6 months after the first intravitreal ranibizumab injection (P = 0.325).

CONCLUSION

Repeated intravitreal injections of 0.5 mg of ranibizumab do not seem to cause substantial changes in the corneal endothelium at 6 months.

Persistent ocular hypertension following intravitreal bevacizumab and ranibizumab injections

PURPOSE

To study ocular hypertension (OHT) following intravitreal injections of bevacizumab and/or ranibizumab in patients with age-related macular degeneration (AMD).

METHODS

Retrospective case series. Patients with AMD who were treated at a tertiary referral center with intravitreal bevacizumab and/or ranibizumab injections from January 1, 2006 to December 31, 2008 were studied. The development of OHT following these injections was investigated.

RESULTS

Four out of 116 patients with AMD (3.45%) developed sustained elevated intraocular pressure (IOP) after multiple intravitreal injections of bevacizumab 1.5 mg/0.06 mL and/or ranibizumab 0.5 mg/0.05 mL. An analysis of 4 cases revealed: None of the patients had a previous diagnosis or family history of glaucoma/OHT. Two patients had both bevacizumab and ranibizumab injections. Two patients developed OHT after recent intravitreal ranibizumab and 2 patients after recent intravitreal bevacizumab injection. Two patients were pseudophakic with a history of YAG capsulotomy. The range of preinjection IOP was 8-15 mmHg (mean, 13 mmHg). The range of postinjection IOP was 28-36 mmHg (mean, 31.75 mmHg). The range of IOP increase was 17-21 mmHg (mean, 18.75 mmHg). Mean number of pan-anti-VEGF injections prior to OHT was 13.3 (range, 3-19). A disrupted posterior capsule might predispose patients to the development of OHT.

CONCLUSIONS

Persistent OHT may occur after intravitreal anti-VEGF injection in patients with no previous diagnosis of glaucoma or OHT. OHT may persist across several visits and patients may require IOP-lowering therapy. Sustained elevation in IOP usually occurs after multiple injections.

In vivo corneal endothelial safety of intracameral bevacizumab and effect in neovascular glaucoma combined with Ahmed valve implantation

PURPOSE

To evaluate the corneal toxicity of intracameral bevacizumab in rabbit eyes and also the effects of intracameral bevacizumab in neovascular glaucoma patients combined with Ahmed glaucoma valve implantation.

MATERIALS AND METHODS

Intracameral bevacizumab (1.25 mg/0.05 mL) was injected into 5 eyes of 5 New Zealand white rabbits. A balanced salt solution (0.05 mL) was injected intracamerally in another 5 rabbits as a control. The corneal thickness, endothelial cell counts, and intraocular pressure were measured before and at 1, 2, and 4 weeks after the intracameral injection of bevacizumab and a balanced salt solution. Scanning electron microscopic examinations were performed at 1 and 4 weeks after injection. In the clinical cases, 6 patients who received an intracameral injection of bevacizumab (1.25 mg) and Ahmed glaucoma valve implantation were enrolled. The visual acuity, intraocular pressure, and regression of iris rubeosis by iris fluorescein angiography were recorded before and at 1 week, 1 month, and 2 months after the intracameral bevacizumab injection and Ahmed glaucoma valve implantation.

RESULTS

No morphologic and functional changes in the corneal endothelial cells were observed in the rabbit eyes after the intracameral bevacizumab and balanced salt solution injections. Iris rubeosis regression was observed in all eyes within 1 week after the injection. The visual acuity remained stable or improved, and the intraocular pressure was controlled in all eyes throughout the follow-up period. There were no ocular and systemic complications associated with the combined procedure.

CONCLUSIONS

An intracameral injection of bevacizumab may be a safe alternative treatment for iris rubeosis in neovascular glaucoma when combined with Ahmed glaucoma valve implantation.

Optimizing the deswelling process of organ-cultured corneas

PURPOSE

During deswelling of organ-cultured human corneas, endothelial cell loss occurs. Therefore, it is necessary to minimize the deswelling time and achieving an optimal central corneal thickness (CCT) of approximately 550 microm at the same time. We investigated the minimal deswelling time necessary and analyzed endothelial cell loss.

METHODS

Fifty-eight human corneas were stored between 13 and 81 days in organ culture. CCT was measured by optical coherence tomography. Measurements were performed before preparation, during culturing, before deswelling, and after varying deswelling periods (1-72 hours) using 5% dextran. Additionally, vital staining was performed in 6 human corneas to assess endothelial cell loss between 24 and 30 hours of deswelling. To evaluate absolute cell loss, endothelial cells were counted on human corneal pairs after 24 and 30 hours of deswelling.

RESULTS

After organ culture, mean CCT was 1194 microm. After 24 hours of deswelling in dextran-containing medium, mean CCT was 600 microm, whereas after 30 hours, mean CCT was 510 microm and hardly any corneas showed a CCT of more than 550 microm. Almost no further decrease in CCT was observed thereafter. No factors could be identified predicting the necessary deswelling time; however, paired corneas showed significant correlation of deswelling characteristics. We did not see any differences in endothelial cell loss 24 and 30 hours of deswelling or the ratio of living to dead endothelial cell counts.

CONCLUSIONS

Deswelling for 24 hours does not provide an optimal corneal thickness. Because endothelial cell loss does not increase between 24 and 30 hours of deswelling, a period of 30 hours is more suitable for obtaining sufficient corneal thickness.

The effect of different doses of intracameral bevacizumab on surgical outcomes of trabeculectomy for neovascular glaucoma

PURPOSE

To prospectively evaluate the effect of 1.25 mg and 2.5 mg intracameral bevacizumab on surgical outcomes of trabeculectomy for neovascular glaucoma (NVG), with primary outcome measures being the regression of neovascularization of iris (NVI) and reduction of intraocular pressure (IOP).

METHODS

Consecutive patients with neovascular glaucoma from December 2006 to March 2007 were randomized into two cohorts assigned to receive 1.25 mg (Group 1) or 2.5 mg (Group 2) intracameral bevacizumab prior to undergoing mitomycin C (MMC) trabeculectomy. Surgical outcome measures were evaluated following initial injection and during follow-up post-surgery.

RESULTS

The most common causes for iris neovascularization were central retinal vein occlusion (47.3%) and proliferative diabetic retinopathy (36.8%). Following intracameral bevacizumab, there was a reduction in IOP compared to baseline in both treatment groups (Group 1, n=9: -10.4+/-4.5 mmHg, p=0.57; Group 2, n=10: -12.1+/-5.5 mmHg, p=0.1). The reduction in IOP was not statistically significant between the two groups (p=0.55). None of the eyes underwent further retinal ablation post trabeculectomy. Reappearance of NVI was seen in three eyes (Group 1, n=2; Group 2, n=1) after 3 months. There was no statistically significant difference in regression of NVI grade between the treatment groups (p=0.1).

CONCLUSIONS

The efficacy of an intracameral dose of 2.5 mg of bevacizumab prior to trabeculectomy for eyes with NVG is not significantly different from a 1.25 mg dose. Intracameral bevacizumab followed by trabeculectomy results in good surgical outcomes. Longer follow-up would be needed to evaluate differences in recurrence rates of iris neovascularization using different dosages.

Effect of bevacizumab on human corneal endothelial cells: a six-month follow-up study

PURPOSE

To assess in vivo corneal endothelial changes occurring over a six-month period after the intravitreal injection of bevacizumab (Avastin; Genentech Inc, San Francisco, California, USA) in patients with various macular diseases.

DESIGN

Prospective case series.

METHODS

A total of 50 eyes from 50 consecutive patients received an intravitreal injection of 2.5 mg intravitreal bevacizumab. Specular microscopy, including central corneal thickness (CCT) and endothelial cell count, was performed on each patient for both eyes before injection and one day, seven days, three months, and six months after injection. The CCT at one and seven days was measured to evaluate the acute corneal endothelial damage; endothelial cell count at three and six months was used to estimate chronic corneal endothelial change.

RESULTS

All patients completed six months of follow-up. There was no significant difference in corneal thickness change between treated and nontreated eyes before injection or one and seven days after injection (P = .53, .34, and .87, respectively). There was also no difference in the treated eyes before injection and one and seven days after injection (P = .94). Long-term evaluation revealed that there was no significant difference in the corneal endothelial cell density of treated and nontreated eyes before injection and at three and six months after injection (P = .76, .13, and .22, respectively). There was also no difference in the treated eyes before injection and at three and six months after injection (P = .73).

CONCLUSIONS

The intravitreal injection of 2.5 mg bevacizumab seemed to have no harmful effects on the corneal endothelium.

[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.