Evaluation of cytotoxic effects of bevacizumab on human corneal cells

Comparison of photodynamic therapy with two different parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization

BACKGROUND

To the best of our knowledge, no studies have been performed to determine the optimal parameters of photodynamic therapy (PDT) combined with subconjunctival injection of bevacizumab for corneal neovascularization. This study aimed to compare the effect of photodynamic therapy with two different sets of parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization.

METHODS

Patients with stable corneal neovascularization (CNV) unresponsive to conventional treatment (topical steroid) were included in this study. Patients were divided into two groups, receiving PDT with two different sets of parameters (group 1 receiving fluence of 50 J/cm2 at 15 min after intravenous injection of verteporfin with, group 2 receiving fluence of 150 J/cm2 at 60 min after intravenous injection of verteporfin with). Subconjunctival injection of bevacizumab was performed immediately after PDT. All patients were followed for 6 months. Best-corrected visual acuity and intraocular pressure were evaluated, and slit-lamp biomicroscopy as well as digital photography were performed. Average diameter and cumulative length of corneal neovascular were measured to evaluate the corneal neovascularization.

RESULTS

Seventeen patients (20 eyes) were included in this study. At the last visit, the vision was improved in 12 eyes (60 %), steady in 4 eyes (20 %) and worsen in 4 eyes (20 %). The intraocular pressure (IOP) of all patients remained in normal range. A significant decrease in corneal neovascularization was showed in all the eyes after treatment. At 6 months after the combined treatment, the average diameter and cumulative length of vessels significantly decreased to 0.041 ± 0.023 mm (P < 0.05) and 18.78 ± 17.73 mm (P < 0.05), respectively, compared with the pretreatment data (0.062 ± 0.015 mm, 31.48 ± 18.21 mm). The reduction was more remarkable in group 2 compared to group 1.In group 1, the average diameter was 0.062 ± 0.013mm before and 0.056 ± 0.017mm after, the cumulative length of vessels was 38.66 ± 22.55mm before and 31.21 ± 17.30 after. In group 2, the date were 0.061 ± 0.016mm before and 0.029 ± 0.020mm after, 25.60 ± 8.95 mm before and 8.61 ± 8.26 mm. The reported complications included epithelial defect in four eyes, small white filaments in two eyes and corneal epithelial erosion in two eyes.

CONCLUSION

The PDT combined with subconjunctival injection of bevacizumab was effective for the chronic corneal neovascularization. A more promising treatment outcome was observed when PDT was performed at 60 min after intravenous injection of verteporfin with fluence of 150 J/cm2. No serious complications or systemic events were observed throughout the follow-up period.

Successful regression of newly formed corneal neovascularization by subconjunctival injection of bevacizumab in patients with chemical burns

Purpose

To investigate the effect and timing of subconjunctival bevacizumab injection on inhibiting corneal neovascularization (CorNV) in patients after chemical burns.

Methods

Patients with CorNV secondary to chemical burns were involved. Two subconjunctival injections of bevacizumab (2.5 mg/0.1 mL per involved quadrant) with an interval of 4 weeks were administered, and followed up a year. The area occupied by neovascular vessels (NA), accumulative neovascular length (NL), mean neovascular diameter (ND), best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were evaluated. Complication was also recorded.

Results

Eleven patients with CorNV were involved. Eight patients had a history of surgery (four had amniotic grafts, one had keratoplasty, and three had amniotic grafts and keratoplasty). Decreasing in NA, NL, and ND were statistically significant at each time point compared to the baseline (p < 0.01). CorNV that developed within 1 month was considerably regressed, and vessels with fibrovascular membranes were found to be narrower and shorter than pretreatment. BCVA improved in five patients (from one to five lines), remained unchanged in five patients, and decreased in one patient compared to pretreatment.

Conclusion

Subconjunctival bevacizumab injection has a particular potential for the regression of CorNV, especially newly formed within 1 month in patients after chemical burns.

Effect of Bevacizumab on the Viability and Metabolism of Human Corneal Epithelial and Endothelial Cells: An In Vitro Study

Purpose

To examine the cytotoxic effects of bevacizumab on the viability and metabolism of human corneal epithelial cells (HCEpCs) and human corneal endothelial cells (HCEnCs), as well as human retinal pigment epithelial (ARPE-19) cells for comparison.

Methods

Immortalized cell lines of HCEpCs, HCEnCs, and ARPE-19 cells were exposed to clinically relevant concentrations of bevacizumab (0.313-5.00 mg/mL). The ApoTox-Glo Triplex Assay was used to assess cell viability, cytotoxicity, and apoptosis, and the Mitochondrial ToxGlo Assay was used to assess cell membrane integrity and adenosine triphosphate (ATP) levels after a 24-hour treatment period.

Results

Across all three cell types, we observed similar results of a decrease in cell viability at 5.00 mg/mL (P < 0.05) and an increase in cytotoxicity at 5.00 mg/mL (P < 0.05), whereas apoptotic activity remained unchanged (P > 0.05), which is a profile consistent with cells undergoing primary necrosis at high concentrations. Additionally, cell membrane integrity was compromised at 5.00 mg/mL (P < 0.05), whereas no decrease in ATP levels were observed (P > 0.05). Thus, no interference with mitochondrial oxidative phosphorylation in ATP production was seen, and the cells were able to maintain normal metabolic levels at high concentrations of bevacizumab.

Conclusions

HCEpCs, HCEnCs, and ARPE-19 cells experience a decrease in viability and undergo primary necrosis when exposed to bevacizumab at a concentration of 5.00 mg/mL; however, they are able to maintain normal metabolism and mitochondrial function at the high concentrations used for the treatment of corneal neovascularization.

Translational Relevance

This study provides safety data on the concentrations of bevacizumab injected intravitreally and complements clinical data showing toxicity of topical bevacizumab on corneal epithelial and endothelial cells.

The effect of intravitreal anti-vascular endothelial growth factor injections on corneal endothelium in patients with diabetic macular oedema

PURPOSE

To evaluate the characteristics of corneal parameters in patients with diabetic macular oedema (DME) treated with intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections.

METHODS

Participants in this study were 36 patients with DME, treated with either intravitreal ranibizumab (n = 16) or aflibercept (n = 20). All participants underwent best-corrected visual acuity (BCVA) measurement, optical coherence tomography and non-contact specular microscopy to evaluate corneal endothelium parameters (endothelial cell density-ECD, hexagonality, coefficient of variation of the cell size and central corneal thickness-CCT), at baseline and at months 6 and 12 after the first intravitreal injection. Comparisons between baseline and months 6 and 12 were performed.

RESULTS

There was no statistically significant difference regarding ECD, hexagonality, coefficient of variation of the cell size and CCT at month 6 and 12 post initial injection compared to baseline in patients with DME. BCVA improved significantly at month 6 and 12 compared to baseline (p < 0.001 for both comparisons). Central retinal thickness was significantly reduced at month 6 and 12 compared to baseline (p < 0.001 for both comparisons).

CONCLUSION

Intravitreal anti-VEGF injections in patients with DME were found not to affect corneal parameters, namely ECD, hexagonality, coefficient of variation of the cell size and CCT at the long-term follow-up of 12 months.

Bevacizumab Induces Upregulation of Keratin 3 and VEGFA in Human Limbal Epithelial Cells in Vitro

Topical application of vascular endothelial growth factor A (VEGFA) inhibitors including Bevacizumab is used for antiangiogenic therapy at the ocular surface. While clinical studies have suggested that this approach is well-tolerated, the effect of the drug on limbal epithelial stem cells has not been studied. In this study, the effect of Bevacizumab on phenotype and functionality of putative limbal epithelial stem cells (SC) was investigated. The effect of Bevacizumab on human limbal epithelial cells was assessed in terms of metabolic activity and scratch wound closure. The different treatment groups featured no difference in proliferation and colony forming efficiency (CFE) of limbal epithelial cells or their putative SC marker expression. A significant delay in scratch closure of all the Bevacizumab-treated groups was detected at 4 h. RNA and protein quantification indicated a dose-responsive increase of keratin 3. VEGFA RNA expression also increased while VEGFC and D as well as VEGFR1, 2 and 3 were unchanged. This study highlights previously unknown effects of Bevacizumab on cultured putative limbal epithelial SC: a dose-related increase of keratin 3, an increase in VEGFA as well as a delay in scratch wound closure. These in vitro data should be considered when using Bevacizumab in the context of limbal epithelial SC transplantation.

A label-free approach to detect cell viability/cytotoxicity based on intracellular xanthine/guanine by electrochemical method

INTRODUCTION

Cell viability and cytotoxicity is one of the most important toxicology indicators. In this study, an electrochemical method for detecting cell viability and cytotoxicity was discussed with the intracellular small molecule metabolite purines as indexes.

METHODS

The electrochemical behaviors of Balb/c 3T3, CHO, PC-12 and V79 cell suspensions were studies by cyclic voltammetry, and cell viability and cytotoxicity of four cell lines were compared by electrochemical, cell counting, 3-(4,5-dimethyl-2-Thiazyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) and trypan blue exclusion methods.

RESULTS

Four cell lines all showed an oxidation peak derived from mixture of xanthine and guanine at about 0.7 V. Using intracellular xanthine and guanine as index, the electrochemical method could not only describe the cell growth curves of four cell lines, but also reflect the changes of cell viability at various phases of the cell growth prior to the counting method. Compared with MTT, cell counting and trypan blue staining methods, the electrochemical method could detect the cytotoxicity of carcinogen earlier and more sensitively.

DISCUSSION

The electrochemical method could track the change of intracellular xanthine and guanine contents, and used it as index to detect cell viability and cytotoxicity at the molecular level without markers, showing greater advantages over the method with apparent cell proliferation as the endpoint.

Short-term regression of corneal neovascularization with combination therapy of argon green laser photocoagulation and subconjunctival bevacizumab

We present a case of a 49 year-old male with history of corneal neovascularization secondary to herpes zoster keratitis that clinically and subjectively improved for approximately 4 months after treatment with argon laser photocoagulation to feeder vessels and subconjunctival bevacizumab. This is the first report in the literature that describes this novel combination treatment for corneal neovascularization in the setting of varicella-zoster virus and discusses its efficacy.

Effects of ranibizumab (Lucentis®) and bevacizumab (Avastin®) on human corneal endothelial cells

Background

Ingrowth of newly formed blood and lymph vessels (angiogenesis) from the limbus region into the cornea can be treated successfully by subconjunctival application of antiangiogenic agents. Currently, there are several angiogenesis inhibitors from various manufacturers available, such as vascular endothelial growth factor (VEGF) antibodies. The aim of the study was to investigate potential cytotoxic effects of two anti-VEGF agents, ranibizumab (Lucentis®) and bevacizumab (Avastin®) on the human corneal endothelium.

Methods

Human donor corneas, not suitable for corneal transplantation, were organ-cultured in the presence of either ranibizumab (Lucentis®) or bevacizumab (Avastin®) at different concentrations (group 1: 250 μg / ml, group 2: 25 μg / ml, group 3: 2.5 μg / ml) for a period of up to 4 weeks. Microscopic imaging for endothelial cell counting, detection of morphologic alterations of the endothelium, and molecular biology testing (Enzyme-linked Immunosorbent Assay [ELISA]) for metabolic changes was performed.

Results

Background-corrected results showed neither a significant lactate dehydrogenase (LDH) change with increasing culturing time nor a significant difference between ranibizumab (Lucentis®) and bevacizumab (Avastin®) treatment. The endothelial cell density revealed also no statistically significant difference between the two treatment groups with ranibizumab (Lucentis®) and bevacizumab (Avastin®) at all concentrations tested in this study.

Conclusions

In this study, the anti-angiogenic agents ranibizumab (Lucentis®) and bevacizumab (Avastin®) demonstrated no cytotoxic effects on the corneal endothelium of human organ-cultured donor corneas over the limited study time period of 4 weeks. However, based on the study design (in-vitro) and the limited follow-up period, no conclusions on potential long-term effects can be drawn.

Inhibition of proliferation of retinal vascular endothelial cells more effectively than choroidal vascular endothelial cell proliferation by bevacizumab

AIM

To evaluate the differential inhibitory effects of bevacizumab on cell proliferation of vascular endothelial growth factor (VEGF)-stimulated choroidal vascular endothelial cells (CVECs) and retinal vascular endothelial cells (RVECs) in vitro.

METHODS

VEGF (400 ng/mL) enriched CVECs and RVECs were treated with escalating doses of bevacizumab (0.1, 0.5, 1, 1.5 and 2 mg/mL). Cell proliferation changes were analyzed with WST-1 assay and trypan blue exclusion assay at 48, 72h and 1wk. Morphological changes were recorded with bright field microscopy.

RESULTS

VEGF enriched RVECs showed significantly more decline of cell viability than CVECs after bevacizumab treatment. One week after treatment, RVEC cell proliferation decreased by 29.7%, 37.5%, 52.8%, 35.9% and 45.6% at 0.1, 0.5, 1.0, 1.5 and 2 mg/mL bevacizumab respectively compared to CVEC proliferation decrease of 4.1%, 7.7%, 2.4%, 4.1% and 17.7% (P<0.05) by WST-1 assay. Trypan blue exclusion assay also revealed similar decrease in RVEC proliferation of 20%, 60%, 73.3%, 80% and 93.3% compared to CVEC proliferation decrease of 4%, 12%, 22.9%, 16.7% and 22.2% respectively (P<0.05). The maximum differential effect between the two cell types was observed at bevacizumab doses of 1.0 and 1.5 mg/mL at all time points. RVECs were 22 fold more sensitive (P<0.01) compared to CVECs (52.8% vs 2.4%) at concentration of 1.0 mg/mL, and 8.7 fold more at 1.5 mg/mL (35.9% vs 4.1%) 1wk after treatment (P<0.05 respectively).

CONCLUSION

VEGF-enriched RVECs are more susceptible to bevacizumab inhibition than CVECs at clinically used dosage of 1.25 mg and this differential sensitivity between two cell types should be taken into consideration in dosage selection.

Effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab) on lens epithelial cells

The molecular and cellular effects of anti-vascular endothelial growth factor monoclonal antibody (bevacizumab) on lens epithelial cells (LECs) were examined using both an immortalized human lens epithelial cell line and a porcine capsular bag model. After treatment with various concentrations of bevacizumab, cell viability and proliferation patterns were evaluated using the water-soluble tetrazolium salt assay and 5-bromo-2′-deoxyuridine enzyme-linked immunosorbent assay, respectively. The scratch assay and Western blot analysis were employed to validate the cell migration pattern and altered expression levels of signaling molecules related to the epithelial–mesenchymal transition (EMT). Application of bevacizumab induced a range of altered cellular events in a concentration-dependent manner. A 0.1–2 mg/mL concentration demonstrated dose-dependent increase in proliferation and viability of LECs. However, 4 mg/mL decreased cell proliferation and viability. Cell migrations displayed dose-dependent retardation from 0.1 mg/mL bevacizumab treatment. Transforming growth factor-β2 expression was markedly increased in a dose-dependent manner, and α-smooth muscle actin, matrix metalloproteinase-9, and vimentin expression levels showed dose-dependent changes in a B3 cell line. Microscopic observation of porcine capsular bag revealed changes in cellular morphology and a decline in cell density compared to the control after 2 mg/mL treatment. The central aspect of posterior capsule showed delayed confluence, and the factors related to EMT revealed similar expression patterns to those identified in the cell line. Based on these results, bevacizumab modulates the proliferation and viability of LECs and induces morphological alterations through the modulation of expression patterns of specific factors related to the EMT.

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.

Effect of Bevacizumab on Human Tenon's Fibroblasts Cultured from Primary and Recurrent Pterygium

The purpose of this study was to compare the inhibitory effect of bevacizumab on human Tenon's fibroblasts (HTFs) cultured from primary and recurrent pterygium. Cultured HTFs were exposed to 2.0, 5.0, 7.5, and 15.0 mg/mL concentration of bevacizumab for 24 hours. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase leakage assays were then performed to assess fibroblast metabolism and viability. The matrix metalloproteinase (MMP), procollagen type I C terminal propeptide (PIP), and laminin immunoassays were performed to examine extracellular matrix production. Changes in cellular morphology were examined by phase-contrast and transmission electron microscopy. Both metabolic activity and viability of primary and recurrent pterygium HTFs were inhibited by bevacizumab in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. Both types of HTFs had significant decreases in MMP-1, PIP, and laminin levels. Distinctly, the inhibitory effect of bevacizumab on MMP-1 level related with collagenase in primary pterygium HTFs was significantly higher than that of recurrent pterygium. Significant changes in cellular density and morphology both occurred at bevacizumab concentrations greater than 7.5 mg/mL. Only primary pterygium HTFs had a reduction in cellular density at a bevacizumab concentration of 5.0 mg/mL. Bevacizumab inhibits primary and recurrent pterygium HTFs in a dose-dependent manner, especially at concentrations greater than 7.5 mg/mL. As the primary HTFs produces larger amounts of MMP-1 compared to recurrent HTFs, significant reduction in MMP-1 level in primary pterygium HTFs after exposure to bevacizumab is likely to be related to the faster cellular density changes in primary pterygium HTFs.

Anterior segment uses of bevacizumab

PURPOSE OF REVIEW

A significant recent advancement in the treatment of neovascularization of the anterior segment of the eye is the development of antivascular endothelial growth factor (anti-VEGF) therapeutic agents.We present a review of the current knowledge on anti-VEGF therapy with bevacizumab for anterior segment neovascularization.

RECENT FINDINGS

A review of the recent peer-reviewed literature reveals an increasing number of experimental and clinical studies on the use of Avastin in both human and animal eye models. Although the numbers are still relatively small, the evidence suggests that bevacizumab may be effective in the treatment of corneal and iris neovascularization. Its effect on primary and recurrent pterygium is more controversial. In general, achievement of vessels regression is usually partial, and recurrence may occur after cessation of treatment. Response to treatment is affected by the chronicity of vessels, their extent, the cause for blood vessels formation, and the route of administration.

SUMMARY

Effective short-term response together with high patient tolerance to local bevacizumab therapy offer encouraging results for the management of anterior segment neovascular disorders. Although statistically significant regression of vessels has been documented in many studies, the clinical significance of this finding is still a subject of debate.

Corneal neovascularization: an anti-VEGF therapy review

Corneal neovascularization is a serious condition that can lead to a profound decline in vision. The abnormal vessels block light, cause corneal scarring, compromise visual acuity, and may lead to inflammation and edema. Corneal neovascularization occurs when the balance between angiogenic and antiangiogenic factors is tipped toward angiogenic molecules. Vascular endothelial growth factor (VEGF), one of the most important mediators of angiogenesis, is upregulated during neovascularization. In fact, anti-VEGF agents have efficacy in the treatment of neovascular age-related macular degeneration, diabetic retinopathy, macular edema, neovascular glaucoma, and other neovascular diseases. These same agents have great potential for the treatment of corneal neovascularization. We review some of the most promising anti-VEGF therapies, including bevacizumab, VEGF trap, siRNA, and tyrosine kinase inhibitors.

Effects of subconjunctival bevacizumab on corneal neovascularization: results of a prospective study

PURPOSE

To evaluate the effect of subconjunctival bevacizumab injections in patients with corneal neovascularization resulting from different ocular surface disorders.

METHODS

Prospective case series. Twelve eyes of 11 patients with corneal neovascularization caused by different ocular surface disorders, such as healed corneal ulcers, long-standing chronic inflammatory diseases, and corneal ischemia secondary to burn, were included. All eyes received a single subconjunctival injection of 2.5 mg (0.1 mL) of bevacizumab. Morphological changes in neovascularization were evaluated during 3 months using slit-lamp biomicroscopy, corneal digital photography, and computer-assisted semiautomatic analysis of corneal neovascularization area.

RESULTS

Recession of corneal vessels was observed in all eyes at 1 week postinjection. The surface of the neovascular tree continued to decrease noticeably for 1 month and then increased again for the remainder of the follow-up period. The corneal neovascularization area amounted to 11.25 ± 4.49% of the corneal surface preinjection, compared with 8.44 ± 3.37% postinjection (P = 0.02), reflecting a mean decrease in corneal neovascularization of 25%. No local or systemic adverse events possibly related to subconjunctival bevacizumab injection were observed.

CONCLUSIONS

Short-term results suggest that subconjunctival bevacizumab can be used safely and effectively for corneal neovascularization resulting from different ocular surface disorders, providing an additional strategy to improve success of corneal grafts.

Larger therapeutic window for steroid versus VEGF-A inhibitor in inflammatory angiogenesis: surprisingly similar impact on leukocyte infiltration

PURPOSE

The current treatments against inflammatory angiogenesis are steroids and anti-VEGF-A, such as dexamethasone and bevacizumab, respectively. However, the therapeutic windows for dexamethasone and bevacizumab against inflammatory angiogenesis are unknown.

METHODS

To investigate the therapeutic windows for dexamethasone and bevacizumab, we used the corneal pocket assay. IL-1β pellets were implanted in corneas of BALB/c mice that were then treated with dexamethasone or bevacizumab at different time points. Angiogenesis (area, number of vessels, and sprouting) was quantitated at various time points after implantation. Nuclear Factor-κB (NF-κB) signaling and leukocyte accumulation in inflammatory angiogenesis were examined by Western blotting, by immunohistochemistry, and in the authors' novel leukocyte transmigration assay.

RESULTS

Dexamethasone inhibited IL-1β-induced angiogenesis when treatment started 4 days after IL-1β implantation, while bevacizumab only inhibited angiogenesis by day 2 after implantation. Both bevacizumab and dexamethasone inhibited angiogenic sprouting. Interestingly, bevacizumab did not affect NF-κB activation, which is one of the main signaling targets for steroid action. The authors' new imaging approach revealed that bevacizumab and steroid treatment blocked leukocyte infiltration into implanted corneas.

CONCLUSIONS

VEGF-A inhibition affected angiogenic sprouting, while it was not effective against matured vessels. Both dexamethasone and bevacizumab inhibited leukocyte transmigration from angiogenic vessels; however, dexamethasone had a larger therapeutic window. These insights improve the treatment strategy in angiogenic disorders.

The effect of subconjunctival bevacizumab on corneal neovascularization, inflammation and re-epithelization in a rabbit model

PURPOSE

To evaluate the use of subconjunctival bevacizumab on corneal neovascularization in an experimental rabbit model for its effect on vessel extension, inflammation, and corneal epithelialization.

METHODS

In this prospective, randomized, blinded, experimental study, 20 rabbits were submitted to a chemical trauma with sodium hydroxide and subsequently divided into two groups. The experimental group received a subconjunctival injection of bevacizumab (0.15 m; 3.75 mg), and the control group received an injection of 0.15 ml saline solution. After 14 days, two blinded digital photograph analyses were conducted to evaluate the inflammation/diameter of the vessels according to pre-established criteria. A histopathological analysis of the cornea evaluated the state of the epithelium and the number of polymorphonuclear cells.

RESULTS

A concordance analysis using Kappa's statistic showed a satisfactory level of agreement between the two blinded digital photography analyses. The neovascular vessel length was greater in the control group (p<0.01) than in the study group. However, the histopathological examination revealed no statistically significant differences between the groups in terms of the state of the epithelium and the number of polymorphonuclear cells.

CONCLUSIONS

Subconjunctival bevacizumab inhibited neovascularization in the rabbit cornea. However, this drug was not effective at reducing inflammation. The drug did not induce persistent corneal epithelial defects.

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.

Bleb morphology and vascularity after trabeculectomy with intravitreal ranibizumab: a pilot study

PURPOSE

To investigate outcomes after trabeculectomy using intraoperative intravitreal ranibizumab and topical mitomycin C (MMC) vs MMC alone.

DESIGN

Prospective randomized single-site pilot study.

METHODS

Patients diagnosed with primary open-angle glaucoma were randomized 1:1 to either combination intravitreal ranibizumab 0.5 mg and topically applied MMC (0.4 mg/mL for 2 min) or MMC (0.4 mg/mL for 2 min) therapy alone at time of trabeculectomy surgery. The primary endpoint measured was bleb morphology and vascularity using the Moorfields Bleb Grading System. Unqualified success was defined as postoperative intraocular pressure (IOP) of >5 and <22 mm Hg and a 30% decrease from baseline without use of postoperative hypotensive drops. Qualified success was defined as postoperative IOP of >5 and <22 mm Hg and a 30% decrease from baseline with use of postoperative hypotensive drops.

RESULTS

Ten patients were randomized to either standard trabeculectomy with MMC (Group A) or trabeculectomy with intravitreal ranibizumab and MMC (Group B). All patients completed the study and were classified as unqualified successes. There were statistically significant differences in peripheral bleb area (P = .02), peripheral bleb vascularity (P = .02), and non-bleb-related peripheral conjunctiva vascularity (P = .0003), with Group B exhibiting more diffuse blebs with a lower degree of vascularity.

CONCLUSIONS

Combination intravitreal ranibizumab and topical MMC at time of trabeculectomy resulted in more diffuse blebs with less vascularity when compared to use of topical MMC alone. Further studies are planned to better understand the utility of anti-vascular endothelial growth factor agents as modulators of wound healing post trabeculectomy.