Topical bevacizumab in the treatment of corneal neovascularization: results of a prospective, open-label, noncomparative study

Cornea-Derived Mesenchymal Stromal Cells Therapeutically Modulate Macrophage Immunophenotype and Angiogenic Function

Macrophages are crucial drivers of inflammatory corneal neovascularization and thus are potential targets for immunomodulatory therapies. We hypothesized that therapeutic use of cornea-derived mesenchymal stromal cells (cMSCs) may alter the function of macrophages. We found that cMSCs can modulate the phenotype and angiogenic function of macrophages. In vitro, cMSCs induce apoptosis of macrophages while preferentially promoting a distinct CD14^hi CD16^hi CD163^hi CD206^hi immunophenotype that has significantly reduced angiogenic effects based on in vitro angiogenesis assays. In vivo, application of cMSCs to murine corneas after injury leads to reduced macrophage infiltration and higher expression of CD206 in macrophages. Macrophages cocultured ("educated") by cMSCs express significantly higher levels of anti-angiogenic and anti-inflammatory factors compared with control macrophages. In vivo, injured corneas treated with cMSC-educated macrophages demonstrate significantly less neovascularization compared with corneas treated with control macrophages. Knocking down the expression of pigment epithelial derived factor (PEDF) in cMSCs significantly abrogates its modulating effects on macrophages, as shown by the reduced rate of apoptosis, decreased expression of sFLT-1/PEDF, and increased expression of vascular endothelial growth factor-A in the cocultured macrophages. Similarly, cMSCs isolated from PEDF knockout mice are less effective compared with wild-type cMSCs at inhibiting macrophage infiltration when applied to wild-type corneas after injury. Overall, these results demonstrate that cMSCs therapeutically suppress the angiogenic capacity of macrophages and highlight the role of cMSC secreted PEDF in the modulation of macrophage phenotype and function. Stem Cells 2018;36:775-784.

Selective IKK2 inhibitor IMD0354 disrupts NF-κB signaling to suppress corneal inflammation and angiogenesis

Corneal neovascularization is a sight-threatening condition caused by angiogenesis in the normally avascular cornea. Neovascularization of the cornea is often associated with an inflammatory response, thus targeting VEGF-A alone yields only a limited efficacy. The NF-κB signaling pathway plays important roles in inflammation and angiogenesis. Here, we study consequences of the inhibition of NF-κB activation through selective blockade of the IKK complex IκB kinase β (IKK2) using the compound IMD0354, focusing on the effects of inflammation and pathological angiogenesis in the cornea. In vitro, IMD0354 treatment diminished HUVEC migration and tube formation without an increase in cell death and arrested rat aortic ring sprouting. In HUVEC, the IMD0354 treatment caused a dose-dependent reduction in VEGF-A expression, suppressed TNFα-stimulated expression of chemokines CCL2 and CXCL5, and diminished actin filament fibers and cell filopodia formation. In developing zebrafish embryos, IMD0354 treatment reduced expression of Vegf-a and disrupted retinal angiogenesis. In inflammation-induced angiogenesis in the rat cornea, systemic selective IKK2 inhibition decreased inflammatory cell invasion, suppressed CCL2, CXCL5, Cxcr2, and TNF-α expression and exhibited anti-angiogenic effects such as reduced limbal vessel dilation, reduced VEGF-A expression and reduced angiogenic sprouting, without noticeable toxic effect. In summary, targeting NF-κB by selective IKK2 inhibition dampened the inflammatory and angiogenic responses in vivo by modulating the endothelial cell expression profile and motility, thus indicating an important role of NF-κB signaling in the development of pathologic corneal neovascularization.

Therapeutic approaches for corneal neovascularization

Angiogenesis refers to new blood vessels that originate from pre-existing vascular structures. Corneal neovascularization which can lead to compromised visual acuity occurs in a wide variety of corneal pathologies. A large subset of measures has been advocated to prevent and/or treat corneal neovascularization with varying degrees of success. These approaches include topical corticosteroid administration, laser treatment, cautery, and fine needle diathermy. Since the imbalance between proangiogenic agents and antiangiogenic agents primarily mediate the process of corneal neovascularization, recent therapies are intended to disrupt the different steps in the synthesis and actions of proangiogenic factors. These approaches, however, are only partially effective and may lead to several side effects. The aim of this article is to review the most relevant treatments for corneal neovascularization available so far.

Growth inhibition of formed corneal neovascularization following Fosaprepitant treatment

PURPOSE

The aim of this study was to test the efficacy of Neurokinin-1 Receptor (NK-1R) antagonist -Fosaprepitant- in inducing regression of established corneal neovascularization (CNV).

METHODS

Twenty C57BL/6 mice underwent alkali burn. Seven days later, when corneal neovessels had developed, they received Fosaprepitant 10 mg/ml, administered topically six times a day in the right eye for 10 days. In parallel, a group of 20 causticated mice was treated with normal saline, as control. A second independent experiment was also performed (n = 10/group). Finally, ten healthy mice received the same topical treatment for 10 days to evaluate Fosaprepitant safety. Haemangiogenesis and lymphangiogenesis were measured by means of vesselj plugin (imagej). Secondary endpoints, such as leucocyte infiltration, corneal opacity and corneal fluorescein staining were also evaluated. Inflammatory cell composition was assessed by flow cytometry. Differences between groups were assessed using unpaired t-test, Mann-Whitney U-test or two-way anova, as appropriate.

RESULTS

Topical Fosaprepitant administration induced a significant reduction of (i) CD31⁺ blood corneal neovessels (-27%, p = 0.0132), (ii) LYVE1⁺ lymphatic corneal neovessels (-31%, p = 0.0118) and (iii) CD45⁺ leucocyte infiltration (-36%; p = 0.0237). The second independent experiment confirmed these data. Moreover, Fosaprepitant-treated corneas showed a reduction in opacity, no impairment in corneal fluorescein staining and decreased infiltration of neutrophils (-72%, p < 0.05) and macrophages (-75%, p < 0.01). Finally, topical Fosaprepitant was not toxic to the ocular surface: no signs of conjunctivitis, opacity, perforations or corneal fluorescein staining were detected. Similarly, corneal TUJ1⁺ nerve density was not affected.

CONCLUSIONS

Our data suggest that NK-1R antagonists, such as Fosaprepitant, could be a new, promising therapeutic tool to inhibit CNV after this has been established.

Genome-wide expression differences in anti-Vegf and dexamethasone treatment of inflammatory angiogenesis in the rat cornea

Angiogenesis as a pathological process in the eye can lead to blindness. In the cornea, suppression of angiogenesis by anti-VEGF treatment is only partially effective while steroids, although effective in treating inflammation and angiogenesis, have broad activity leading to undesirable side effects. In this study, genome-wide expression was investigated in a suture-induced corneal neovascularization model in rats, to investigate factors differentially targeted by dexamethasone and anti-Vegf. Topical treatment with either rat-specific anti-Vegf, dexamethasone, or normal goat IgG (sham) was given to sutured corneas for 48 hours, after which in vivo imaging, tissue processing for RNA microarray, and immunofluorescence were performed. Dexamethasone suppressed limbal vasodilation (P < 0.01) and genes in PI3K-Akt, focal adhesion, and chemokine signaling pathways more effectively than anti-Vegf. The most differentially expressed genes were confirmed by immunofluorescence, qRTPCR and Western blot. Strong suppression of Reg3g and the inflammatory chemokines Ccl2 and Cxcl5 and activation of classical complement pathway factors C1r, C1s, C2, and C3 occurred with dexamethasone treatment, effects absent with anti-Vegf treatment. The genome-wide results obtained in this study provide numerous potential targets for specific blockade of inflammation and angiogenesis in the cornea not addressed by anti-Vegf treatment, as possible alternatives to broad-acting immunosuppressive therapy.

Suppression of Allograft Rejection with Soluble VEGF Receptor 2 Chimeric Protein in a Mouse Model of Corneal Transplantation

When a transparent cornea becomes opaque due to infectious diseases, trauma, or ophthalmic surgery, the impaired cornea is replaced with a donor cornea to improve visual function. In this corneal transplantation, the graft survival rate is comparatively high, partly because of lacking vascular and lymphatic vessel in cornea. However, the transplanted corneas sometimes become opaque if allograft rejection occurs. Suppression of allograft rejection is critical for favorable outcomes of corneal transplantation. The essential effects of endogenous monomeric soluble vascular endothelial growth factor receptors (VEGFRs) 1 and 2 have been reported in corneal angiogenesis and lymphangiogenesis. This study investigated the effects of dimeric soluble VEGFR2/Fc chimera protein on corneal allograft rejection for future clinical application. Allogeneic full-thickness corneal transplantation was performed in C57BL/6 to BALB/c mice. The recipients were treated by intrastromal injection of soluble VEGFR1/Fc chimera (sR1/Fc group), soluble VEGFR2/Fc chimera (sR2/Fc group), or human IgG1/Fc protein (IgG/Fc group) at 0, 7, and 14 days after surgery. Both hemangiogenesis and lymphangiogenesis were significantly suppressed in the corneas of the sR2/Fc group compared with the IgG/Fc group. All grafts failed due to corneal wound rupture in the sR1/Fc group. In the sR2/Fc group, respective donor-derived MHC class II(+)/CD11c(+) cells and CD11b-positive macrophage infiltration were reduced in the DLNs and the corneas showing a negative delayed-type hypersensitivity, compared with the IgG/Fc group. Our findings demonstrate that soluble VEGFR2/Fc chimera protein efficiently suppresses corneal allo-rejection, while reducing hemangiogenesis and lymhangiogenesis, and immune-competent cell-trafficking and may be a powerful tool for corneal allograft survival.

Topical versus subconjunctival anti-vascular endothelial growth factor therapy (Bevacizumab, Ranibizumab and Aflibercept) for treatment of corneal neovascularization

In order to evaluate the effect of topical and subconjunctival anti-vascular endothelial growth factor (anti-VEGF) therapy, Ranibizumab, Bevacizumab and Aflibercept as a therapy for corneal neovascularization (NV) treatment, the aim of this study was to review all data related to some of anti-VEGF as a promising therapies for corneal NV treatment. Corneal NV is a dangerous condition leading to a marked reduction in vision due to angiogenesis of abnormal vessels that block light. During the recent years, we have recognized new drug proliferation for corneal NV treatment. Recently, anti-VEGF therapies are one of the most important drugs used for corneal NV treatment. Several growth factors are involved in angiogenesis. The most important growth factor in corneal angiogenesis is VEGF. VEGF can be considered as key mediators in corneal angiogenesis. It is upregulated during corneal NV. In fact, anti-VEGF therapies have shown efficacy in attenuation of corneal NV in both animal models and clinical trials. A promising therapeutic success has been achieved using antibodies directed against VEGF. Bevacizumab has demonstrated efficacy and efficiency in the treatment of different neo-vascular ocular diseases and it has partially reduced corneal NV through different routes of administrations: topical, subconjunctival, and intraocular application. A similar efficacy to bevacizumab profiles in the treatment of neo-vascular age-related macular degeneration was induced by ranibizumab. Moreover, at worse levels of initial visual acuity of diabetic macular edema, aflibercept was more effective at improving vision. Anti-VEGF agents (Bevacizumab, Ranibizumab and Aflibercept) seem to have a higher efficiency and efficacy for corneal NV treatment. Both subconjunctival therapy and topical therapy of bevacizumab prohibit corneal NV, while early treatment with subconjunctival administration of ranibizumab may successfully reduce corneal NV. Therefore, establishment of safe doses is highly important before these drugs can be involved in the clinical setting. Further investigations and studies are highly warranted to adjust the dose and route of administration for the antibodies directed against VEGF to be the key therapeutic agents in the corneal NV treatment.

Efficacy of Subconjunctival Aflibercept Versus Bevacizumab for Prevention of Corneal Neovascularization in a Rat Model

PURPOSE

We aimed to evaluate the efficacy of subconjunctival aflibercept, a vascular endothelial growth factor trap compound, for the treatment of corneal neovascularization in a rat model.

METHODS

Chemical burn was produced in the central cornea of 31 male Sprague-Dawley rats. Animals were randomized to receive treatment with subconjunctival injection of 0.08 mL aflibercept (25 mg/mL), 0.05 mL bevacizumab (25 mg/mL), or 0.05 mL physiologic saline. Corneal neovascularization was evaluated on postinjury days 1, 3, 7, 9, and 13 by corneal photographs. The rats were killed on day 21 and samples were collected for histological and flat-mount immunofluorescence analyses.

RESULTS

In all rats, vascular sprouting began on day 3, reached maximum density on days 7-9, and spontaneously regressed thereafter. Mean burn area in the central cornea comprised ∼15% of the total corneal area. The aflibercept group had a significantly smaller relative area of neovascularization than both control group (P < 0.05, 12.27 ± 9.91, 29.66 ± 9.96 days 7) and bevacizumab group (P < 0.05, 12.27 ± 9.91, 21.27 ± 8.19 days 7 and 15.5 ± 10.25, 32.38 ± 9.44 days 9; Mann-Whitney test). On histological study, hematoxylin and eosin staining revealed blood vessels extending to the central cornea in the control and bevacizumab groups and limited to the periphery in the aflibercept group. Immunofluorescence study with an endothelial marker revealed a smaller area of staining in the aflibercept group.

CONCLUSIONS

Aflibercept effectively inhibits corneal neovascularization in a rat model of chemical burn-induced neovascularization and warrants further study for potential use in humans.

Update on the Management of High-Risk Penetrating Keratoplasty

PURPOSE OF REVIEW

In this article, we review the indications and latest management of high-risk penetrating keratoplasty.

RECENT FINDINGS

Despite the immune-privilege status of the cornea, immune-mediated graft rejection still remains the leading cause of corneal graft failure. This is particularly a problem in the high-risk graft recipients, namely patients with previous graft failure due to rejection and those with inflamed and vascularized corneal beds. A number of strategies including both local and systemic immunosuppression are currently used to increase the success rate of high-risk corneal grafts. Moreover, in cases of limbal stem cell deficiency, limbal stem cells transplantation is employed.

SUMMARY

Corticosteroids are still the top medication for prevention and treatment in cases of corneal graft rejection. Single and combined administration of immunosuppressive agents e.g. tacrolimus, cyclosporine and mycophenolate are promising adjunctive therapies for prolonging graft survival. In the future, cellular and molecular therapies should allow us to achieve immunologic tolerance even in high-risk grafts.

Preparation of arginine-glycine-aspartic acid-modified biopolymeric nanoparticles containing epigalloccatechin-3-gallate for targeting vascular endothelial cells to inhibit corneal neovascularization

Neovascularization (NV) of the cornea can disrupt visual function, causing ocular diseases, including blindness. Therefore, treatment of corneal NV has a high public health impact. Epigalloccatechin-3-gallate (EGCG), presenting antiangiogenesis effects, was chosen as an inhibitor to treat human vascular endothelial cells for corneal NV treatment. An arginine–glycine–aspartic acid (RGD) peptide–hyaluronic acid (HA)-conjugated complex coating on the gelatin/EGCG self-assembly nanoparticles (GEH-RGD NPs) was synthesized for targeting the α_vβ₃ integrin on human umbilical vein endothelial cells (HUVECs) in this study, and a corneal NV mouse model was used to evaluate the therapeutic effect of this nanomedicine used as eyedrops. HA-RGD conjugation via COOH and amine groups was confirmed by ¹H-nuclear magnetic resonance and Fourier-transform infrared spectroscopy. The average diameter of GEH-RGD NPs was 168.87±22.5 nm with positive charge (19.7±2 mV), with an EGCG-loading efficiency up to 95%. Images of GEH-RGD NPs acquired from transmission electron microscopy showed a spherical shape and shell structure of about 200 nm. A slow-release pattern was observed in the nanoformulation at about 30% after 30 hours. Surface plasmon resonance confirmed that GEH-RGD NPs specifically bound to the integrin α_vβ₃. In vitro cell-viability assay showed that GEH-RGD efficiently inhibited HUVEC proliferation at low EGCG concentrations (20 μg/mL) when compared with EGCG or non-RGD-modified NPs. Furthermore, GEH-RGD NPs significantly inhibited HUVEC migration down to 58%, lasting for 24 hours. In the corneal NV mouse model, fewer and thinner vessels were observed in the alkali-burned cornea after treatment with GEH-RGD NP eyedrops. Overall, this study indicates that GEH-RGD NPs were successfully developed and synthesized as an inhibitor of vascular endothelial cells with specific targeting capacity. Moreover, they can be used in eyedrops to inhibit angiogenesis in corneal NV mice.

Evaluation of topical bevacizumab as an adjunct to mitomycin C augmented trabeculectomy

Purpose

To investigate the safety and synergistic effect of topical bevacizumab after trabeculectomy surgery with mitomycin C (MMC).

Methods

In this prospective, non-randomized, comparative interventional study, 40 eyes from 40 patients with uncontrolled open-angle glaucoma were studied after they underwent primary trabeculectomy with mitomycin C (0.02% for 2 min). Following the procedure topical bevacizumab (4 mg/mL) was used for 2 weeks 4 times daily in group A. Patients in group B received routine postoperative care. The outcome measures were the intraocular pressure (IOP), number of anti-glaucoma medications, complications, and bleb evaluation.

Results

Of the 32 eyes that had at least 6 months follow-up, 16 were treated with adjuvant topical bevacizumab. The mean preoperative IOP in group A improved from 26.7 ± 9.3 mmHg with 2.8 ± 1.3 anti-glaucoma medications to 10.5 ± 2.8 mmHg with 0.7 ± 1 anti-glaucoma medications at last follow-up (P < 0.001). The mean preoperative IOP in group B improved from 21.8 ± 6.6 mmHg with 3 ± 0.8 anti-glaucoma medications to 11.4 ± 3.6 mmHg with 0.8 ± 1.2 anti-glaucoma medications at last follow-up (P < 0.001). There was an overall reduction of 54.4% and 43.7% in the IOP in groups A and B, respectively (P = 0.18). The cystic type of bleb was less common in group A (P = 0.043). One patient in group A developed a streptococcal corneal ulcer 1.5 months after surgery.

Conclusion

Administration of topical bevacizumab 4 mg/ml for two weeks following trabeculectomy with mitomycin-C did not significantly affect the IOP trend, but significantly decreased the cystic bleb formation in short-term follow-up.

Current and Upcoming Therapies for Ocular Surface Chemical Injuries

Chemical injuries frequently result in vision loss, disfigurement, and challenging ocular surface complications. Acute interventions are directed at decreasing the extent of the injury, suppressing inflammation, and promoting ocular surface re-epithelialization. Chronically, management involves controlling inflammation along with rehabilitation and reconstruction of the ocular surface. Future therapies aimed at inhibiting neovascularization and promoting ocular surface regeneration should provide more effective treatment options for the management of ocular chemical injuries.

Intrastromal Injection of Bevacizumab in the Management of Corneal Neovascularization: About 25 Eyes

Introduction. Corneal neovessels are a major risk factor for corneal graft rejection, due to the loss of the immune privilege. The purpose of this study is to evaluate the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovascularization. Material and Methods. This is a prospective study that included 25 eyes of 22 patients with deep corneal neovessels, treated with intrastromal injections of bevacizumab. Results. The average age of patients was 31 years ranging from 16 to 44 years. The causes of neovascularization were dominated by herpetic keratitis (10 cases). The evolution was marked by complete regress of neovessels in 16 patients, partial regress in 6 cases, and reduced opacity and improved visual acuity in 5 patients. No side effects were noted. Discussion. Short-term results demonstrated the effectiveness of intrastromal injection of bevacizumab in the treatment of corneal neovessels. It may be an option or a complement to other useful treatments in stabilizing or improving vision. Conclusion. Bevacizumab is an effective additional treatment for the improvement of corneal transplants prognosis with preoperative corneal neovascularization.

[Management of corneal neovascularization prior to corneal transplantation: Report of 112 cases]

INTRODUCTION

The avascular nature of the cornea results from a balance between angiogenic factors and anti-angiogenic factors. Under pathological conditions, this homeostasis can be disturbed, resulting in the onset of corneal neovascularization. The purpose of our study was to report our experience in the management of corneal neovascularization prior to keratoplasty.

MATERIALS AND METHODS

This is a prospective study of 112 patients with corneal neovascularization and candidates for possible corneal transplant.

RESULTS

The average age of patients was 38 years, ranging from 15 to 72 years. The etiologies of neovascularization were dominated by ocular trauma (26.8 %). In total, 48.33 % of patients had superficial neovascularization, 18.52 % moderately deep and 33.2 % deep neovascularization. All patients received topical corticosteroids, 29.4 % received subconjunctival injections of bevacizumab, and 22.32 % intrastromal bevacizumab injections. Clinical course was marked by a decrease in the percentage of corneal neovascularization compared to the total corneal surface area, from 45 % (between 16 and 82 %) to 28 % (between 0 and 69 %) at Day 120. There was no statistically significant improvement in visual acuity.

DISCUSSION

Corneal neovascularization is a major risk factor for graft rejection; its management is crucial prior to every keratoplasty.

CONCLUSION

Corneal neovascularization can lead to increased risk of graft rejection. Proper management increases the success rate of penetrating keratoplasty.

Inhibition of Pathologic Corneal Neovascularization by Topical Application of a Novel Peptide In Vivo

PURPOSE

To investigate the antiangiogenic effect of topical application of H-KI20, a novel 20-amino acid peptide from the hepatocyte growth factor, on 2 animal models of corneal neovascularization (NV), and its possible toxic effects on the cornea and conjunctiva.

METHODS

The antiangiogenic effect of topical H-KI20 in vivo was studied on corneal NV induced by a mouse corneal micropocket assay and rat intrastromal suture model. In each model, H-KI20, scrambled control peptide H-KI20S, bevacizumab, and phosphate buffer solution (PBS) were applied topically 4 times a day. Corneal NV was examined, photographed, and analyzed. Histological analysis of the corneas was performed. Tear film breakup time and gross and histological examinations were used to study the possible toxicity of topical H-KI20.

RESULTS

Topical application of H-KI20 significantly inhibited corneal NV induced by vascular endothelial growth factor (VEGF), and intrastromal suture (P < 0.01 vs. the PBS group), and the area of corneal NV was suppressed by 80.3% and 83.6%, respectively (PBS group as 100%). No significant difference was found between 1.0 mg/mL H-KI20 and 10 mg/mL bevacizumab (P > 0.05). Both hematoxylin and eosin and CD34 staining revealed fewer new blood vessels in the H-KI20 and bevacizumab groups. Tear film breakup time and histological examinations showed that H-KI20 had no obvious toxic effects on the cornea and conjunctiva in vivo.

CONCLUSIONS

The novel peptide H-KI20 is an effective and safe inhibitor of corneal NV. It may provide a promising alternative for ocular topical antiangiogenic therapy.

A Drug Delivery System for Administration of Anti-TNF-α Antibody

PURPOSE

To describe the fabrication, evaluation, and preliminary in vivo safety of a new drug delivery system (DDS) for topical anti-TNF-α antibody administration.

METHODS

A DDS was fabricated using inverse template fabrication of a hydrophobic three-dimensional porous scaffold (100-300 μm in diameter porosity) loaded with 10% polyvinyl alcohol hydrogel carrying 5 mg/ml (weight/volume) of anti-TNF-α antibody. Drug-loaded DDS was sterilized with 25 kGy of gamma irradiation. Long-term in vitro antibody affinity and release was evaluated at room temperature or 37°C using enzyme-linked immunosorbent assay (ELISA) and protein fluorescence. In vivo clinical and histolopathological assessment was performed by subcutaneous implantation in BALB/c mice for 3 months.

RESULTS

Gamma irradiation, repeated dry/wet cycles, and storage at room temperature for 1 year or 37°C for 1 month had no deleterious effects on antibody affinity. Anti-TNF-α release was high during the first minutes of aqueous exposure, followed by stabilization and gradual, low-dose, antibody release over the next 30 days. Histopathologic evaluation of explanted DDS showed a fibrous pseudocapsule and a myxoid acute/chronic inflammation without granuloma formation surrounding the implants.

CONCLUSIONS

Sustained local delivery of anti-TNF-α antibody is feasible using the described DDS, which provides stability of the enclosed antibody for up to 1 year of storage. Preliminary results show good in vivo tolerance following subcutaneous placement for 3 months. The proposed fabrication and sterilization process opens new possibilities for the delivery of biologic agents to the anterior surface of the eye.

TRANSLATIONAL RELEVANCE

The described DDS will facilitate the treatment of ocular surface diseases amenable to biologic therapy.

[Current treatments for corneal neovascularization]

The extension of blood vessels into the normally avascular stroma defines corneal neovascularization. Though this phenomenon, pathophysiological and clinical features are well characterized, therapeutic modalities have been hindered by a lack of safe, efficacious and non-controversial treatments. In this literature review, we focus on available therapeutic options in light of recent evidence provided by animal and clinical studies. First, this review will focus on pharmacological treatments that target angiogenesis. The low cost and market availability of bevacizumab make it the first anti-angiogenic therapy choice, and it has demonstrable efficacy in reducing corneal neovascularization when administered topically or subconjunctivally. However, novel anti-angiogenic molecules targeting the intracellular pathways of angiogenesis (siRNA, antisense oligonucleotides) provide a promising alternative. Laser therapy (direct photocoagulation or photo-dynamic therapy) and fine needle diathermy also find a place in the treatment of stabilized corneal neovascularization alone or in association with anti-angiogenic therapy. Additionally, ocular surface reconstruction using amniotic membrane graft or limbal stem cell transplantation is essential when corneal neovascularization is secondary to primary or acquired limbal deficiency.

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.

Clinical use of Bevacizumab in treating refractory glaucoma

Bevacizumab is a recombinant humanized monoclonal antibody directed against vascular endothelial growth factor (VEGF). Though other VEGF inhibitors are being approved for the treatment of ophthalmological conditions, bevacizumab found its way into ophthalmology and clinical practice all around the world. The objective of this review is to present the ophthalmic dosage and administration pathways of bevacizumab in treating refractory glaucoma patients.

ABBREVIATIONS

VEGF = vascular endothelial growth factor, FDA = Food and Drug Administration, AMD = age-related macular degeneration.

Quantification of corneal neovascularization after ex vivo limbal epithelial stem cell therapy

AIM

To assess cultured limbal epithelial stem cell transplantation in patients with limbal stem cell deficiency by analyzing and quantifying corneal neovascularization.

METHODS

This retrospective, interventional case series included eight eyes with total limbal stem cell deficiency. Ex vivo limbal epithelial stem cells were cultured on human amniotic membrane using an animal-free culture method. The clinical parameters of limbal stem cell deficiency, impression cytology, and quantification of corneal neovascularization were evaluated before and after cultured limbal stem cell transplantation. The area of corneal neovascularization, vessel caliber (VC), and invasive area (IA) were analyzed before and after stem cell transplantation by image analysis software. Best-corrected visual acuity (BCVA), epithelial transparency, and impression cytology were also measured.

RESULTS

One year after surgery, successful cases showed a reduction (improvement) of all three parameters of corneal neovascularization [neovascular area (NA), VC, IA], while failed cases did not. NA decreased a mean of 32.31% (P=0.035), invasion area 29.37% (P=0.018) and VC 14.29% (P=0.072). BCVA improved in all eyes (mean follow-up, 76±21mo). Epithelial transparency improved significantly from 2.00±0.93 to 0.88±1.25 (P=0.014). Impression cytology showed that three cases failed after limbal epithelial stem cell therapy before 1y of follow-up.

CONCLUSION

This method of analyzing and monitoring surface vessels is useful for evaluating the epithelial status during follow-up, as successful cases showed a bigger reduction in corneal neovascularization parameters than failed cases. Using this method, successful cases could be differentiated from failed cases.

Antilymphangiogenic therapy to promote transplant survival and to reduce cancer metastasis: what can we learn from the eye?

The lymphatic vasculature is - amongst other tasks - essentially involved in inflammation, (auto)immunity, graft rejection and cancer metastasis. The eye is mainly devoid of lymphatic vessels except for its adnexa, the conjunctiva and the limbus. However, several pathologic conditions can result in the secondary ingrowth of lymphatic vessels into physiologically alymphatic parts of the eye such as the cornea or the inner eye. Therefore, the cornea has served as an excellent in vivo model system to study lymphangiogenesis, and findings from such studies have substantially contributed to the understanding of central principles of lymphangiogenesis also with relevance outside the eye. Grafting experiments at the cornea have been extensively used to analyze the role of lymphangiogenesis in transplant immunology. In this regard, we recently demonstrated the crucial role of lymphatic vessels in mediating corneal allograft rejection and could show that antilymphangiogenic therapy increases graft survival. In the field of cancer research, we recently detected tumor-associated lymphangiogenesis in the most common malignant tumors of the eye, such as conjunctival carcinoma and melanoma, and ciliochoroidal melanoma with extraocular extension. These neolymphatics correlate with an increased risk of local recurrence, metastasis and tumor related death, and may offer potential therapeutic targets for the treatment of these tumors. This review will focus on corneal and tumor-associated ocular lymphangiogenesis. First, we will describe common experimentally used corneal lymphangiogenesis models and will recapitulate recent findings regarding the involvement of lymphatic vessels in corneal diseases and transplant immunology. The second part of this article will summarize findings about the participation of tumor-associated lymphangiogenesis in ocular malignancies and their implications for the development of future therapeutic strategies.

Evaluation of fungal keratitis using a newly developed computer program, Optscore, for grading digital corneal photographs

PURPOSE

To validate computer software developed to assess digital corneal photographs of fungal keratitis in clinical research.

METHODS

A cornea specialist and five medical students (after training) graded on two occasions 100 corneal photographs of patients with fungal keratitis using Optscore software. Variables assessed were lesion area, location, degree of opacity, percentage of the ulcer lying within a central 4 mm circle of the cornea. Intraclass correlation coefficients (ICCs) were used to assess intragrader reliability, agreement of the students with the corneal specialist, and the reliability of the group mean of the student raters. The area determined using Optscore was compared to the area estimated from slit lamp and to visual acuity.

RESULTS

As a group, medical students achieved an ICC greater than 0.9 for five out of the seven assessed variables. Similar levels of consistency were found after analyzing the graders' individual results compared to the specialist. The area estimated using slit lamp examination was highly correlated with the mean area determined by Optscore, as was the logarithm of the minimum angle of resolution visual acuity at enrollment.

CONCLUSIONS

Non-expert graders using Optscore to assess digital photographs of fungal keratitis are self-consistent, agree with an expert grader both as a group and individually, and measurements of ulcer area obtained from Optscore are highly correlated with measurements of the same patients obtained on clinical examination. These observations support the validity of Optscore for assessing corneal pathology associated with fungal keratitis and make it a promising clinical research tool.

Efficacy of intralesional bevacizumab administration in primary pterygium: a quantitative analysis

OBJECTIVE

To analyze the regression of the pterygium tissue quantitatively after intralesional bevacizumab administration in patients with primary pterygium.

METHODS

Thirty-three eyes of 33 patients with primary pterygium who underwent intralesional bevacizumab (1.25 mg per 0.05 mL) administration were included in this prospective study. The ocular irritation, best-corrected visual acuity (BCVA), slit-lamp and funduscopic examinations, corneal astigmatism, the horizontal length, and the thickness of the pterygium were assessed before and after 2 months of treatment. To evaluate the corneal astigmatism and the thickness of the pterygium, the Pentacam comprehensive eye scanner (Pentacam CES; Oculus GmbH) was used.

RESULTS

After 2 months of bevacizumab administration, the average BCVA was improved (P=0.003). The average ocular irritation score, horizontal length, and the thickness of the pterygium were statistically significantly decreased (P<0.001, P<0.001, P<0.001, respectively).

CONCLUSION

After 2 months of intralesional bevacizumab administration, the average amount of decrease in the horizontal length and thickness of the pterygium was 0.6 mm and 37 μm, respectively. Intralesional bevacizumab administration is useful in the management of primary pterygium without having any local or systemic adverse effects; however, repeated administrations are needed to provide clinically more significant results.

Use of topical bevacizumab for conjunctival intraepithelial neoplasia

PURPOSE

To report our experience in the treatment of intraepithelial neoplasia of the conjunctiva using topical bevacizumab.

METHODS

Ten eyes of 10 patients with conjunctival neoplasia received 25 mg/mL bevacizumab topically. Changes in the lesions were documented weekly using digital photography. After topical treatment, excisional biopsy was performed.

RESULTS

The mean age of the patients was 60.5 ± 12 (33-77) years. The mean duration of topical treatment was 7.8 ± 1.3 (5-14) weeks. The size and vascularity of the tumors reduced weekly. All patients underwent excisional biopsy, cryotherapy, and amnion membrane transplantation. The histopathologic diagnosis of the lesions was carcinoma in situ. No recurrence was observed during the follow-up of patients for 6 months.

CONCLUSIONS

Topical bevacizumab is an effective treatment to reduce the tumor size before surgery and may be a good alternative for adjuvant therapy of conjunctival neoplasms.

Early effects of dexamethasone and anti-VEGF therapy in an inflammatory corneal neovascularization model

Inflammatory angiogenesis is the pathogenic mechanism of various sight-threatening eye diseases, among them corneal neovascularization. Current treatment options include steroids which have undesirable side effects, or anti-VEGF which has only limited efficacy. In an inflammatory environment, however, angiogenesis can be stimulated by numerous factors not directly targeted by anti-VEGF therapy. The aim of this study was to induce corneal inflammation leading to angiogenesis, and investigate the early, differential effects of steroid and anti-VEGF therapy at the cellular, tissue, and gene expression levels. Fifty-two Wistar rats received a single intrastromal corneal suture to induce a controlled inflammatory angiogenic response. Rats were subsequently treated with dexamethasone, rat specific anti-VEGF, or goat IgG (control), topically 4 times daily for 7 days. In vivo confocal microscopy of the cornea was performed longitudinally from 5 h up to 7 d to investigate morphology at the cellular and tissue-level. In vivo photographic vessel analysis and immunohistochemistry were also performed. RT-PCR for VEGF-A, FGF-2, IL-6, TNF-α, CXCL2, CCL2, CCL3 and DLL4 was performed at 24 h, and for VEGF-A, IL-6, TNF-α, FGF-2, CXCL2, CCL2, and CCL3 at 7 days. Early infiltration of CD11b + myeloid cells into the cornea at 5 h post-suture was delayed by both treatments relative to controls; however neither treatment was able to suppress accumulation of myeloid cells at day 2 or 7. Limbal vessel dilation was inhibited at 5 h by both treatments, but only dexamethasone showed sustained effect until day 2. Early macrophage recruitment was also suppressed by dexamethasone (but not by anti-VEGF) until day 2. Dexamethasone furthermore suppressed corneal neovascularization at day 7 by over 90%, whereas suppression by anti-VEGF was 14%. Despite differential suppression of vessel dilation, macrophage recruitment, and vascular invasion, anti-VEGF and dexamethasone both down-regulated VEGF-A and IL-6 expression at 24 h with sustained effect to 7 d. They also both down regulated FGF-2 and TNF-α at 24 h and CCL2 at 7 d. In conclusion, anti-angiogenic treatments influence early, pre-angiogenic tissue activity such as limbal vessel dilation, inflammatory cell infiltration of the stroma, and macrophage recruitment. Importantly, the differential effects of steroids and anti-VEGF treatment in suppressing neovascular growth could not be attributed to differential inhibition of several major angiogenic and inflammatory factors in the early pre-sprouting phase, including IL-6, VEGF-A, FGF-2, TNF-α, CCL2, CCL3, CXCL2, or DLL4.

Short-term effects of intravitreal bevacizumab on cornea and anterior chamber

PURPOSE

To determine the short-term effects of single-dose intravitreal bevacizumab injection on central corneal thickness (CCT), simulated keratometry (Sim K), anterior chamber depth (ACD), iridocorneal angle (ICA) and intraocular pressure (IOP) measurements.

DESIGN

Prospective, nonrandomized, interventional clinical trial.

MATERIALS AND METHODS

Forty-three eyes of 43 patients aged between 41 and 78 years (average 62 ± 13 years) received an intravitreal injection of 2.5 mg/0.1 mL bevacizumab. Patients who had not undergone additional intravitreal anti-vascular endothelial growth factor therapy within 6 months were included in the study. CCT, Sim K, ACD and ICA measurements were obtained with Sirius Topographer. IOP measurements were taken after topographic measurements with Goldmann applanation tonometer. The CCT, ACD, ICA and IOP measurements were taken before and after 3rd, 15th days and 1st month of intravitreal bevacizumab injection.

RESULTS

Pre- and postinjection of 3rd, 15th days and 1st month CCT (p = 0.999), Sim K (p = 0.746), ACD (p = 0.996), ICA (p = 0.632) and IOP (p = 0.707) measurements were not statistically different. Mean CCT (p = 1.000), Sim K (0.972), ACD (p = 0.998), ICA (0.667) and IOP (0.951) values were similar before and after 3rd day of bevacizumab injection. Mean CCT (p = 0.999), Sim K (p = 0.994), ACD (p = 1.000), ICA (p = 0.999) and IOP (p = 1.000) measurements were also similar before and after 15th day of injection. Preinjection and 1st month of postinjection CCT (p = 0.999), Sim K (p = 0.932), ACD (p = 0.998), ICA (p = 1.000) and IOP (p = 0.741) measurements did not change significantly.

CONCLUSIONS

Single-dose intravitreal bevacizumab injection does not affect CCT, Sim K, ACD, ICA and IOP in short-term period.

Topical bevacizumab for neovascular glaucoma: a pilot study

BACKGROUND/AIMS

Bevacizumab (Avastin), an anti-vascular endothelial growth factor drug, has been successfully used in recent years to treat ocular pathologies, mostly by intravitreal administration. The aim of this study was to investigate the safety and efficacy of topically applied bevacizumab for the treatment of neovascular glaucoma (NVG).

METHODS

Patients with NVG were treated with topical bevacizumab (25 mg/ml) 4 times daily during 2 weeks. The following parameters were evaluated at baseline and on days 3, 7 and 14: visual acuity, slit-lamp examination, intraocular pressure (IOP), heart rate and systemic blood pressure. Iris neovascularization was documented using slit-lamp color photos at baseline and on day 14.

RESULTS

Eight eyes of 8 patients with NVG were evaluated. After the 2-week treatment, mean IOP was lowered from 34.9 mm Hg (SD 12.8) at baseline to 28.8 mm Hg (SD 9.9) on day 14, representing a mean reduction of 6.1 mm Hg (17.5%). Three patients had clinical regression of their iris neovascularization. Ocular adverse events were transient and included mild upper eyelid swelling, mild exacerbation of superficial punctate keratitis and mild corneal epithelial bullae in an already edematous cornea. There were no serious systemic adverse events.

CONCLUSIONS

Topical application of bevacizumab may lower IOP and result in regression of neovascularization in patients with NVG.

Subconjunctival bevacizumab injection for ocular surface squamous neoplasia

PURPOSE

To determine the efficacy and safety of perilesional/subconjunctival bevacizumab injections in the management of ocular surface squamous neoplasia (OSSN).

METHODS

Ten eyes of 10 patients with an OSSN diagnosis confirmed by impression cytology received 2 perilesional/subconjunctival injections of bevacizumab at a 2-week interval. Patients were evaluated for 3 months, during which time, changes in the lesions were documented using digital photography. After this period, excisional biopsy of the remaining tumor and cryotherapy of the conjunctival borders were performed if deemed necessary.

RESULTS

The mean age of the patients was 65 ± 12 years (± SD). All of the tumors were nasal in origin and had varying degrees of vascularization. The mean lesion area before treatment was 16 ± 6.9 mm2. Two weeks after the first injection, the mean reduction observed in the tumor area was 25% ± 5.65% and ranged from 17% to 33% (P = 0.001). Two weeks after the second injection, the mean tumor area was further decreased (42% ± 33%, ranging from 15% to 100%, P = 0.049). Corneal extension of the tumor was not affected significantly in 8 of the eyes with concomitant conjunctival and corneal involvement. Complete disappearance of the tumor was demonstrated by impression cytology and occurred in 2 cases involving lesions clinically confined to the conjunctiva. No systemic or ocular side effects occurred during the study period.

CONCLUSIONS

Perilesional/subconjunctival injections of bevacizumab decrease the size and vascularity of OSSN and may be curative in lesions limited to the conjunctiva. However, this treatment has no significant effect on the corneal extension of OSSN.

Topical ranibizumab as a treatment of corneal neovascularization

PURPOSE

To examine the effect of topical ranibizumab on clinically stable corneal neovascularization (NV).

METHODS

This was a prospective, open-label, monocentric, uncontrolled noncomparative study. Ten eyes of 9 patients with corneal NV received topical ranibizumab (1%) 4 times a day for 3 weeks with a follow-up period of 16 weeks. The main corneal NV outcome measures were: neovascular area, the area occupied by the corneal neovessels; vessel caliber (VC), the mean diameter of the corneal neovessels; and invasion area (IA), the fraction of the total cornea area covered by the vessels. This study was conducted at the Massachusetts Eye and Ear Infirmary, Boston, MA.

RESULTS

Statistically significant decreases in neovascular area (55.3%, P < 0.001), which lasted through 16 weeks, and VC (59%, P < 0.001), which continued to improve up to week 16, were observed after treatment. No significant decrease was observed in IA (12.3%, P = 0.49). There was no statistically significant change in visual acuity or intraocular pressure. No adverse events ascribed to the treatment were noted.

CONCLUSIONS

Topical application of ranibizumab is effective in reducing the severity of corneal NV in the context of established corneal NV, mostly through decrease in VC rather than IA.

High-dose topical bevacizumab for corneal neovascularization

BACKGROUND/AIMS

Bevacizumab (Avastin), an anti-vascular endothelial growth factor drug, has been successfully used in the recent years to treat ocular pathologies, mostly by intravitreal administration. The aim of the current study was to assess the off-label topical use of high-dose bevacizumab for the treatment of corneal neovascularization.

METHODS

Seventeen eyes of 17 patients with corneal neovascularization secondary to various pathologies were included. The patients were treated with topical bevacizumab (25 mg/ml) 4 times daily for 2 weeks. The following parameters were evaluated at baseline and on days 3, 7 and 14: visual acuity, slit-lamp examination, intraocular pressure, heart rate and blood pressure. Color photos were obtained at baseline and on day 14.

RESULTS

Eleven eyes (65%) demonstrated regression of corneal neovascularization and/or clearing of corneal opacification. Adverse ocular events were mild and transient, and included eyelid swelling/chalazion and superficial punctate keratitis.

CONCLUSION

Treatment with high-dose topical bevacizumab (25 mg/ml) was effective for corneal neovascularization in nearly two thirds of the eyes treated. Adverse ocular side effects were mild and transient.

The effect of subconjunctival ranibizumab on corneal and anterior segment neovascularization: study on an animal model

PURPOSE

To evaluate the effect of subconjunctival anti-vascular endothelial growth factor (VEGF) ranibizumab on corneal and anterior segment neovascularization.

METHODS

In this experimental study and laboratory investigation, chemical cauterization was utilized to induce corneal neovascularization in 16 rabbits randomly divided in 2 equal groups. Cauterized eyes were either treated with 0.1 mL (1 mg) of subconjunctival ranibizumab or administered a sham injection. A third group of 4 rabbits served as control for side effects after ranibizumab administration. All animals were monitored daily for 14 days and the extent of corneal scarring and neovascularization was measured on days 1, 7, and 14. After enucleation, ocular tissues were separated under a surgical microscope and VEGF levels were measured with ELISA. Statistical analysis was performed to compare the extent of corneal neovascularization and VEGF levels between treated and untreated eyes.

RESULTS

Subconjunctival ranibizumab inhibited corneal neovascularization significantly both in the first and the second week compared to untreated controls (p = 0.006 and p = 0.001, respectively). The VEGF levels were significantly lower in all anterior segment tissues like the cornea, iris, aqueous humor, and conjunctiva of the treated eyes (p<0.01). The reduction of VEGF levels ranged from 19% to 73% in different ocular tissues. Corneal scarring was not significantly affected by anti-VEGF treatment (p = 0.7). No side effects were noticed.

CONCLUSIONS

Early subconjunctival administration of ranibizumab may successfully inhibit alkali-induced corneal neovascularization in an animal model. Subconjunctival ranibizumab reduces VEGF levels significantly not only in the cornea and the bulbar conjunctiva but also in the aqueous humor and the iris.

Pharmacokinetics of bevacizumab after topical and intravitreal administration in human eyes

Background

Topical bevacizumab is a potential treatment modality for corneal neovascularization, and several recent studies have demonstrated its efficacy. No previous study of the pharmacokinetics of topical bevacizumab has been performed in human eyes. The purpose of this study is to investigate the pharmacokinetics of topical administration of bevacizumab in human eyes, and also to compare the pharmacokinetics of intravitreal bevacizumab injections with previously reported data.

Methods

Twenty-two (22 eyes) were included in this study, and divided into four groups: eight patients received topical bevacizumab and aqueous samples were obtained 1 hour later during cataract extraction surgery (group 1), eight patients received topical bevacizumab and vitreous samples were obtained 1 day later during pars-plana vitrectomy (PPV) (group 2), three patients received intravitreal bevacizumab and vitreous samples were obtained during PPV (group 3). Vitreous samples from three patients who received no bevacizumab served as controls (group 4). All samples underwent enzyme-linked immunosorbent assay to detect bevacizumab.

Results

No bevacizumab was detected in the aqueous or vitreous of any topically treated eyes. The mean vitreal half-life for intravitreally injected bevacizumab was 4.9 days in four non-vitrectomized eyes and 0.66 days in one previously vitrectomized eye.

Conclusions

Topically administered bevacizumab does not penetrate the cornea into the anterior chamber and vitreous cavity, indicating that topical use for treating corneal neovascularization has minimal risk of intraocular penetration and adverse events related to intraocular vascular endothelial growth factor inhibition. The half-life following intravitreal bevacizumab injection measured in this study is comparable to that of previous reports, and includes the first demonstration of a significantly reduced half-life following intravitreal injection in a previously vitrectomized eye.

Inhibitory effects of topical cyclosporine A 0.05% on immune-mediated corneal neovascularization in rabbits

BACKGROUND

We aimed to study the inhibitory effects of topical cyclosporine A (CsA) 0.05% on immune-mediated corneal neovascularization, and to compare its efficacy with those of dexamethasone 0.1% and bevacizumab 0.5%.

METHODS

Immune-mediated corneal neovascularization was created in 36 right eyes of 36 rabbits. The rabbits were then randomized into four groups. Group I received CsA 0.05%, Group II received dexamethasone 0.1%, Group III received bevacizumab 0.5%, and Group IV received isotonic saline twice a day for 14 days. The corneal surface covered with neovascular vessels was measured on the photographs. The rabbits were then sacrificed and the corneas excised. Paraffin-embedded sections were stained with hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay.

RESULTS

The means of percent area of corneal neovascularization in Group I, II, III, and IV were 24.4%, 5.9%, 37.1%, and 44.1%, respectively. The inhibitory effect of CsA 0.05% was found to be better than the effect found in the bevacizumab 0.5% and control groups (p = 0.03 and p = 0.02, respectively). CsA 0.05% was found to have significantly lesser inhibitory effects on corneal neovascularization than dexamethasone 0.1% (p < 0.001). Apoptotic cell density was higher in Group III and Group IV than in Group I and Group II. There was no difference between Group I and Group II in terms of apoptotic cell density (p = 0.7).

CONCLUSIONS

Topical CsA 0.05% was shown to have an inhibitory effect on immune-mediated corneal neovascularization in rabbits.

The effect of topical doxycycline on corneal neovascularization

PURPOSE

To examine the effect of topical doxycycline on human corneal neovascularization (CONV).

MATERIALS AND METHODS

Six eyes of six patients with CONV received topical 1% doxycycline four times per day for three weeks and monitored for a total of one year. Ophthalmic evaluations included visual acuity, tonometry, slit-lamp examination, conjunctival swabs, quantification of CONV and photography.

RESULTS

CONV either disappeared or was attenuated, shortened and less dense in five of six patients. There were no adverse effects.

CONCLUSION

Topical doxycycline was effective in reducing CONV and healing of the ocular surface.

[Imaging and quantification of corneal neovascularization]

Corneal neovascularization is defined as the invasion of vessels into the normally avascular clear corneal stroma, secondary to acute or chronic tissue injury. In addition to decreasing visual acuity, vascularity introduces circulating immune cells, reducing corneal immune privilege and the graft survival of subsequent keratoplasty. Thus, reducing neovascularization has become a recent therapeutic target in order to increase the success of corneal transplantation. Comparing the effects of antiangiogenic drugs assumes that we are able to quantify corneal neovascularization before and after treatment. In the first part of this literature review, we present the various methods to document neovessels (color photos, fluorescein and indocyanine green anterior segment angiography, in vivo confocal microscopy). Next, we report methods to classify and quantify corneal neovascularization.

Randomized, controlled trial of conjunctival autografting combined with subconjunctival bevacizumab for primary pterygium treatment: 1-year follow-up

BACKGROUND

To investigate the efficacy and safety of subconjunctival bevacizumab application as an adjuvant therapy for primary pterygium.

DESIGN

This study was a clinical randomized trial performed at the Institute of Ophthalmology 'Conde de Valenciana'.

PARTICIPANTS

Forty-nine patients with primary pterygium were enrolled in the study.

METHODS

Each primary pterygium patient was randomized after pterygium excision and a conjunctival autograft to receive either a single 2.5 mg/0.1 mL dose of subconjunctival bevacizumab immediately after surgery (group 1); a double 2.5 mg/0.1 mL injection of subconjunctival bevacizumab, one immediately after surgery and the second 15 days after surgery (group 2); or no injection (group 3).

MAIN OUTCOME MEASURES

Autoconjunctival graft presence or absence of ischaemia, necrosis, infection or detachment; surgical bed appearance; and pterygium recurrence at 1-year follow-up period were determined.

RESULTS

Forty-nine eyes of 49 patients were included. Sixteen patients were assigned to group 1, 17 to group 2 and 16 to group 3. Patients from groups 1 and 2 showed conjunctival autograft ischaemia at 24 h postoperative (37.5% and 58.8%, respectively, P > 0.05), which disappeared by the first postoperative month. No significant difference in the main outcome measures was found among single versus double-dose of subconjunctival bevacizumab injection patients. At the end of the study, pterygium recurrences were observed only in group 3 (P < 0.04).

CONCLUSIONS

A single 2.5 mg/mL subconjunctival bevacizumab injection in conjunction with primary pterygium surgery accomplishing a conjunctival autograft procedure is safe and well tolerated, and is capable of preventing pterygium recurrences when compared with a control group.

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.

A case of recipient bed melt and wound dehiscence after penetrating keratoplasty and subconjunctival injection of bevacizumab

We describe a case of recipient bed melt and wound dehiscence after uneventful penetrating keratoplasty and subconjunctival injection of bevacizumab. Three weeks postoperatively, the patient presented with limbal ischemia, recipient bed melt, and wound dehiscence corresponding to the area of bevacizumab injection. The melt was managed by application of cyanoacrylate glue along with bandage contact lens. Although the graft survived, there was a problem in re-epithelization. This case highlights the need for further studies to elucidate the therapeutic dose, side effects, and correct timing of using bevacizumab with respect to corneal transplant surgery.

H-RN, a peptide derived from hepatocyte growth factor, inhibits corneal neovascularization by inducing endothelial apoptosis and arresting the cell cycle

BACKGROUND

The goal of this study was to investigate the anti-angiogenic activity of a novel peptide H-RN, derived from the hepatocyte growth factor kringle 1 domain (HGF K1), in a mouse model of corneal neovascularization. The anti-angiogenic effect of H-RN on vascular endothelial growth factor (VEGF)-stimulated cell proliferation, cell migration and endothelial cell tube formation was assessed in vitro using Human Umbilical Vein Endothelial Cells (HUVECs) and in vivo using a mouse cornea micropocket assay. Apoptosis and cell cycle arrest were assessed by flow cytometry. A scrambled peptide was used as a negative control.

RESULTS

H-RN effectively inhibited VEGF-stimulated HUVEC proliferation, migration and tube formation on Matrigel, while a scrambled peptide exerted no effect. In the mouse model of corneal angiogenesis, VEGF-stimulated angiogenesis was significantly inhibited by H-RN compared to a scrambled peptide that had no such activity. VEGF protected HUVECs from apoptosis, while H-RN inhibited this protective effect of VEGF. VEGF significantly increased the proportion of cells in the S phase compared to control treated cells (p<0.05). Treatment with H-RN (1.5 mM) induced the accumulation of cells in G0/G1 phase, while the proportion of cells in the S phase and G2/M phase decreased significantly compared to control group (p<0.05).

CONCLUSIONS

H-RN has anti-angiogenic activity in HUVECs and in a mouse model of VEGF-induced corneal neovascularization. The anti-angiogenic activity of H-RN was related to apoptosis and cell cycle arrest, indicating a potential strategy for anti-angiogenic treatment in the cornea.