Efficiency and safety of subconjunctival injection of anti-VEGF agent - bevacizumab - in treating dry eye

Evidence of air pollution-related ocular signs and altered inflammatory cytokine profile of the ocular surface in Beijing

We evaluated how different degrees of air pollution affect the ocular surface of a cohort of human subjects in Beijing by correlating in-patient test outcomes with tear cytokines. A cross-sectional study involving 221 volunteers was carried out in different districts of Beijing. Air pollution indices were recorded for 7 d (including the visit day). The indices recorded were the air quality index (AQI), which is a dimensionless measure that quantitatively describes the state of air quality, concentrations of particulate matter smaller than 2.5 μm (PM2.5) and 10 μm (PM10), sulfur dioxide (SO₂), ozone (O₃), and nitrogen dioxide (NO₂). The Ocular Symptom Disease Index (OSDI) questionnaire provided. Subsequently, subjects underwent slit-lamp examination, which included meibomian gland examination, conjunctival congestion score, conjunctivochalasis grade, tear meniscus height (TMH), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test, and conjunctival impression cytology. The concentrations of vascular endothelial growth factor (VEGF), interleukins (IL)-1β, IL-6 and IL-8 in tears were measured by microsphere-based immunoassay analysis. According to the value of the AQI, participants are divided into a slightly polluted (SP) group (n = 103) which the AQI value is less than or equal to 100 and a heavily polluted (HP) group (n = 118) whose AQI value is more than 100. Air pollution is related to ocular discomfort based on tear cytokine concentrations. PM2.5, PM10 and NO₂ were positively correlated with OSDI, MG expressibility, meibum score, meiboscore, conjunctival congestion score, Schirmer I test value, TMH, goblet-cell density, concentrations of IL-6, and VEGF were negatively correlated with TBUT. PM2.5 and PM10 appear to be the major risk factors to the ocular surface, with NO₂ being another important risk factor based on this study. The symptoms and signs of eye discomfort in the SP group were significantly less severe than those in the HP group, and tear cytokine concentrations (IL-6 and VEGF) were lower. Air pollution degrees were significantly correlated with tear cytokine concentrations, indicating an alteration of cytokine balance at the ocular surface under different degrees of air pollution.

Bevacizumab Eye Drops Vs. Intra-meibomian Gland Injection of Bevacizumab for Meibomian Gland Dysfunction-Associated Posterior Blepharitis

Aims

This study aimed to evaluate the efficacy and safety of bevacizumab eye drops compared with those of an intra-meibomian gland (MG) injection of bevacizumab when performed in conjunction with standard lid hygiene in patients with meibomian gland dysfunction (MGD)-associated posterior blepharitis.

Methods

This prospective, open-label, observer-blinded randomized controlled trial included 60 eyes of 30 patients with MGD-associated posterior blepharitis who exhibited lid margin telangiectasia, treated at the Chula Refractive Surgery Center of King Chulalongkorn Memorial Hospital. Patients were randomized to receive lid hygiene plus 0.05% bevacizumab eye drops or a single intra-MG injection of 2.5% bevacizumab. All patients were instructed to perform routine lid hygiene care as demonstrated in an instructional video. Primary outcomes included telangiectasia grading and the lid margin neovascularized area (LMNA). Secondary outcomes included the Ocular Surface Disease Index (OSDI) score, corneal staining, meibum quality, meiboscore, conjunctival redness, fluorescein break-up time (FBUT), lipid layer thickness, treatment compliance, and adverse events. All parameters were evaluated before and 3 months after treatment.

Results

After treatment, there were no significant differences in telangiectasia grade and LMNA between groups (mean difference, −0.14, 95% CI −0.42 to 0.15, p = 0.338, −0.1, 95% CI −1.1 to 0.8, p = 0.761, respectively); however, the injection group exhibited significant improvements in both telangiectasia grade and LMNA, while, in the eye drop group, only telangiectasia grade showed a significant improvement relative to baseline. The injection group also exhibited significant improvements in corneal staining (mean difference, −0.78, 95% CI −1.29 to −0.27, p = 0.003), meiboscores (mean difference, −0.37, 95% CI −0.52 to −0.21, p <0.001), and FBUT (mean difference, 1.25, 95% CI 0.21–2.29, p = 0.019) compared to the eye drop group. OSDI scores, corneal staining, meibum quality, meiboscores, and conjunctival redness significantly improved relative to baseline in both groups. No local and systemic adverse event was observed at month 3 in both groups.

Conclusion

When performed with regular lid hygiene, intra-MG injection and topical application of bevacizumab are safe and effective for improving lid margin telangiectasia and the signs and symptoms of MGD-associated posterior blepharitis. This therapy may represent an alternative or adjunctive treatment for patients with MGD-associated posterior blepharitis.

Efficacy of topical bevacizumab 0.05% eye drops in dry eye disease: A double-masked, randomized trial

The objective of this double-masked, placebo-controlled, randomized trial was to assess the efficacy and safety of bevacizumab 0.05% eye drops in dry eye patients. This study included Dry Eye Workshop Study (DEWS) Grade 3–4 dry eye participants (n = 31) whose tear break-up time (TBUT) was ≤5 seconds(s). Participants were randomized to undergo treatment with either bevacizumab 0.05% eye drops (n = 19) or placebo (n = 12). The primary outcome was TBUT, and the proportion of responders (increase of ≥3s in TBUT at week 12), ocular surface disease index (OSDI) score, Schirmer test, and Oxford scheme grade were secondary outcomes. All outcomes were measured at 1-, 4- and 12 weeks. TBUT in bevacizumab group differed significantly from TBUT in placebo group within 12 weeks (P = 0.001). Moreover, the improvement of TBUT in bevacizumab group versus placebo group at 4- and 12 weeks differed significantly from that difference at baseline (P = 0.002 and P = 0.003, respectively). The proportion of participants achieving increase of 3 seconds or more of TBUT at week 12 in the bevacizumab group was significantly greater than that in the placebo group (P = 0.02). Oxford scheme grade at 1-, 4- and 12 weeks differed significantly from the values at baseline in bevacizumab group (P = 0.001, P = 0.01, and P = 0.03, respectively). OSDI scores at 1-, 4- and 12-week follow-ups were significantly lower than that at baseline in bevacizumab group (P<0.001 at each follow-up). Schirmer test were not significantly different within or between groups (the lowest P = 0.92). No adverse events occurred in this study. Patients treated with bevacizumab 0.05% eye drops showed significant improvement in tear film stability, corneal staining and symptoms.

Sustained-release voriconazole-thermogel for subconjunctival injection in horses: ocular toxicity and in-vivo studies

Background

Keratomycosis is a relatively common, sight threatening condition in horses, where treatment is often prolonged and costly. Subconjunctival (SCo) injections offer less resistance to drug diffusion than the topical route, resulting in better penetration to the ocular anterior segment. Voriconazole, a second generation triazole antifungal, is effective against common fungal organisms causing keratomycosis. If combined with a thermogel biomaterial, voriconazole can be easily injected in the SCo space to provide sustained drug release. The purpose of this study was to evaluate the drug concentrations in the anterior segment and clinical effects after SCo injections of voriconazole-containing thermogel: poly (DL-lactide-co-glycolide-b-ethylene glycol-b-DL-lactide-co-glycolide) (PLGA-PEG-PLGA) in healthy equine eyes.

Results

Voriconazole aqueous humor (AH) and tear concentrations were compared between 6 horses, receiving 1% voriconazole applied topically (0.2 mL, q4h) (Vori-Top) or 1.7% voriconazole-thermogel (0.3 mL) injected SCo (Vori-Gel). For the Vori-Gel group, voriconazole concentrations were measured in AH and tears at day 2 and then weekly for 23 days, and at day 2 only for the Vori-Top group. Ocular inflammation was assessed weekly (Vori-Gel) using the modified Hackett-McDonald scoring system. Ocular tissue concentrations of voriconazole following SCo 1.7% voriconazole-thermogel (0.3 mL) injections were evaluated post euthanasia in 6 additional horses at 3 different time points. Three horses received bilateral injections at 2 h (n = 3, right eye (OD)) and 48 h (n = 3, left eye (OS)) prior to euthanasia, and 3 horses were injected unilaterally (OS), 7 days prior to euthanasia. Voriconazole-thermogel was easily injected and well tolerated in all cases, with no major adverse effects. On day 2, drug concentrations in tears were higher in the Vori-Top, but not statistically different from Vori-Gel groups. For the Vori-Gel group, voriconazole was non-quantifiable in the AH at any time point. Total voriconazole concentrations in the cornea were above 0.5 μg/g (the target minimum inhibitory concentration (MIC) for Aspergillus sp.) for up to 48 h; however, concentrations were below this MIC at 7 days post treatment.

Conclusions

Voriconazole-thermogel was easily and safely administered to horses, and provided 48 h of sustained release of voriconazole into the cornea. This drug delivery system warrants further clinical evaluation.

The Key Role of VEGF in the Cross Talk between Pterygium and Dry Eye and Its Clinical Significance

PURPOSE

To examine whether dry eye severity is a risk factor for pterygium activity and whether vascular endothelial growth factor (VEGF) is crucial in the cross talk between pterygium and dry eye.

METHODS

A total of 103 patients with primary pterygium (Pteg) were included in the study group; they were divided into 2 groups according to the complication of dry eye (DE) (Pteg + DE group, Pteg - DE group). Further, 60 patients with just dry eye (DE group) and 60 normal individuals (normal) were included as 2 control groups. DE severity and pterygium activity were measured, and unstimulated tear samples and pterygium tissues were collected for cytokine detection.

RESULTS

(1) Tear detection: VEGF expression increased in the Pteg + DE group compared to the Pteg - DE, DE, and normal control groups; VEGF was especially increased in the active Pteg + DE group. VEGF concentration was positively correlated with pterygium activity. (2) Tissue detection: the mRNA expression of VEGF was upregulated in the active pterygium group.

CONCLUSIONS

Inflammation played an important role in the development of dry eye and pterygium. VEGF was the core molecule in the cross talk, which might explain the high incidence of the coexistence of these 2 diseases.

Efficacy of intra-meibomian gland injection of the anti-VEGF agent bevacizumab for the treatment of meibomian gland dysfunction with lid-margin vascularity

Purpose

To investigate the efficacy of a novel treatment - intra-meibomian gland (MG) injection of the anti-VEGF agent bevacizumab - for MG dysfunction (MGD) with eyelid-margin vascularity.

Methods

A total of 26 eyes from 13 patients diagnosed with MGD and eyelid-margin vascularity were included in our study. Patients received intra-meibomian gland injections of bevacizumab (150 μL, 2.5 mg/0.1 mL) at multiple sites with a 29 G needle where telangiectasia was severe. The Ocular Surface Disease Index (OSDI), tear film, tear-breakup time (TBUT), eyelid-margin features, MG features, conjunctiva, and corneal staining were assessed at 1 day before injection and 1 week, 1 month, and 3 months after injection. Blood pressure, best-corrected visual acuity, intraocular pressure, and slit lamp examinations were performed to assure the safety of patients at 1 day before and 1 day, 1 week, 1 month, and 3 months after injection.

Results

Lid-margin vascularity, conjunctival injection, expressed secretion quality, expressivity of the MG, TBUT, corneal staining, and OSDI were significantly improved 1 week, 1 month, and 3 months after injection compared to baseline values. Lid-margin vascularity, conjunctival injection, meibomian gland expressivity, TBUT, and OSDI continued to improve; the greatest improvements were observed at 1 month and sustained for 3 months. Spearman's correlation analysis indicated that age and sex significantly influenced TBUT improvement. Females and older patients tended to have shorter baseline TBUT that followed a different trend from that of males and younger patients during postinjection visits, revealed by subgroup analysis. No local or systemic side effects were observed at follow-up visits.

Conclusion

This study is the first to explore a novel therapy for MGD - intra-MG injection of the anti-VEGF agent bevacizumab - and it demonstrates that the treatment is effective and safe in eliminating eyelid-margin vascularity, improving MG function and relieving clinical signs and symptoms of MGD.

Effect of trapping vascular endothelial growth factor-A in a murine model of dry eye with inflammatory neovascularization

AIM

To evaluate whether trapping vascular endothelial growth factor A (VEGF-A) would suppress angiogenesis and inflammation in dry eye corneas in a murine corneal suture model.

METHODS

We established two groups of animals, one with non-dry eyes and the other with induced dry eyes. In both groups, a corneal suture model was used to induce inflammation and neovascularization. Each of two groups was again divided into three subgroups according to the treatment; subgroup I (aflibercept), subgroup II (dexamethasone) and subgroup III (phosphate buffered saline, PBS). Corneas were harvested and immunohistochemical staining was performed to compare the extents of neovascularization and CD11b+ cell infiltration. Real-time polymerase chain reaction was performed to quantify the expression of inflammatory cytokines and VEGF-A in the corneas.

RESULTS

Trapping VEGF-A with aflibercept resulted in significantly decreased angiogenesis and inflammation compared with the dexamethasone and PBS treatments in the dry eye corneas (all P<0.05), but with no such effects in non-dry eyes. The anti-inflammatory and anti-angiogenic effects of VEGF-A trapping were stronger than those of dexamethasone in both dry eye and non-dry eye corneas (all P<0.05). The levels of RNA expression of VEGF-A, TNF-alpha, and IL-6 in the aflibercept subgroup were significantly decreased compared with those in the PBS subgroup in the dry eye group.

CONCLUSION

Compared with non-dry eye corneas, dry eye corneas have greater amounts of inflammation and neovascularization and also have a more robust response to anti-inflammatory and anti-angiogenic agents after ocular surface surgery. Trapping VEGF-A is effective in decreasing both angiogenesis and inflammation in dry eye corneas after ocular surface surgery.

Gene Delivery by Subconjunctival Injection of Adenovirus in Rats: A Study of Local Distribution, Transgene Duration and Safety

Subconjunctival injection is a minimally invasive route for gene delivery to ocular tissues, but has traditionally been limited to use in the cornea. The accurate ocular distribution of virus has not, however, been previously investigated. Adenovirus is an attractive gene vector as it can deliver large genes and allow for short-term gene expression, but how safe it is when delivered via subconjunctival injection remains to be established. We have characterized the bio-distribution and safety of subconjunctivally administered adenovirus in Brown Norway rats. The bio-distribution and transgene duration of adenovirus carrying luciferase gene (Ad-Luci) at various time intervals were evaluated via bioluminescence imaging after subconjunctival injection. Adenovirus carrying a reporter gene, β-galactosidase (Ad-LacZ) or hrGFP (Ad-hrGFP) was administered subconjunctivally and the viral distribution in various ocular tissues was assessed by histological analysis and quantitative PCR (qPCR). Hepatic damage was assessed by biochemical and immunohistological analysis with TUNEL stain. Systemic immunogenicity was assessed by measuring serum level of TNF-α via ELISA, 2 hours and 14 days after administration of adenovirus. Retinal function was examined by electroretinography. Subconjunctival injection of Ad-Luci induced luciferase expression in the injected eyes within 24 hours, for at least 64 days. Histological analysis showed adenovirus distributed across anterior and posterior ocular tissues. qPCR demonstrated different amounts of adenovirus in different ocular tissues, with the highest amounts closest to the injection site Unlike the intravenous route, subconjunctivally delivered adenovirus did not elicit any detectable hepatic injury or systemic immunogenicity. Retinal function was unaffected by adenovirus irrespective of administration route. In conclusion, an adenoviral vector administered subconjunctivally can infiltrate into different ocular tissues and lead to short-term ocular transgene expression, without causing hepatic injury and immune activation. Therefore, subconjunctivally administered adenovirus may be a promising gene delivery approach for managing anterior and posterior segment eye diseases requiring short-term therapy.