A Mouse Model for Corneal Neovascularization by Alkali Burn
June 30th, 2023
This protocol focuses on alkali burn-induced corneal neovascularization in mice. The method generates a reproducible and controllable corneal disease model to study pathological angiogenesis and the associated molecular mechanisms and to test new pharmacological agents to prevent corneal neovascularization.
We are trying to develop a highly reproducible model for inducing corneal neovascularization and to identify the most relevant histological and immunostaining methods to monitor therapies to prevent and reduce neovascularization. The drawbacks of corneal alkali burn models are difficulties in controlling the area and severity of alkali burn, variation of corneal neovascularization, and unintentional burn of edges and tissues due to excess alkali solution. Corneal neovascularization is a sight-threatening condition.
The pathogenesis of this condition is poorly understood. This model will be used to gain new insight into the condition and to identify relevant therapeutic targets. Compared to the corneal pocket angiogenesis model, alkali burn models are relatively straightforward to create and can also be used to study corneal inflammation, fibrosis, and epithelial proliferation.
These models are also more closely related to clinical chemical burns than corneal suture models of angiogenesis. We will use alkali burn cornea as a disease model to investigate novel anti-angiogenic therapy to treat cornea neovascularization and opacity. To begin, inject meloxicam subcutaneously into the six to eight weeks old C57 Black 6J male mouse 30 minutes before the procedure for pain relief.
After anesthetizing the mouse, pinch the toes and confirm the absence of the reflex. Apply one drop of 0.5%proparacaine on the corneal surface of one and a drop of artificial tears on the other eye. Next, using a two-millimeter biopsy punch, punch out Whatman filter paper discs.
Add two microliters of one normal sodium hydroxide to a clean Petri dish, and place the filter paper disc on the sodium hydroxide drop, allowing it to soak up for 15 seconds. Using forceps, pick up the filter paper, and apply it to the proparacaine-treated eye at the center of the cornea for 30 seconds. Wash the eye by flushing with 20 milliliters of sterile saline in a syringe.
Wipe the excess saline gently from the eyes and the surrounding area using disposable soft wipes. Place the mouse in a recovery cage on a warm heating pad until ambulatory. On day 10 after the burn, capture OCT images of the anterior segment of the eyes as a volume scan using HRA+OCT mode with a 30 degree field of view and 100%IR intensity.
The corneal neovascularization sprouted from the limbus vessels toward the corneal center in the alkali-burned mouse eye, but not in the healthy eye. The alkali burn group demonstrated significantly elevated neovascularization and opacity scores compared to the control group. Immunostaining of corneas for blood and lymph vessels showed significantly higher densities of blood vessels and lymph vessels after 10 days in the burn group compared to the control group.
The thickness of the cornea imaged and quantified using OCT was significantly higher in the burn group.
Overview
This study focuses on developing a reproducible model of corneal neovascularization induced by alkali burns in mice. The model aims to elucidate the mechanisms underlying pathological angiogenesis and evaluate potential pharmacological interventions to mitigate corneal neovascularization.
Key Study Components
Research Area
- Pathological angiogenesis
- Corneal disorders
- Pharmacological therapy evaluation
Background
- Corneal neovascularization is a significant threat to vision.
- The current understanding of its pathogenesis is limited.
- Existing models have issues with reproducibility and control.
Methods Used
- Alkali burn model using sodium hydroxide
- C57 Black 6J male mice
- Histological and immunostaining techniques for assessment
Main Results
- Increased neovascularization and opacity in alkali-burned corneas compared to controls.
- Higher densities of blood and lymph vessels in the burn group.
- Significant differences in corneal thickness measured by OCT.
Conclusions
- This model facilitates the investigation of novel anti-angiogenic therapies.
- It provides insights relevant to clinical chemical burns and corneal healing.
Frequently Asked Questions
Executive Industry Relevance
Robust preclinical models for corneal neovascularization are essential for de-risking anti-angiogenic drug discovery and clarifying disease mechanisms. The alkali burn mouse model provides a reproducible, quantifiable system for evaluating therapeutic interventions and understanding pathological angiogenesis in an accessible, avascular tissue. This model supports translational continuity from early discovery through preclinical validation, directly impacting portfolio prioritization for ocular and angiogenesis-targeted programs.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of angiogenic pathways and identification of therapeutic targets in a controlled in vivo context.
- Supports biological de-risking by modeling clinically relevant chemical injury and its sequelae.
- Facilitates predictive confidence in target engagement and mechanism-of-action studies for anti-angiogenic agents.
Screening & Assay Development
- Provides a standardized, reproducible platform for evaluating candidate compounds and biologics targeting neovascularization.
- Delivers quantitative outputs via immunostaining (CD31, LYVE-1) and OCT imaging for objective assessment.
- Enables assay scalability and cross-study comparability through defined injury parameters and readouts.
Translational & Preclinical Research
- Aligns with disease-relevant injury mechanisms observed in clinical chemical burns.
- Supports continuity from mechanistic discovery to preclinical efficacy and biomarker validation.
- Informs risk-adjusted advancement decisions for ocular and systemic angiogenesis programs.
Pipeline & Workflow Integration
This model bridges early discovery, lead identification, and preclinical validation for anti-angiogenic therapies targeting corneal and extraocular neovascularization.
- Discovery Biology: Enables hypothesis testing and mechanistic de-risking of angiogenesis pathways in vivo.
- Screening: Provides reproducible, quantitative endpoints for compound evaluation and assay standardization.
- Analytics: Supports statistical comparison of neovascularization, lymphangiogenesis, and corneal edema across experimental groups.
- Translational Research: Facilitates biomarker alignment and translational relevance to clinical chemical burn pathology.
- Enterprise Reuse: Offers a reusable, validated platform for ongoing anti-angiogenic drug and biologic screening.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in angiogenesis research.
- Operational Value: Enhances reproducibility, standardization, and scalability of preclinical efficacy studies.
- Strategic Value: Improves go/no-go decision-making and capital efficiency by providing robust in vivo data.
- Portfolio Impact: Enables risk-adjusted prioritization and advancement of ocular and angiogenesis-targeted assets.
Implementation Considerations
- Requires expertise in ocular microsurgery and animal handling for consistent injury induction.
- Demands access to immunostaining reagents (anti-CD31, anti-LYVE-1) and OCT imaging infrastructure.
- Necessitates cross-team standardization of injury parameters and scoring criteria for reproducibility.
- Adaptable to various genetic backgrounds and therapeutic modalities with protocol optimization.
- Limitations include potential variability in burn severity and the need for careful procedural control.
