The Significance of the Ocular Pain Model

Ocular pain, discomfort, and itching are intractable symptoms of many eye conditions, such as dry eye, infectious eye disease, allergic eye disease, and ocular trauma, which can develop into chronic neuropathic pain disorders in severe cases. These symptoms are triggered by disease pathology affecting specialized nerves of the trigeminal ganglion that express distinct sensory receptors, including multimodal nociceptors and thermoreceptors. In animal models, the assessment of pain and discomfort must rely on the interpretation of animal behavioral observations related to pain. This can lead to subjectivity and variability in results, adding to drug development challenges for ocular pain and discomfort. In addition, the utility of these models in eye pain drug development is unclear due to the variability and unclear translatability of animal-specific behaviors to human symptoms, further limiting research in humans. Therefore, there is an urgent need for an evaluation model that directly addresses the unmet need for drugs to address ocular discomfort and pain in clinical studies.

Fig. 1. A simplified version of the ocular sensory pathway. First-order neuron (solid line) with nerve ending in the cornea, cell body in the trigeminal ganglion, and synapse in the subnucleus caudalis. (Galor A, et al., 2019)

Service Overview

Many preclinical animal models can be used to assess inflammation, dry eye, and ocular allergic disease. However, they cannot readily assess subjective assessments of other pain modes assessed in humans. Ace Therapeutics has discovered a rabbit ocular pain model by exploring noxious stimuli that cause pain and discomfort in animals. These stimuli include strong evaporation, high osmotic pressure, irritants, injury, inflammation activation, etc. This model can be used to study inflammation, injury, or eye pain after a dry eye condition, thus improving the chances of developing drugs for eye pain.

Explore Ace Therapeutics' Rabbit Models of Ocular Pain

Capsaicin, a TRPV1 agonist, produces immediate pain sensations such as eyelid squeezing, vocalization, and ocular irritation (including conjunctival edema and hyperemia) when applied topically. Our researchers induce eye pain by applying capsaicin to the ocular surface of New Zealand white rabbits, and measured the following indicators at different time points as evaluation endpoints, including but not limited to:

• The number of eyelid-squeezing movements.
• The degree of palpebral opening.
• Miotic response.
• The degree of conjunctival vasodilation evoked.
• Tear secretion measurement.
• Thermal/mechanical sensitivity.

In addition, our researchers select clinically relevant compounds to fully characterize the rabbit eye pain model.

Application Fields

• Research on ocular pain after dry eye, keratoconjunctivitis, glaucoma, and ocular hypertension.
• Explore the neural mechanisms that regulate intraocular pressure and ion K+ and Cl– channels.
• In-depth understanding of ocular pathophysiology.

Thanks to a deep understanding of ocular surface diseases, Ace Therapeutics provides a powerful experimental tool to meet the needs of ocular pain research for global customers. If you are interested in our services or need more detailed information, please feel free to contact us. Our experienced scientists are ready to help you!

References

1. Shah M, Cabrera-Ghayouri S, Christie LA, et al. Translational Preclinical Pharmacologic Disease Models for Ophthalmic Drug Development. Pharm Res. 2019, 36(4):58.
2. Galor A, Levitt RC, Felix ER, et al. Neuropathic ocular pain: an important yet underevaluated feature of dry eye. Eye (Lond). 2015, 29(3):301-12.
3. Kaido M, Inoue S, Kawashima M, et al. Capsaicin-induced pain sensitivity in short tear break-up time dry eye. Ocul Surf. 2020, 18(4):620-626.

• Customized Rabbit Models of Retinal Neovascularization
• Customized Rabbit Models of Dry Eye Disease
• Customized Rabbit Models of Corneal Neovascularization
• Customized Rabbit Models of Normotensive & Hypertensive Intraocular Pressure
• Customized Rabbit Models of Uveitis
• Customized Rabbit Models of Proliferative Vitreoretinopathy
• Customized Rabbit Models of Corneal Endothelial Injury
• Customized Rabbit Models of Retinoblastoma
• Customized Rabbit Models of Uveal Melanoma

• * Name:
• Phone:
• * Email:
• * Services or Products of Interest:
• Project Description:
• * All of our services and products are intended for preclinical research use only and cannot be used to diagnose, treat or manage patients.

  * Tick to confirm the Research Use Only (RUO) statement.

• Submit