Evaluation of monkey intraocular pressure by rebound tonometer

Area of Science:

• Ophthalmology
• Veterinary Medicine
• Medical Devices

Background:

• Intraocular pressure (IOP) is a critical factor in ocular health, with abnormal levels often indicating disease.
• Accurate and reliable IOP measurement is essential for diagnosis and monitoring treatments.
• Non-invasive tonometry methods are sought after for their ease of use and reduced patient discomfort.

Purpose of the Study:

• To evaluate the accuracy and utility of the TonoVet rebound tonometer for measuring IOP in a non-human primate model.
• To assess the TonoVet's capability in detecting physiological and pharmacological changes in IOP.

Main Methods:

• The TonoVet tonometer's accuracy was validated against controlled IOP in anesthetized rhesus monkeys using a cannulated eye model.
• In vivo studies assessed diurnal IOP variations and the impact of IOP-modulating drugs.

Main Results:

• TonoVet IOP readings showed a strong positive correlation (r²=0.97) with actual IOP in controlled settings.
• The tonometer successfully demonstrated diurnal IOP fluctuations in rhesus monkeys.
• Topical H1152 (rho kinase inhibitor) significantly reduced IOP by 5-6 mmHg for at least 4 hours.
• Travatan (prostaglandin agonist) induced transient IOP increase followed by a sustained reduction with repeated dosing.

Conclusions:

• The TonoVet rebound tonometer provides accurate IOP measurements in rhesus monkeys.
• The device is user-friendly and suitable for in vivo studies of IOP dynamics and drug efficacy.