Reproductive status effects on intraocular pressure in Mares

This study investigates the potential relationship between intraocular pressure (IOP) and serum progesterone (SP) concentrations in seven clinically healthy, non-pregnant mares. Measurements of IOP and SP were taken at various stages of the estrous cycle and during the anestrous season, using randomized testing for each eye through rebound tonometry (Tono-Vet® tonometer, iCare). Reproductive evaluations included abdominal palpation per rectum and ultrasonography to determine estrous cycle stages. Analysis revealed moderate to strong positive correlations between SP concentrations and IOP, with the right eye showing a moderate correlation (≈0.467) and the left eye a stronger one (≈0.609). These findings suggest that the reproductive status of mares influences IOP, indicating a potential role of progesterone in IOP variations throughout the estrous cycle in mares.