advertisement
BACKGROUND: Ocular hypertension is one of the most underdiagnosed ocular abnormalities among guinea pigs around the world. OBJECTIVES: The current study investigates the effect of 0.0015% preservative-free tafluprost ophthalmic solution (Zioptan) on the intraocular pressure of 16 healthy male guinea pigs (Cavia porcellus) under different light/darkness regimes. METHODS: All guinea pigs received a single drop of tafluprost at 5:30 in the right eye, whereas the contralateral eyes served as control to receive a placebo. Then, the animals were randomly divided into two groups; group A was exposed to light, whereas group B was placed in darkness from 5:30 to 18:00. Rebound tonometry (TonoVet) was instrumented to measure IOP values at 5:30 (baseline), 6:00, 7:00, 8:00, 9:00 and then every 3 h until 18:00. RESULTS: The maximum IOP reduction associated with tafluprost was observed at 6:00 by -1.4 ± 1.1 mmHg (p-value = 0.026) and -2.5 ± 1.2 mmHg (p-value = 0.011) in group A and B, respectively (repeated measure ANOVA test). There was a significant difference between the mean right and left eye IOP values in both groups at 5:30, 6:00, 7:00 and 8:00 (p-value <0.05), which was greater in amount in group B compared to group A due to the effect of darkness on IOP reduction. CONCLUSIONS: It is suggested that the variations of IOP in different light/dark conditions be taken into consideration when applying ocular hypotensive agents on guinea pigs' eyes.
Department of Clinical Sciences, Faculty of Specialized Veterinary Sciences, The Science and Research Branch of Islamic Azad University, Tehran, Iran.
Full article