A study of the effect of cyclopentolate cycloplegic on guinea pigs

Objective:To determine the efficacy and time course of cyclopentolate cycloplegia in neonatal guinea pigs used in experimental studies of refractive development.Methods:Three groups of three week old guinea pigs were used as subjects. Refractive states were monitored with streak retinoscopy. The subjects were grouped as following:①Group 1,the refractive states before and after cycloplegia were compared.②Group 2,accommodative changes were compared using cycloplegic doses of 2 drops(5 min interval) with that of 4 drops.③Group 3,accommodative changes were recorded at 30 min,60 min,90 min and 120 min after drops of cyclopentolate were topically applied 4 times at 5 minute intervals.Results:The accommodative state was stabilized after topical application of 1% cyclopentolate. Four drops at 5 min. intervals worked well. A wait of 60 to 90 minutes after cyclopia is recommended for a guinea pig model of myopia.Conclusion:Cycloplegia is necessary and efficient for examining the refractive state of neonatal guinea pigs. Optimal results for refraction can be obtained in 60 to 90 minutes after 1% cyclopentolate is topically applied in 4 drops at intervals of 5 minutes. [