Purpose:
This study investigates the changes in intraocular pressure (IOP), aqueous flow (Fa), outflow facility and central corneal thickness (CCT) before, during and after puberty in male Dutch Belted rabbits.
Methods:
Measurements were made in one group of 11 rabbits at the age of 9 (juvenile), 15 (puberty), 20 (post-puberty) and 27 weeks (young adult), and a second group at 42 weeks of age (mature adult). Measurements were made between 11 PM and 5 AM. Aqueous flow was measured by fluorophotometry and IOP by pneumatonometry. Outflow facility was determined by tonography (Cton). CCT was measured by pachymetry. A repeated measures ANOVA was used for statistical comparisons. P values< 0.05 were considered statistically significant.
Results:
IOPs were significantly lower in 27 and 42 week old rabbits compared to the younger ages. Aqueous flow slowed at 20 weeks of age and older. Outflow facility was significantly decreased at 20 weeks but returned to prepuberty levels thereafter. CCT increased gradually with time. The table provides a summary of results (means±SEM).
Conclusions:
Around the time of puberty, aqueous flow decreases but IOP remains stable because outflow facility also decreases. In the adult rabbit, the outflow facility but not the aqueous flow returns to prepuberty levels causing IOP to decrease. The rabbit eye undergoes dramatic changes in aqueous humor dynamics during puberty, some of which appear to be permanent and some of which are not.
Keywords: aqueous • intraocular pressure