The Aquaporin-1 Depletion Downregulates the Sclera Biomechanical Strength.

: To evaluate the relation of aquaporin-1 (AQP-1) expression and scleral biomechanical strength. : Guinea pigs with 3 weeks old received intravitreal injection of adeno-associated virus (AAV) containing AQP-1 or si-AQP-1 sequence, by which to up- or downregulate the AQP-1 expression in choroid. Animals were sacrificed 4 weeks after treatment. Then the expression of AQP-1 in the choroid was determined using western blotting, and the sclera stiffness recorded as Young's modulus was determined using tension test. The relation of AQP-1 expression and sclera stiffness was then analyzed. : Immunostaining revealed that AQP-1 protein expression was mainly observed in choroidal vascular endothelial cells layer. After the upregulation of AQP-1 expression, the scleral stiffness is slightly increased compared with that in control, but without significant difference. After the downregulation of AQP-1 expression, the scleral stiffness is lower than that in control group ( < .001). There is a positive relation between AQP-1 expression and sclera stiffness ( < .001). : The present study revealed that the AQP-1 depletion downregulates the sclera biomechanical strength, which provides information for better understanding the mechanism of myopia development.