title: Mechanism of the DL-alpha-aminoadipic acid inhibitory effect on form-deprived myopia in guinea pig.
abstract: OBJECTIVE
  To investigate the effect of intravitreal injection of DL-alpha-aminoadipic acid (DL-α-AAA) on ocular refractive state and retinal dopamine, transforming growth factor-β2 (TGFβ2), vasoactive intestinal polypeptide (VIP) in guinea pig form-deprived myopia.
  
  
  METHODS
  Four-week-old pigmented guinea pigs were randomly assigned to 4 groups: normal control, deprivation, deprivation plus DL-α-AAA, deprivation plus saline. Form deprivation was induced with the self-made translucent eye shields, and lasted for 14 days. 8µg DL-α-AAA was injected into the vitreous chamber of deprived eyes. The corneal radius of curvature, refraction and axial length were measured. Retinal dopamine content was evaluated by the high-performance liquid chromatography with electrochemical detection, and TGFβ2 and VIP protein were detected by Western blotting.
  
  
  RESULTS
  Fourteen days of eye occlusion caused the axial length to elongate and become myopic in the form-deprived eyes, with the decrease of retinal dopamine and the increase of TGFβ2 and vasoactive intestinal polypeptide (VIP) protein. Intravitreal injection of DL-α-AAA could inhibit the myopic shift from (-3.65±1.06)D to (-1.48±0.63)D, P<0.01 due to goggles occluding and cause the decrease of retinal TGFβ2 protein in the deprived eyes. However, intravitreal injection of DL-α-AAA had no significant effect on retinal dopamine and VIP protein in deprived eyes. Retinal TGFβ2 protein correlated highly with the ocular refraction (y=-3.34+0.31/x, F=74.75, P<0.001) and axial length (y=8.39-0.02/x, F=48.32, P<0.001) in different treatment groups.
  
  
  CONCLUSIONS
  Intravitreal injection of DL-α-AAA is effectively able to suppress the development of form deprivation myopia, which may be associated with retinal TGFβ2 protein in guinea pigs.
authors: Department of Ophthalmology, Xiangya Hospital of Central South University, Changsha 410008, Hunan Province, China.
authors: Jun-Feng
authors: JF
authors: Mao
authors: Shuang-Zhen
authors: SZ
authors: Liu
keywords: DL-alpha-aminoadipic acid; Müller cell; TGFβ2; form-deprivation myopia; retina