Refractive changes induced by form deprivation the mouse eye

PURPOSE. Form-deprivation myopia has been induced in many different animal species. Underlying mechanisms are not well understood to date. In the current study the possibility of inducing refractive errors by form deprivation in the mouse (C57 BL/6) was investigated. METHODS. Thirty animals underwent a 13- to 20-day monocular form-deprivation period by suture of the left eyelid before or after natural eye opening. A subsequent survival period was allowed in a group of animals. Retinoscopic refraction was performed at lid reopening and after the subsequent survival period, when applicable. Animals were killed and the eyes enucleated. The axial length of the eyes was measured in histochemically processed horizontal eye sections. A group of 30 age-matched normal control mice was also studied. RESULTS. Deprived eyes showed significant development of myopia compared with the contralateral fellow eye after transitory hypermetropia, regardless of whether they were deprived before or after natural eye opening. The refractive difference between form-deprived and corresponding fellow eyes was significantly correlated with the difference in axial length, which indicates that myopia is mainly axial. The differences exceeded those between eyes of age-matched normal control mice. CONCLUSIONS. Form-deprivation myopia can be induced in the mouse. This model may be useful to investigate underlying mechanisms of myopia in mammals, because of easier handling and availability of genetically manipulated strains.