title: [Effects of experimentally induced hyperopic optical defocus on refractive status of adolescent monkeys].
abstract: OBJECTIVE
  To determine if chronic optical defocus alters refractive development in monkeys at ages corresponding to the typically developed age of myopia in human children.
  
  
  METHODS
  A hyperopic anisometropia was produced in 7 adolescent rhesus monkeys by photorefractive keratectomy (PRK). The laser procedures were performed when the monkeys were 2.0 to 2.5 years old, which corresponded to approximately 8-10 years old in human being. The ocular effects of the induced anisometropia were assessed periodically by corneal topography, retinoscopy and A-scan ultrasonography.
  
  
  RESULTS
  By about 30 days post-PRK, the experimentally induced refractive errors was stabilized and the treated eyes were between +0.75 and +2.25 D more hyperopic than their fellow eyes. Subsequently, 7 monkeys showed systematic reductions in the degree of anisometropia. Although some regression in corneal power occurred, the compensating refractive changes were primarily due to the differences in vitreous chamber growth (r = 0.74, P = 0.046).
  
  
  CONCLUSIONS
  Vision-dependent mechanisms that are sensitive to refractive error are still active in adolescent primates and probably play a role in maintaining stable refractive errors in the two eyes. Consequently, conditions that result in consistent hyperopic defocus could potentially contribute to the development of juvenile onset myopia in children.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. xingzh88@hotmail.com
authors.forename: Xing-wu
authors.initials: XW
authors.lastname: Zhong
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
authors.forename: Xiao-lian
authors.initials: XL
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Tan
authors.forename: Hao-hui
authors.initials: HH
authors.lastname: Nie
mesh_terms: D000818:Animals; D015858:Anisometropia / Q000503:physiopathology*; D048988:Corneal Surgery, Laser; D006956:Hyperopia / Q000503:physiopathology*; D008253:Macaca mulatta; D009216:Myopia / Q000503:physiopathology