title: Role of the lens and vitreous humor in the refractive properties of the eyes of three strains of goldfish.
abstract: Certain strains of goldfish are characterized by large bulging eyes which have been shown to be extremely myopic. Such myopia has been hypothesized to have its origin in enlargement of the posterior chamber of the eye. The focal length of the lens was found to be similar for paraxial and marginal lens zones in common, Chinese Black Moor and Celestial goldfish, thus providing indirect support of that hypothesis. Freeze-sectioning study of intraocular dimensions shows that the axial length of the vitreous chamber of the common goldfish eye is about 37% of total axial length. In contrast, it becomes more than 70% of axial length in Chinese Black Moors and Celestials. An examination of vitreous protein concentration indicates that ocular enlargement in Chinese Black Moors and in Celestials is related to an increase in vitreous quantity, and is accompanied by vitreous dilution. The fact that similar findings are reported in the case of experimental myopia in chicks, suggests the existence of a fundamental mechanism of refractive development for the vertebrate eye.
authors.affiliation: School of Optometry, University of Waterloo, Ontario, Canada.
authors.forename: R L
authors.initials: RL
authors.lastname: Seltner
authors.forename: J A
authors.initials: JA
authors.lastname: Weerheim
authors.forename: J G
authors.initials: JG
authors.lastname: Sivak
mesh_terms: D000818:Animals; D005123:Eye / Q000033:anatomy & histology; D005136:Eye Proteins / Q000378:metabolism; D006054:Goldfish; D007908:Lens, Crystalline / Q000033:anatomy & histology / Q000502:physiology*; D009216:Myopia / Q000503:physiopathology; D012029:Refraction, Ocular; D013045:Species Specificity; D014822:Vitreous Body / Q000502:physiology*
chemical_list: D005136:Eye Proteins