June 1999
Volume 40, Issue 7
Free
Articles  |   June 1999
Naturally occurring vitreous chamber-based myopia in the Labrador retriever.
Author Affiliations
  • D O Mutti
    School of Optometry, University of California, Berkeley 94720-2020, USA.
  • K Zadnik
    School of Optometry, University of California, Berkeley 94720-2020, USA.
  • C J Murphy
    School of Optometry, University of California, Berkeley 94720-2020, USA.
Investigative Ophthalmology & Visual Science June 1999, Vol.40, 1577-1584. doi:
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      D O Mutti, K Zadnik, C J Murphy; Naturally occurring vitreous chamber-based myopia in the Labrador retriever.. Invest. Ophthalmol. Vis. Sci. 1999;40(7):1577-1584.

      Download citation file:


      © 2015 Association for Research in Vision and Ophthalmology.

      ×
  • Supplements
Abstract

PURPOSE: To investigate whether myopia is present in a breed of domestic dog, the Labrador retriever, and how the ocular components are related to refractive error in this breed. METHODS: Cycloplegic refractive error was measured in 75 Labrador retrievers by retinoscopy. Corneal and crystalline lens radii of curvature were measured in the right eyes of 57 of these dogs using a video-based keratophakometer, with axial ocular dimensions measured using A-scan ultrasonography. RESULTS: Of the 75 dogs tested, 11 (14.7%) were myopic by at least -0.50 D in one eye, and 6 (8.0%) were myopic in both eyes (full range of refractive errors, +3.50 D to -5.00 D). Of the 57 dogs with ocular component measurements, seven (12.3%) were myopic by at least -0.50 D in the right eye. There was a significant negative correlation between refractive error and vitreous chamber depth (Spearman r = -0.42; P < 0.001). Myopic eyes had an elongated vitreous chamber depth (10.87+/-0.34 mm for myopic dogs, 10.02+/-0.40 mm for nonmyopic dogs; P < 0.0001, Kruskal-Wallis test). There was also a significant quadratic association between lens thickness and vitreous chamber depth (P < 0.005; R2 = 0. 11), indicating that thinner lenses occurred at both shorter and longer vitreous chamber depths. CONCLUSIONS: Myopia in the Labrador retriever is analogous to human myopia in that it is caused by an elongated vitreous chamber. Thinner crystalline lenses found at longer vitreous chamber depths may be analogous to lens thinning documented in human ocular development. The Labrador retriever warrants investigation as a potential model of myopia that is naturally occurring rather than experimentally induced.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×