December 2002
Volume 43, Issue 13
ARVO Annual Meeting Abstract  |   December 2002
Intraretinal pH Distribution in Diabetic Cats
Author Affiliations & Notes
  • E Budzynski
    Department of Biomedical Engineering
    Northwestern University Evanston IL
  • ND Wangs-Wirawan
    Department of Biomedical Engineering
    Northwestern University Evanston IL
  • RA Linsenmeier
    Departments of Biomedical Engineering and Neurobiology & Physiology The Institute of Neuroscience
    Northwestern University Evanston IL
  • L Padnick-Silver
    Department of Biomedical Engineering
    Northwestern University Evanston IL
  • Footnotes
    Commercial Relationships   E. Budzynski, None; N.D. Wangs-Wirawan, None; R.A. Linsenmeier, None; L. Padnick-Silver, None. Grant Identification: Support: NIH Grant EY05034
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 1329. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      E Budzynski, ND Wangs-Wirawan, RA Linsenmeier, L Padnick-Silver; Intraretinal pH Distribution in Diabetic Cats . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1329.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Abstract: : Purpose: The intraretinal distribution of H+ in cats with long-standing diabetes was examined in order to understand changes in pH during diabetic retinopathy. Methods: H+-selective microelectrodes were used to measure intraretinal extracellular H+ concentration ([H+]O) in the retina of anesthetized cats. The four animals had varied stages of diabetic retinopathy based upon fundoscopic evaluation. The profiles of [H+]O as a function of retinal depth were fitted with a three-layer diffusion model to extract values for H+ production in the outer retina. Profiles were recorded in "normal" and damaged areas of the retina and were compared to profiles recorded in the retina of normal cats. Results: In normal animals the pH in the middle of the retina is lower than in the vitreous, and the profile shape indicated that there was clearance of H+ by both the retinal and choroidal circulations. Profiles in diabetic animals were classified as "normal" or damaged, based upon the H+ clearance in the inner retina. Profiles with a pH difference of less than 0.02 pH units between mid-retina and vitreous were considered damaged. "Normal" diabetic areas had an H+-clearance that was significantly greater than that seen in normal retinas. Damaged diabetic areas had an H+-clearance that was significantly lower than both normal retinas and "normal" diabetic areas. The average inner retinal [H+]O was significantly increased in diabetic cats (7.86 ± 1.9 x 10-8 M) compared to normal animals (7.04 ± 1.4 x 10-8M). The average production of H+ in the outer retina was greater in the "normal" areas (4.0 ± 3.1 x 10-9 mol/L/sec) than in the damaged areas (1.9± 1.4 x 10-9 mol/L/sec) of the diabetic retina. Conclusions: H+ distribution in the diabetic retina varies from "normal" to damaged areas. It appears that diabetes leads to acidification of the inner retina. In areas of capillary occlusion, H+ production by photoreceptors is also impaired.

Keywords: 388 diabetic retinopathy • 512 PH regulation/protons • 554 retina 

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.