Antioxidant supplementation increases retinal responses and decreases refractive error changes in dogs.
The objective of the study was to examine whether a nutritional antioxidant supplementation could improve visual function in healthy dogs as measured by electroretinography (ERG) and autorefraction. A total of twelve Beagles, 6 to 8 years of age, with normal eyes upon indirect ophthalmoscopy and slit lamp biomicroscopy, were age and sex matched and randomly assigned to receive a feeding regimen for 6 months with or without a daily antioxidant supplementation. Portable, mini-Ganzfeld ERG and a Welch Allyn hand-held autorefractor were used to test retinal response and refractive error in the dogs at baseline and at the end of the supplementation period. All ERG a-wave amplitudes obtained were increased in the treatment group compared with those of dogs in the control group, with significant improvements in the scotopic high and photopic single flash cone ERG responses (P < 0·05 for both). For the b-wave amplitudes, all responses were similarly increased, with significant improvements in responses for the scotopic high light intensity stimulation (P < 0·05), and for photopic single flash cone and 30 Hz flicker (P < 0·01 for both) recordings. Change in refractive error was significantly less in the treatment group compared with that of the control group during the 6-month study (P < 0·05). Compared with the control group, the antioxidant-supplemented group showed improvement to varying degrees for retinal function and significantly less decline in refractive error. Dogs, like humans, experience retinal and lens functional decline with age. Antioxidant supplementation as demonstrated may be beneficial and effective in the long-term preservation and improvement of various functions of the canine eye.
Nestlé Research Center , St Louis , MO , USA.
Wei
W
Wang
Nestlé Purina Research , St Joseph , MO , USA.
Jerome
J
Hernandez
Department of Veterinary Medicine and Surgery College of Veterinary Medicine , University of Missouri , Columbia , MO , USA.
Cecil
C
Moore
Nestlé Research Center , St Louis , MO , USA.
Janet
J
Jackson
Department of Veterinary Medicine and Surgery College of Veterinary Medicine, University of Missouri, Columbia, MO, USA; Department of Ophthalmology, Mason Eye Institute, University of Missouri, Columbia, MO, USA.
Kristina
K
Narfström
Antioxidants; Canine nutrition; Dogs; ERG, electroretinography; Electroretinography; PRCD, progressive rod–cone degeneration; Pc, photopic single-flash; Pfl, photopic flicker; Refractive error; Retina; Sh, scotopic high-intensity; Ssd, scotopic standard intensity; Visual acuity