Electroretinography Changes in Feline Model of Iodoacetic Acid-induced Retinal Degeneration
10.3341/jkos.2019.60.12.1205
- Author:
Changzoo KIM
1
;
Myungshin LEE
;
Seung Uk LEE
;
Sang Joon LEE
Author Information
1. Department of Ophthalmology, Kosin University College of Medicine, Busan, Korea. hhiatus@gmail.com
- Publication Type:Original Article
- From:Journal of the Korean Ophthalmological Society
2019;60(12):1205-1215
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE:We explored changes in photoreceptor function and histology in an iodoacetic acid (IAA)-induced model of feline retinal degeneration.
METHODS:From January to October 2014, we studied 11 adult felines (22 eyes) over 2 years of age divided into two groups (two in a control and nine in an IAA group). The mean body weights of these two groups were 1.75 ± 0.35 and 1.61 ± 0.19 kg, and the male:female sex ratios 1:1 and 2:7, respectively. Electroretinograms (ERGs) were obtained before injection and at 1–4 week post-injection (20 mg/kg IAA). Standard paraffin retinal sections were stained with hematoxylin/eosin and other sections subjected to immunohistochemistry. We histologically evaluated the outer nuclear layer, and photoreceptor cone and rod cells.
RESULTS:In ERGs of the IAA group, both the rod and cone mean b wave amplitudes decreased significantly from week 1 to week 4 after injection (27.43, 29.41, 64.17, and 56.03; and 61.04, 51.25, 131.36, and 136.68 µV, respectively) compared to baseline (322.48 and 610.00 µV respectively) (p < 0.01). Optical microscopy revealed a significant decrease in the cell count of the outer nuclear retinal layer (16.83 ± 0.89 in the control and 11.98 ± 3.55 in the IAA groups, p < 0.01). Fluorescence microscopy revealed a significant reduction in the mean area per unit length of the rod cell layer (35,225.67 ± 2,477.02 and 14,903.62 ± 2,319.65 in the control and IAA groups, p < 0.01), but not in the cone cell count (26.16 ± 1.34 and 23.98 ± 6.16 in the control and IAA groups, p = 0.075).
CONCLUSIONS:ERGs revealed that functional b wave amplitudes fell after IAA-induce retinal degeneration in felines; histology showed that this was accompanied by reductions in the numbers of outer nuclear layers and rod cells. IAA induces photoreceptor degeneration in felines; further study is necessary.
