Establishment of monocular-limited photoreceptor degeneration models in rabbits.

Abstract

BACKGROUND:

Numerous rodent models of photoreceptor degeneration have been developed for the study of visual function. However, no viable model has been established in a species that is more closely related to Homo sapiens. Here, we present a rabbit model of monocular photoreceptor degeneration.

METHODS:

We tested 2 chemicals, verteporfin and sodium nitroprusside (SNP), for developing a 1-eye limited photoreceptor degeneration model in pigmented rabbits. After the intravenous injection of verteporfin, the retina was exposed to light from a halogen lamp for 0, 10, 30, or 60 min. Alternately, 100 μL of various concentrations of sodium nitroprusside (0.1 mM, 0.5 mM, and 1 mM) were intravitreously injected into the rabbit eye. Retinal degeneration was evaluated by fundus photography, electroretinogram (ERG), and histological examinations.

RESULTS:

Fundus photographs of animals in the verteporfin- or SNP-treated groups showed evidence of retinal degeneration. The severity of this degradation depended on the duration of light exposure and the concentration of SNP administered. The degeneration was clearly limited to the light-exposed areas in the verteporfin-treated groups. Extensive retinal atrophy was observed in the SNP-treated groups. The a- and b-wave amplitudes were dramatically decreased on the ERGs from SNP-treated groups. Histological examination revealed that either verteporfin or SNP induced severe photoreceptor degeneration. High-dose SNP treatment (1 mM) was also associated with inner retinal layer degeneration.

CONCLUSIONS:

Both SNP and verteporfin clearly caused photoreceptor degeneration without any effect on the contralateral eye. These compounds therefore represent valuable tools for the empirical investigation of visual function recovery. The findings will inform guidelines for clinical applications such as retinal prostheses, cell-based therapy, and gene therapy.

• Authors: Hitomi Isago, Eriko Sugano, Namie Murayama, Makoto Tamai, Hiroshi Tomita
• Journal: BMC ophthalmology (BMC Ophthalmol) Vol. 13 Pg. 19 (May 17 2013) ISSN: 1471-2415 [Electronic] England
• PMID: 23683117 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Photosensitizing Agents
• Porphyrins
• Vasodilator Agents
• Verteporfin
• Nitroprusside

Topics

• Animals
• Disease Models, Animal
• Electroretinography
• Injections, Intravenous
• Light
• Nitroprusside
• Photography
• Photoreceptor Cells, Vertebrate (drug effects, radiation effects)
• Photosensitizing Agents (pharmacology)
• Porphyrins
• Rabbits
• Retinal Degeneration (chemically induced, pathology)
• Vasodilator Agents (pharmacology)
• Verteporfin