A new procedure for fundus photography and fluorescein angiography in small laboratory animal eyes

Abstract

Increasing interest in retinal research demands continuous improvement of experimental techniques and interpretation. Thus, the purpose of our research was to devise a new method for funduscopic photography and fluorescein angiography in the normal or diseased retina of the small laboratory animal that would produce results comparable in optical quality and field coverage to those obtained in human clinical practice. To enhance the view of the small eye, a 2.2 Volk Panretinal lens was held in apposition to the lens of a clinical fundus camera, the Topcon TRC 50FT, by means of a custom made metal sleeve. Albino mice, albino rats, and pigmented rats were photographed. Fluorescein angiography was performed on pigmented rats. Fluorescein was administered intravenously via the jugular vein at a dose of 5 mg/kg. Various speeds of film and flash settings were used depending on the light source and the pigmentation of the animal. Attachment of the 2.2 Panretinal lens to the clinical fundus camera allowed for more clearly defined fundus photographs of the small laboratory animal, as well as an enlarged field of observation over conventional techniques. Consequently, angiography fields and stages documented in the small laboratory animal approximated those obtained in human clinical practice. This technique facilitates the visualization of small fundi and it allows for a fuller documentation of experimental retinal models.