Purpose: The authors recently used topical endoscopy to image the mouse eye fundus. Here, they widened the field of application for this ophthalmologic tool, imaging both the posterior and the anterior eye segments in larger animals commonly encountered in research laboratories and veterinary clinics.
Methods: Pupils were dilated, and local anesthetic and gel were applied to the animal cornea. The endoscopic probe was placed in contact with the cornea of conscious rats, sedated cats and dogs, anesthetized sheep, and nonhuman primates.
Results: High-resolution digital images of the eye fundus were obtained in all investigated animals using the endoscopic probe along the eye axis. Arteriovenous filling time was monitored with fluorescein angiography in pigmented rats. The retinal periphery and ciliary bodies could be visualized with the probe placed at an oblique angle. The probe was inclined further to observe the iridocorneal angle such that the pectinate ligaments could be seen at high resolution in cats. The authors used the probe on eyes with retinal detachment, luxation of a cataractous lens, and pigment infiltration in the iridocorneal angle, demonstrating its potential use in eye diseases.
Conclusions: This topical endoscopic technique provides a unique tool for single eye examinations. The authors obtained a circular view of the anterior (iridocorneal angle) and the posterior (fundus) eye segments from all animal species studied. This technique is inexpensive and easy to use. It can be easily moved to the eye of the patient who cannot move to stand in front of classic apparatus, offering new opportunities in ophthalmology.