USE OF OPTICAL COHERENCE TOMOGRAPHY IN BIRDS OF PREY

Abstract

In the last decade a new imaging technique has been developed, called Optical Coherence Tomography (OCT), used both in research and in the clinical practice of ophthalmology. It is a technique of in vivo microscopy that allows to evaluate the constitution and integrity of the ocular structures. The OCT expanded the possibilities in the segment of diagnostic imaging, providing greater reliability to the diagnosis and treatment of eye diseases. It is a non-invasive, high-resolution, non-contact, light-near-infrared examination in an interferometry system that produces sectional images.OCT is a recent examination in both human and veterinary ophthalmology. Some animals have already been evaluated by OCT, such as: birds, rodents, canines, felines and primates.This technique allows stratification of the layers of the anterior and posterior segments of the ocular bulb.It is believed that the high incidence of ocular trauma in predators is related to their ocular anatomy (eye layout, ocular structure and stability among other characteristics) and their housing in urban areas. The diagnosis of unrealized ocular lesions can lead to great visual damage or even loss of vision, which is of extreme importance for these hunting birds.Animals with lesions in the posterior ocular segment may present structural alteration and decrease in the thickness of the neurosensory retina, retinal pigment epithelium (RPE) and choroid, in addition to vitreitis. Changes in anterior ocular segment (corneal dystrophy, corneal degeneration, ulcer, bulb rupture and uveitis) can trigger important sequelae such as opacities and glaucoma. The objective of this study was to evaluate qualitatively and quantitatively the structures of the anterior and posterior segments of birds of prey, with and without ocular alteration, using the OCT technique. The birds to be used in the project will come from the Wild Animal Triage Center and / or Wildlife Rehabilitation Center (CETAS / CRAS). Fifteen birds will be used without eye disease, healthy, adults of undetermined sex (group without sexual dimorphism) and fifteen with eye disease.For the examination, the physical containment of the birds will be manual (with the aid of a towel or leather shawl) or pharmacological, by sedation. Such choice will depend on the patient's temperament, as the patient should remain motionless throughout the procedure so that good quality images can be obtained. It should be noted that the choice of drug to contain the animal will not interfere with the study. For the sedation, the combination of Midazolam (5mg / kg) and Ketamine (10mg / kg) will be applied intramuscularly. For pupillary dilation, animals will receive topical instillation of 10 mg / ml Rocuronium, one drop in both eyes every 15 minutes for 30 minutes, totaling 2 drops in each eye.The patient will be positioned properly and the operator will promote the alignment of the device and its focus, obtaining a clear image of the region to be studied in the monitor.This project aims to meet the expectations of a developing area, whose diagnostic improvement needs become essential for knowledge and maintenance of the patient's quality of life. The result of this study will have clinical applicability, making possible the diagnosis and follow-up of diseases that reach the anterior and posterior segment of the ocular bulb of the predators. (AU)