The Additional Diagnostic Value of Optical Coherence Tomography (OCT) and Its Application Procedure in A Wide Variety of Avian Species
|Panagiotis N Azmanis1#, Franziska G Rauscher2#*, Beatrice Werner3#, Jens Huebel1, Christian Koch2,3, Wencke Vetterlein4, Nicole Körber3, Jens Thielebein5, Andreas Reichenbach4, Peter Wiedemann2, Mike Francke3,4 and Maria-Elisabeth Krautwald-Junghanns1|
|1Clinic for Birds and Reptiles, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 17, 04103 Leipzig, Germany|
|2Department of Ophthalmology, University Hospital, University of Leipzig, Liebigstraße 10-14, 04103 Leipzig, Germany|
|3Translational Centre for Regenerative Medicine (TRM), University of Leipzig, Philipp-Rosenthal-Straße 55, 04103 Leipzig, Germany|
|4Paul Flechsig Institute of Brain Research, Pathophysiology of Neuroglia, University of Leipzig, Liebigstraße 19, 04103 Leipzig, Germany|
|5Institute of Agricultural and Nutritional Science, Martin-Luther-University Halle-Wittenberg, Theodor-Lieser-Straße 11, 06120 Halle (Saale), Germany|
|#These authors contributed equally to the work.|
|Corresponding Author :||Franziska Rauscher
PhD, Research fellow
Department of Ophthalmology
04103 Leipzig, Germany
Telephone: 0049 341 9721512
Fax: 0049 341 9721659
E-Mail: [email protected]
|Received March 23, 2015; Accepted June 05, 2015; Published June 10, 2015|
|Citation: Azmanis PN, Rauscher FG, Werner B, Huebel J, Koch C et al. (2015) The Additional Diagnostic Value of Optical Coherence Tomography (OCT) and Its Application Procedure in A Wide Variety of Avian Species. J Clin Exp Ophthalmol 6:431. doi: 10.4172/2155-9570.1000431|
|Copyright: © 2014 Azmanis PN, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
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Objective: The current study introduced OCT as a novel tool in clinical veterinary ophthalmology in a much wider variety of free-living avian species than hitherto studied.
Methods: OCT was tested and performed in 39 free-living birds (21 species of 12 families) and compared to direct ophthalmoscopy. Birds were examined with combinations of different restraints (manual restraint or fixation on a holding device) and different anaesthesia regimes (none, sedation, general anaesthesia). Inter- and intra-species specific variations of the general procedure, the restraint methods and the clinical findings were evaluated.
Results: OCT was possible in all examined avian species (from 40 g up to 7720 g) and superseded direct ophthalmoscopy in quality and quantity of ophthalmological findings. All restraint methods enabled OCT examination, however combination of general anaesthesia and a holding device provided the most rapid and subjectively the least stressful examination technique. Stability, stress reduction, head angle and distance from the OCT device were important factors influencing volume scanning quality. Sixteen, out of 39 birds, presented ocular abnormalities detected by OCT (compared to only five birds when using direct ophthalmoscopy). OCT with included fundus images offered an objective assessment of retinal changes. Retinal abnormalities included changes of fundus pigmentation, drusenoid changes and severe retinal and choroidal degenerations. Species-specific variations of retinal layer dimensions and of foveal structures were evident.
Conclusion: OCT is a promising, non-invasive method, which significantly compliments standard techniques. OCT is applicable to a wide variety of avian species; it provides high quality cross-sectional images of the retina, enabling accurate and improved diagnosis and prognosis of therapies. An assessment of the visual capabilities of traumatised birds is a major factor for their rehabilitation and survival in the wild. Finally, this method is an excellent tool in interdisciplinary retinal research, providing novel insights into the diversity of very specialized structural adaptations of avian retina.