Ultrasonic Assessment of the African Elephant (Loxodonta africana) Eye
American Association of Zoo Veterinarians Conference 2009
Priya Bapodra1,2,*, BVetMed, MSc, MRCVS; Tim Bouts2, DVM, MSc, MRCVS; Paul Mahoney1, BVSc, DVR, DECVDI, FHEA, MRCVS; Sally Turner3, MA, VetMB, DVOphthal, MRCVS; Ayona Silva-Fletcher1, BVSc, MSc, PhD; Michael Waters1, BVSc, MSc, MRCVS
1Royal Veterinary College, Hertfordshire, UK; 2Zoological Society of London, Bedfordshire, UK; 3Stone Lion Veterinary Centre, London, UK; *Present address: Department of Wildlife and Conservation Medicine, The Wilds, Cumberland, OH, USA


It is recommended that an ophthalmic examination is conducted as part of the annual physical examination of captive elephants.6 The ability to perform an ophthalmic examination in elephants is dependent on their level of training; hence lack of patient cooperation may create safety issues for handlers.6,8 Transpalpebral ultrasonography is regarded as a rapid and non-invasive imaging modality and would therefore prove useful in the examination of the live unsedated elephant.1,3,5,7 As there is no published work related to the use of ocular ultrasonography in elephants, the objective of this study was to describe the normal ultrasonographic appearance and measurements of the African elephant eye. This knowledge could then serve as a base for clinical ocular ultrasonographic examinations, where pathology may have caused alterations in the appearance and structural dimensions of the globe and intraocular structures.2,4,5

Six African elephants from the United Kingdom and Germany had bilateral transpalpebral ultrasound scans performed. Five females and one male with a mean age of 14.67±0.82 years (mean ± standard deviation) were included in the study population. Animals within the study group were maintained in free contact management systems. Ultrasound examinations were performed with animals in lateral recumbency, in a stretched position or standing. Continuous flow of low-pressure water was used as the contact medium between the ultrasound transducer (4–7 MHz broadband curvilinear) and the eyelid skin. Ocular biometry measurements were taken from images obtained by scanning through both the upper and lower eyelids.

Mean biometry measurements recorded for adult African elephants (n=6) were axial length 3.37±0.09 cm, equatorial diameter 3.80±0.24 cm, corneal thickness 0.17±0.03 cm, anterior segment depth 0.45±0.05 cm, lens diameter 1.99±0.25 cm, lens thickness 0.98±0.10 cm and posterior segment depth 1.75±0.10 cm. The ultrasonographic appearance of the globe and intraocular structures of the African elephant eye is similar to that in other species.2,4,5

Transpalpebral ultrasonography was found to be a useful imaging modality for the rapid and non-invasive assessment of the African elephant eye. Chemical restraint and local/topical anesthesia were not required to perform ocular ultrasonography and images of diagnostic quality were produced from all animals despite variable levels of training and handling. In summary, transpalpebral ultrasonography is a valuable imaging technique to produce useful information regarding the health of the globe and intraocular structures without the need for chemical restraint.

Literature Cited

1.  Nyland, T. G., and J. S. Mattoon. 1995. Veterinary Diagnostic Ultrasonography, 2nd ed. Saunders, Philadelphia, Pennsylvania. Pp. 305–324.

2.  Potter, T. J., G. D. Hallowell, and M. I. Bowen. 2008. Ultrasonographic anatomy of the bovine eye. Vet. Radiol. Ultrasound. 49: 172–175.

3.  Ramirez, S., and R. L. Tucker. 2004. Ophthalmic imaging. Vet. Clin. N. Am-Equine 20: 441–457.

4.  Rogers, M., R. E. Cartee, W. Miller and A. K. Ibrahim. 1986. Evaluation of the extirpated equine eye using B-Mode ultrasonography. Vet. Radiol. Ultrasound. 27: 24–29.

5.  Scotty, N. C. Ocular ultrasonography in horses. 2005. Clin. Tech. Equine P. 4: 106–113.

6.  Suedmeyer, K. 2007. Special senses. In: Fowler, M. E., and S. K. Mikota (eds.). Biology, Medicine and Surgery of Elephants, 1st ed. Blackwell Publishing, Ames, Iowa. Pp. 399–407.

7.  Whitcomb, M. B. 2002. How to diagnose ocular abnormalities with ultrasound. Proc. of the AAEP. Pp. 272–275.

8.  Wiedner, E. R., R. Isaza, L. E. Galle, K. Barrie, and W. A. Lindsay. Medical management of a corneal stromal abscess in a female Asian elephant (Elephas maximus). 2006. J. Zoo Wildl. Med. 37: 397–400.


Speaker Information
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Priya Bapodra, BVetMed, MSc, MRCVS
Royal Veterinary College
Hertfordshire, UK

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