Three Dimensional Ultrasonography of the Eye and Measurement of Optical Nerve Sheet Diameter in Dog

Objective- To determine the possibility of three-dimensional ultrasonography (3DUS)and measurement of optical nerve sheet by this method.Design- Descriptive study.Animals- 10 mixed normal dogs (5males, 5 females), age 1-1.5 year, and weighting 15±5kgProcedure- 3D ultrasounds of the eyes were evaluated and the normal optical nerves in3DUS images were measured using Volouson 730 pro.Results- In the obtained 3D images vitreous body, anterior chamber, and lens cortex andnucleus showed a distinct anechogenic to hypoechogenic. Details of the eyescompartments were better observed by rotating the images in all possible angles andplanes using 3D facilities. Anterior and posterior lens capsule and the optic disk werehyperechogenic. The mean optical nerve in males was: 3.85 mm and in females it was3.86mm. There weren’t a significant difference between ocular nerve measurements ofmale and female dogs and left and right eyes.Conclusion and Clinical Relevance- The 3DUS gives useful images for teaching anddiagnostic purpose and Lesions of the caudal portion of the orbit (e.g. optic nerveatrophy) are better visualized by this technique. The results of the eye 3DU in dogsshowed marked advantages in image acquisition for interpretation of all aspects of theocular structures. Measurement of the optic nerve by 3D ultrasonography and othermethods such as CT scan and direct measurement did not have any significant difference.