The normal ultrasonographic anatomy and biometry of 60 adult sheep and 60 adult cattle eyes were evaluated by saline immersion technique. Five intraocular dimensions were taken: corneal thickness, aqueous chamber depth, lens diameter, vitreous chamber depth and axis bulbi. The eyes were then frozen and cut in a sagittal plane and the same dimensions were measured directly. Aand B-mode measurements were compared with each other and with that of direct measurements. There was no difference between Aand B-mode measurements. However, there was a difference between ultrasound and direct measurements.
Background: Hyperpneumatisation of the skull base and upper cervical vertebrae is a very rare condition of uncertain aetiology and pathophysiology. Case report: A case of extensive hyperpneumatisation of the craniocervical junction and upper three cervical vertebrae is described, in a patient who habitually performed the Valsalva manoeuvre to relieve the symptoms of a patulous eustachian tube. Reported symptoms of ear, neck and shoulder pain deteriorated after minor head trauma. There was a drastic radiological and clinical improvement after ceasing to perform the Valsalva manoeuvre. Discussion: All reported cases of craniocervical bone hyperpneumatisation have in common a history of raised middle-ear pressure, minor trauma or both. We therefore suggest that chronically raised middle-ear pressure leads to destruction of bony tissue and pneumatisation, and that this process is able to cross joints into the cervical spine, either via micro-fractures following trauma, or as a result of congenital assimilation of the craniocervical junction.
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