A previously fit and healthy 26-year-old lady with no significant medical history presented with a two-month history of headaches. The headaches were prolonged, generalised, and unusually severe for the patient. Examination revealed papilloedema. The patient's optic nerve sheath diameter was measured 3 mm posterior to the globe and found to be 7.5 mm. The patient subsequently had computed tomog...

BACKGROUND/AIM Retrobulbar (optic) neuritis is inflammation of the optic nerve that may cause a complete or partial loss of vision. This inflammation can affect a part of the nerve within the eyeball (neuropapillitis) or a part of the nerve behind the eyeball (retrobulbar neuritis). The aim of this study was to establish whether there is a correlation between the diameter of a retrobulbar part ...

This study was undertaken to measure number, diameter and distribution of nerve fibers in normal human optic nerves. Twenty-two optic nerves of 19 subjects aged between 20 and 75 years were histomorphometrically examined using semithin sections obtained in a distance of 2 to 5 mm behind the globe. The mean nerve fiber count was 1,159,000 +/- 196,000 with a minimum of 816,000 and a maximum of 1,...

BACKGROUND Positive end-expiratory pressure (PEEP) can increase intracranial pressure. Pneumoperitoneum and the Trendelenburg position are associated with an increased intracranial pressure. We investigated whether PEEP ventilation could additionally influence the sonographic optic nerve sheath diameter as a surrogate for intracranial pressure during pneumoperitoneum combined with the Trendelen...

PURPOSE To describe optic disc variables assessed by evaluation of clinical optic disc photographs and to compare sensitivity and specificity of these optic disc parameters in identifying patients with ocular hypertension who have nerve fiber layer defects and normal visual fields and patients with visual field defects. METHODS The study included 500 normal subjects, 132 patients with ocular ...

Using an automated image analysis system, cross-sections from optic nerves of 17 normal cynomolgus monkeys were examined. The number of nerve fibers, their density, and the distribution of their diameters for whole nerves and for various regions of the nerve cross-section were estimated. The mean total number of fibers in the optic nerve was 1.2 million. The mean diameter of axons was 0.8 micro...