Optic disc

  • By admin
  • November 30, 2016
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Hi everybody, I am NF2er, I loss all hearing in my left ear and the tumor had been removed 5 years ago. Sorry for the recent spike but you are a T veteran of sort, having dealt with it for so long. Usage of the website does not substitute professional medical advice. Note the early vessel branching and trifurcation as the blood vessels exit the nerve. The vibrations are changed into nerve signals in the inner ear and are carried to the brain by the auditory nerve. The optic disc is placed 3 to 4 mm to the nasal side of the fovea. The harmless red and white blotches on the face and neck of certain stressed people illustrate the basic characteristics of PVD: The blood supply to a given organ is transiently not correctly adapted to the need of this organ.

The eye is unique because of the transparency of its optical media. Almost all eye structures can be examined with appropriate optical equipment and lenses. Using a modern direct ophthalmoscope gives a view of the optic disc using the principle of reversibility of light. A slit lamp biomicroscopic examination along with an appropriate aspheric focusing lens (+66D, +78D or +90D) is required for a detailed stereoscopic view of the optic disc and structures inside the eye. A biomicroscopic exam can give an indication of the health of the optic nerve. In particular, the eye care physician notes the colour, cupping size (as a cup-to-disc ratio), sharpness of edge, swelling, hemorrhages, notching in the optic disc and any other unusual anomalies. Anomalous vascular branching patterns depicted as an increased number of retinal vessels, early branching or trifurcation or both (Figure 1) are key features of ONHD.

The presence of blood behind the eardrum or bleeding from the ear, which may show the presence of CSF (halo sign) (Fig. A normal optic disc is orange to pink in colour. A pale disc is an optic disc which varies in colour from a pale pink or orange colour to white. A pale disc is an indication of a disease condition. Traditional colour-film camera images are the reference standard in imaging, requiring an expert ophthalmic photographer, ophthalmic technician, optometrist or an ophthalmologist for taking standardised pictures of the optic disc. Stereoscopic images offer an excellent investigative tool for serial follow-up of suspected changes in the hands of an expert optometrist or ophthalmologist. In recent times high resolution real-time video of the optic disc has allowed for the analysis of blood-flow and vasodilation in vessels in the area of the disc (epiCam) which may help to quantify both retinal and systemic disease.

Automated techniques have also been developed to allow for more efficient and less expensive imaging. Heidelberg Retinal Tomography (HRT-II), GDx-VCC and optical coherence tomography (Stratus-OCT 3) are the currently available computerised techniques for imaging various structures of the eyes, including the optic disc. 1. Auditory Perception – ability to identify, interpret, and attach meaning to sound. Imaging will not provide conclusive evidence for clinical diagnosis however, and the evidence needs to be supplanted by serial physiological testing for functional changes. Such tests may include visual field charting and final clinical interpretation of the complete eye examination by an eye care physician. Ophthalmologists and optometrists are able to provide this service.

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