Friday, February 09, 2007

Vision Examination

Don’t be surprised if at your next visit, we photograph of the back of your eye. These pictures are necessary to document the health of the optic nerve, vitreous, macula, retina and its blood vessels. The photographs are used for comparison, documentation, and sometimes to diagnose certain eye conditions and also help with the detection of hypertension (high blood pressure) and cholesterol, among other things. It is the only way we can see what is happening in the body without surgery – the eye is far more than the window to the soul!

Fundus photography is a process using special optical imaging equipment e.g., cameras to photograph structures of the eye. Fundus photography allows for interpretation and report to document a disease process or follow the progress of a disease. Photographs may also be necessary to plan treatment for a disease process.

Because fundus photography is a highly specialized form of medical imaging, it can’t be done with an ordinary camera. It requires a customized camera that is mounted to a microscope with intricate lenses and mirrors. These high-powered lenses are designed so the photographer can visualize the back of the eye by focusing light through the cornea, pupil and lens.

Fundus is the bottom or base of anything. In medicine, it is a general term for the inner lining of a hollow organ.

Have you ever taken a fundus photograph? If you have taken photographs of your family or friends using a flash attachment on your camera and noticed that they have "red eyes", then you have! Photographic red eye is nothing more than a reflection of light off of the fundus of the eye. When performing ophthalmic fundus photography for diagnostic purposes, a special camera called a fundus camera is used to focus on the fundus. The resulting images can be spectacular, showing the optic nerve through which visual "signals" are transmitted to the brain and the retinal vessels which supply nutrition and oxygen to the tissue set against the red-orange color of the pigment epithelium.

Color images like the one above provide documentation of the ocular fundus. The retina is the "film" of the eye. Images passing through the clear structures of the cornea and lens are focused there to give us our view of the world. The fundus camera can document the condition of this miraculous anatomical structure. Retinal abnormalities are among the first complications to develop in persons with glucose intolerance, and retinopathy is an extremely sensitive indicator of diabetes.

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