What Types of Eye Protection Should be Worn?
The eye protection chosen for specific work situations depends upon the circumstances of exposure, other PPE used, and personal vision needs. There is wide variety in the types of protective eyewear, and appropriate selection should be based on a number of factors, the most important of which is the nature and extent of the hazard.
Eye protection must be comfortable and allow for sufficient peripheral vision and must be adjustable to ensure a secure fit. It may be necessary to provide several different types, styles, and sizes. Selection of protective eyewear appropriate for a given task should be made from an evaluation of each activity, including regulatory requirements when applicable. These hazard assessments require a clear understanding of the work tasks, including knowledge of the potential routes of exposure and the opportunities for exposure in the task assessed (nature and extent of worker contact).
Exposure incident reports should be reviewed to identify those incidents (whether or not infection occurred) that could have been prevented by the proper use of protective eyewear.
Definition of Optic Nerve
The optic nerve connects the eye to the brain. The optic nerve carries the impulses formed by the retina, the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images. Using an ophthalmoscope, the head of the optic nerve can be easily seen. It can be viewed as the only visible part of the brain (or extension of it).
The optic nerve is the second cranial nerve. The cranial nerve emerge from or enter the skull (the cranium), as opposed to the spinal nerves which emerge from the vertebral column. There are twelve cranial nerves.
In terms of its embryonic development, the optic nerve is a part of the central nervous system (CNS) rather than a peripheral nerve.
The word “optic” comes from the Greek “optikos”, pertaining to sight.
Aside from the optic nerve, the eye has a number of other components. These include the cornea, iris, pupil, lens, retina, macula, and vitreous.
Risk factors of Optic Neuritis
Risk factors for optic neuritis arising from autoimmune disorders include:
* Age. Optic neuritis most often affects young adults ages 20 to 45 years; the average age of onset is about 30 years. Older people or children also can develop optic neuritis, but it occurs less frequently in these groups.
* Sex. Women are twice as likely as men are to develop optic neuritis.
* Race. Optic neuritis occurs more in whites than in other races.
* Genetic mutations. Certain genetic mutations may increase your risk of developing optic neuritis or multiple sclerosis.
Treatment of Optic Neuritis
Optic neuritis usually gets better on its own. In some cases, steroid medications are used to treat optic neuritis, because they help reduce inflammation in the optic nerve. If you receive steroids, your treatment may involve:
* Intravenous steroids. You’ll likely receive steroid therapy by vein (intravenously) for several days. Intravenous steroid therapy may accelerate vision recovery, but it doesn’t appear to affect the extent to which you’ll recover your vision.
* Oral steroids. After intravenous steroid therapy, you may take an oral steroid called prednisone for several weeks. Oral steroids usually follow an intravenous course of steroids, because using oral steroids alone to treat optic neuritis has been associated with an increased risk of recurrence.
In instances in which steroid therapy has failed and severe vision loss persists, a treatment called plasma exchange therapy may help some people recover their vision.
A course of intravenous corticosteroids (steroids) followed by oral steroids has been found to be helpful in restoring vision quickly to patients with MS-related episodes of optic neuritis, but its efficacy in preventing relapse is debatable. The Optic Neuritis Treatment Trial (ONTT) has shown that IV steroids may be effective in reducing the onset of MS for up to two years, but further studies are necessary. Oral prednisone has been found to increase the likelihood of recurrent episodes of optic neuritis, and is not recommended for treating the disorder.
Diagnosis of Optic Neuritis
An ophthalmologist, a physician trained in diseases of the eye, will typically make a diagnosis of optic neuritis. A complete visual exam, including a visual acuity test, color vision test, and examination of the retina and optic disc with an ophthalmoscope, will be performed. Clinical signs such as impaired pupil response may be apparent during an eye exam, but in some cases the eye may appear normal. A medical history will also be performed to determine if exposure to toxins such as lead may have caused the optic neuritis.
Further diagnostic testing such as magnetic resonance imaging (MRI) may be necessary to confirm a diagnosis of optic neuritis. An MRI can also reveal signs of multiple sclerosis.
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