Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Optic Neuritis


Related Terms

  • Retrobulbar Neuritis

Differential Diagnosis

Specialists

  • Neurologist
  • Ophthalmologist

Comorbid Conditions

  • Cardiovascular disease
  • Connective tissue disorders
  • Endocrine disorders
  • Gastrointestinal disorders
  • Neurologic conditions

Factors Influencing Duration

The severity of symptoms, the underlying cause of the condition, response to treatment, and the existence of complications may influence length of disability.

Medical Codes

ICD-9-CM:
377.30 - Optic Neuritis, Unspecified
377.32 - Neuritis, Retrobulbar, Acute
377.39 - Optic Neuritis, Other

Overview

Optic neuritis is an inflammation of the optic nerve that causes sudden loss of vision in part of the visual field, sometimes accompanied by pain in the eye associated with eye movement.

Various diseases may cause the condition, especially those, such as multiple sclerosis (MS), associated with loss of the optic nerve's protective fatty tissue (myelin) sheath. Bacterial, fungal, or viral infections elsewhere in the body may cause the condition.

Other causes of optic neuritis are decreased blood supply or injury to the optic nerve, autoimmune disorders such as systemic lupus erythematosus, tumors, cancer, and nutritional and metabolic disorders. Exposure to toxic chemicals, such as lead, may also cause the condition. A common form of optic neuritis, retrobulbar neuritis, is associated with development of multiple sclerosis (MS), especially in women.

Other diseases creating inflammation may be linked to development of optic neuritis, including birdshot chorioretinopathy, chronic inflammatory demyelinating polyneuropathy (CIDP), Guillain-Barré syndrome, sarcoidosis, Behçet's disease, and inflammatory bowel disease (ulcerative colitis, Crohn's disease). In rare cases, severe reaction to bee stings has led to optic neuritis. The condition may occur as an adverse reaction to vaccinations against smallpox, tetanus, diptheria, swine influenza, influenza, rabies, and hepatitis B.

Incidence and Prevalence: From 1.4 to 6.4 new cases of optic neuritis per 100,000 occur annually in the US (Graham).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Optic neuritis most often affects individuals in their 30's. More than 75% of those affected are women, and 85% are white (Eggenberger).

Source: Medical Disability Advisor



Diagnosis

History: Individuals may complain of eye pain that worsens with movement. Eyes may be tender when touched. Visual defects occurring over the first few hours gradually increase during the next several days. Blind gaps in vision (scotomas) are commonly reported visual defects. Individuals may also report loss of color perception. Vision loss usually occurs over a period of several days and may be mild or significant.

Physical exam: Pupil response to light may be slowed. Upon examination with a lighted instrument (ophthalmoscope), the optic nerve may at first appear normal. Follow-up exams may reveal that the edge of the optic nerve head (optic disc) has become blurry, and finally swollen, as the disease progresses. Small areas of bleeding (hemorrhages) near the optic nerve may be detected. In retrobulbar neuritis, the nerve inflammation occurs far enough behind the point in the retina where the optic nerve enters the eyeball at the optic disc that early changes are not evident.

Tests: Vision tests may include evaluation of visual acuity and visual field. With the high prevalence of MS associated with optic neuritis, a measurement of anatomical structures (MRI) may be performed to identify white lesions associated with loss of the optic nerve's protective sheath of fatty tissue (demyelination). This evidence is a strong indicator of MS. Sampling and analysis of cerebrospinal fluid (CSF) may be necessary to identify possible presence of MS.

Source: Medical Disability Advisor



Treatment

Only after careful consideration of benefits, anti-inflammatory drugs (steroids) may be given intravenously. Although treatment with steroids may aid the immediate return of vision, they seem to have little effect on the long-term outcome of the inflammatory process. Studies indicate that use of oral steroids alone increases the risk that optic neuritis will recur. Complications associated with use of steroids may outweigh benefits.

A form of optic neuritis found in the portion of the optic nerve behind the eyeball (retrobulbar neuritis), commonly associated with development of MS, generally resolves on its own. Early treatment with a drug that modifies biological responses (interferon) after diagnosis of optic neuritis reduced the rate of development of MS by 44% in one study and 35% in another ("Optic Neuritis").

Source: Medical Disability Advisor



Prognosis

Sudden onset (acute) forms of optic neuritis tend to improve within several weeks or months. Within a year, recovery from optic neuritis is considered good in about 95% of patients who are able to see at least at 20/40 or better (69% achieve 20/20 or better). But some symptoms, such as worsened depth perception, may linger. Other cases progress into wasting or degeneration of the optic nerve (optic atrophy) and may result in permanent blindness. Each recurrence produces further visual loss, and may eventually lead to optic nerve atrophy that results in permanent blindness. If caused by poor circulation, optic neuritis will often not improve. Optic neuritis is a strong indicator that MS could develop.

Source: Medical Disability Advisor



Complications

Use of oral steroids may cause the condition to recur, thus increasing chances of permanent vision loss. In severe cases, inflammation may spread to a large portion of the optic nerve to temporarily cause complete blindness. While earlier studies indicated that about 30% of individuals with optic neuritis are at risk of developing MS, more recent investigations indicate chances of developing MS in the decades following diagnosis may be much higher (Graham). Neuromyelitis optica, a complication of MS, involves deterioration of both optic nerves and the spinal cord.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

During a recovery period that may last several months, the individual with vision defects may be unable to perform tasks requiring keen visual acuity. Permanent vision loss may require accommodation such as larger and high-contrast print. Significant increase in illumination may be required at workstations. If vision loss is permanent, the individual may require reassignment to different tasks that do not require keen visual acuity.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Has diagnosis of optic neuritis been confirmed?
  • Does individual report painful eye movements?
  • Has individual experienced complications?
  • Does individual have an underlying condition that may impact recovery?
  • Has condition occurred before?

Regarding treatment:

  • Did treatment consist of oral steroids alone, or were IV steroids given as well?
  • Is individual a candidate for interferon?
  • Has individual been tested for the presence of multiple sclerosis?
  • Has administration of IV steroids helped resolve retrobulbar neuritis, or has it created complications?

Regarding prognosis:

  • Has individual's vision loss failed to resolve, continuing beyond a period of several months?
  • Does diagnosis need to be revisited?
  • Is current condition an initial episode or a recurrence of optic neuritis?
  • Did treatment include IV steroids or interferon?

Source: Medical Disability Advisor



References

Cited

"Optic Neuritis Treatment: Findings from Champs and ETMSS Study." American Academy of Ophthalmology. 2 Nov. 2004 <http://www.aao.org/aao/education/library/rapid/optic.cfm>.

Eggneberger, Eric R. "Inflammatory Optic Neuropathies." Ophthalmology Clinics of North America 14 (2004): 73-82. MD Consult. Elsevier, Inc. 2 Nov. 2004 <http://home.mdconsult.com/das/journal/view/39007776-2/N/11834617?sid=282895195&source=MI>.

Graham, Ken, and Joseph Rizzo. "A Review of Optic Neuritis." Digital Journal of Ophthalmology 5. Digital Journal of Ophthalmology. 2 Nov. 2004 <http://www.djo.harvard.edu/>.

Source: Medical Disability Advisor






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