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.

Corneal Ulcer


Related Terms

  • Ulcerative Keratitis

Differential Diagnosis

Specialists

  • Ophthalmologist

Comorbid Conditions

  • Immune system disorders

Factors Influencing Duration

The type of treatment, the individual's response to treatment, or the presence of complications may influence length of disability.

Medical Codes

ICD-9-CM:
370.00 - Keratitis; Corneal Ulcer, Unspecified
370.01 - Keratitis; Marginal Corneal Ulcer
370.02 - Keratitis; Ring Corneal Ulcer
370.03 - Keratitis; Central Corneal Ulcer
370.04 - Keratitis; Hypopyon Ulcer; Serpiginous Ulcer
370.05 - Keratitis; Mycotic Corneal ulcer
370.06 - Keratitis; Perforated Corneal Ulcer
370.07 - Keratitis; Moorens Ulcer

Overview

© Reed Group
A corneal ulcer is a break or erosion in the clear front layer of the eye (cornea) that may be caused by an injury or infection. Although usually superficial, ulcers sometimes can extend into the underlying middle layer (stroma) of the cornea, where microorganisms may penetrate to cause potentially serious infections. Corneal ulcers are among the most common causes of impaired vision and blindness in the world.

Abrasions or scratches typically cause corneal ulcers, which may also result from improper or extended wearing of contact lenses or any other physical stress on the eye. When the cornea is deprived of oxygen due to extended use of contact lenses, infection is more likely. Microorganisms causing infection also may attach to soft contact lenses that are not properly cleaned and disinfected.

Other causes may include viral infections particularly associated with herpes simplex or herpes zoster viruses and bacterial infections linked to contaminated eye drops. Exposure to soil or fungi may also damage eyes. Vitamin A deficiency or protein malnutrition may also cause the condition. Other factors in development of corneal ulcers include use of corticosteroid eye drops, chemical damage, excessive exposure to air or ultraviolet light, or corneal attack by the body's own immune system (autoimmunity). Sexually transmitted diseases (syphilis, chlamydia) might cause corneal ulcers.

Without prompt and proper treatment, corneal ulcers may lead to perforation of the cornea, infection of the eyeball (endophthalmitis), and scarring.

Eye conditions that may make a corneal ulcer more likely include "dry eye" (keratoconjunctivitis sicca), eyelid deformities (entropion, ectropion), diminished sensation in the cornea that may lead to injury, and an increased susceptibility to infection due to a lowered immune system (immunosuppressed state). In rare cases, laser or surgical vision correction procedures (laser-assisted in-situ keratomileusis [LASIK], photorefractive keratectomy [PRK], or radial keratotomy [RK]) have produced corneal ulcers.

Incidence and Prevalence: Contact lenses, especially when worn overnight, are thought to be a major cause of infections leading to corneal ulcers (ulcerative keratitis). Of the approximately 30 million contact lens users in the US ("Focusing"), infection has been reported in about 4.1 per 10,000 daily lens users and 20.9 per 10,000 extended lens users (Donshik).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Individuals dealing with shellfish, such as oyster shuckers, have been found to be susceptible to corneal ulcers because of the presence of specific strains of microorganisms that may infect the eye.

Source: Medical Disability Advisor



Diagnosis

History: Symptoms may include eye pain that worsens with eye or lid movement, severe sensitivity to light (photophobia), blurred or cloudy vision, tearing, and occasionally yellow drainage (pus). There may be a history of eye injury or recent eye disease. The pain may be most obvious when the eyes first open after a period of sleep. Although corneal ulcers are very painful, chronic cases may become less so. Redness may appear in the conjunctiva of the eye. The cornea may start to whiten. In extreme cases, vision may worsen.

Physical exam: An anesthetic eyedrop may be needed to make the eye exam tolerable. If there is pus collecting behind the cornea, a white fluid will be present in the anterior chamber (hypopyon).

Tests: Visual acuity testing will be done to determine the sharpness and discrimination of the individual's vision. A fluorescein dye, instilled on the eye, fills the ulcer (fluorescein staining) and reflects back green light when a fluorescent light is shown on it. The cornea also may be examined by an illuminated microscope or slit lamp (biomicroscopy). If an infection is suspected, an ophthalmologist may remove material from the ulcer by curette and identify the responsible microorganisms (culture). A new laboratory method may directly identify specific genes or DNA sequences of microorganisms responsible for infections (polymerase chain reaction).

Source: Medical Disability Advisor



Treatment

A topical antibiotic ointment or eye drops may be applied to prevent infection. The patient may need protective patches in cases of deeper noninfective penetrations, but patches generally are avoided since oxygen must be allowed to the area to promote healing. A topical anesthetic may be needed to ease pain. Treatment for ulcers caused by infection must begin as soon as possible. Antibiotic medication is typically given by mouth, eye drops, retrobulbar injection, and/or injection into a vein (intravenously) for 4 to 5 days. Underlying conditions that may have caused the ulcer need to be corrected. In some cases, antiviral or antifungal medications may be needed. Noninfectious ulcers that fail to heal may respond to a "bandage" contact lens that protects the area, or to a temporary joining of the eyelids (tarsorrhaphy). A saline lubricating solution may also be needed for moistening. In more severe cases, individuals may need to undergo a corneal transplant (penetrating keratoplasty) to help retain the integrity of the eyeball.

Source: Medical Disability Advisor



Prognosis

Superficial, noninfectious ulcers caused by mechanical injury usually heal quickly. Most uncomplicated cases of corneal ulcers usually resolve completely within several weeks. If the individual did not seek prompt treatment for the condition, an infection or other complications could result in permanent vision loss. More severe corneal ulcers can cause minimal to severe scarring that decreases vision enough to warrant a corneal transplant to restore sight. Depending on the cause, corneal ulcers can recur, especially those caused by herpes simplex or herpes zoster. In extreme cases, the damaged eye may need to be removed (enucleation).

Source: Medical Disability Advisor



Complications

An infected ulcer can cause softening and perforation of the cornea, infection of the entire eye (panophthalmitis), and partial or total loss of visual function. Healing may be slow if the individual is immunosuppressed because of an underlying disease such as rheumatoid arthritis or diabetes mellitus. Corticosteroids used to control inflammation for this or other conditions may decrease healing responses. If the underlying cause is not corrected, ulcers can recur.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Visual acuity should be tested if it is important to the individual's job. Sunlight and ultraviolet light may need to be avoided during the healing process. If the individual experiences permanent vision loss, work station accommodations may be needed such as magnified and high contrast print. Extra illumination may also be required.

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:

  • Does individual have a corneal abrasion or wear contact lenses?
  • Does individual use eye drops that might be contaminated?
  • Has individual had any chemical damage, excessive exposure to air or ultraviolet light, or corneal attack by the body's own immune system (autoimmunity)?
  • Does individual have dry eye syndrome, entropion or ectropion?
  • Is individual's job linked to higher risk?
  • Does individual have diminished sensation in the cornea?
  • Has individual had a laser or surgical vision correction procedure?
  • Does individual complain of eye pain that is worse with eye or lid movement?
  • Does individual have photophobia, blurred or cloudy vision, tearing, or pus?
  • Is there redness in the white of the eye? Has the cornea started to whiten?
  • Was an anesthetic eye drop necessary to make the eye exam tolerable?
  • Is white fluid present in the anterior chamber (hypopyon)?
  • Has the individual had a fluorescein stain, visual acuity test, and/or culture?
  • Have conditions with similar symptoms been ruled out?

Regarding treatment:

  • Is individual being treated with antibiotics or antiviral or antifungal medications?
  • Have underlying conditions been corrected?
  • Was it necessary to use a protective patch and/or artificial tears?
  • Was a "bandage" contact lens used?
  • Was it necessary to temporarily join eyelids (tarsorrhaphy)?

Regarding prognosis:

  • Is individual's employer able to accommodate any necessary restrictions?
  • Does individual have any conditions that may affect ability to recover?
  • Does individual have any complications such as softening and perforation of the cornea, infection of the entire eye, and partial or total loss of vision? Does individual have slow healing secondary to immunosuppression?

Source: Medical Disability Advisor



References

Cited

"Focusing on Treatment." Southwestern. 15 May. 1998. University of Texas Southwestern Medical Center. 16 Dec. 2004 <http://www.swmed.edu/home_pages/publish/magazine/sight/treatment.html>.

Donshik, Peter C. "Extended Wear Revisited." Contact Lens Association of Ophthalmologists, Inc. 16 Dec. 2004 <http://www.clao.org/claoj/cj253/cj253.htm>.

Source: Medical Disability Advisor






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