American Medical Association Family Medical Guide - American Medical Association [729]
Diagnosis and Treatment
A diagnosis of astigmatism is based on the symptoms, an eye examination, and the results of vision tests.
Mild astigmatism usually does not need to be corrected. To correct more severe astigmatism and enable a person to see clearly, a doctor prescribes glasses or contact lenses that are shaped to the curvature of the cornea. The shape compensates for the unevenness of the surface of the cornea. In some cases, ophthalmologists recommend LASIK (see page 1030) to correct astigmatism.
Disorders of the Eyelids
The eyelids are movable folds of skin that cover and protect the visible surface of the eye. Muscles in the eyelids open and close them and work with fibrous and elastic tissue in the eyelids to keep them snug against the eyeball. A row of small glands, called meibomian glands, lubricates the edges of the eyelids. Rows of hairs (eyelashes), which also help protect the eye, grow from tiny pits called follicles at the edges of both the upper and lower eyelids.
Ptosis
Ptosis is a condition in which the upper eyelid droops and partially or completely covers the eye. Ptosis may be congenital (present from birth) and can run in families. However, it also can occur in anyone at any age if the nerve that controls the eyelid muscle or the muscle itself is damaged. The nerve can be damaged by an injury, an underlying disease such as diabetes (see page 889), or a brain tumor (see page 682). The muscle can be weakened as a result of muscular dystrophy (see page 972) or myasthenia gravis (see page 701) or as a natural result of aging. Ptosis may affect one or both eyes and may vary in severity over the course of each day.
Symptoms
Severe ptosis can prevent a person from seeing out of the affected eye. If ptosis is caused by a brain tumor, the person may have double vision.
Ptosis
In ptosis, the upper eyelid droops and partially or completely covers the eye. In some cases, this condition may result from diabetes or a brain tumor, or it may be a symptom of a muscle or nerve disorder such as muscular dystrophy or myasthenia gravis.
Diagnosis and Treatment
A diagnosis of ptosis is based on the symptoms and an examination of the eye and eyelid. Ptosis usually improves after successful treatment of any underlying disease. In people whose vision is impaired as a result of ptosis, surgery can be performed to raise the drooping eyelid.
Stye
Like all hairs, eyelashes grow from tiny pits in the skin called follicles. When a follicle on the eyelid becomes infected, a swelling called a stye develops on the edge of the eyelid around the base of the eyelash (see page 128).
Stye
A red, painful swelling called a stye can develop on the edge of the eyelid when a hair follicle becomes infected. Styes often recur, and several may develop on the eyelid at the same time.
Symptoms
A stye is usually red and is often painful, especially when touched. Gradually, a white head of pus appears on the swelling. Several styes may develop at the same time if the bacteria that are causing the infection spread to other follicles. A stye usually bursts and drains within a few days after it forms, relieving the pain. The swelling usually subsides after about a week.
Treatment
To help a stye drain earlier, apply frequent warm, moist compresses as soon as it appears, to help draw the pus to a head. Do not squeeze the stye—allow it to open and release the pus on its own. Afterward, wash the eyelid carefully with mild soap or baby shampoo, using a clean, soft washcloth to remove all of the pus. Be careful not to spread the infection.
If a stye does not clear up in a week or so, if the swelling, redness, or tenderness spreads, or if a stye recurs, see your doctor. He or she will examine you, perform tests to determine what type of bacterium is causing the infection, and prescribe an antibiotic to treat the infection.
Chalazion
A chalazion is a painless swelling on the edge of the eyelid