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Read more about some common eye conditions below
- Blepharitis: A common inflammatory condition
that affects the eyelids. It usually causes burning,
itching and irritation of the lids. In severe cases,
it may also cause styes, irritation and inflammation
of the cornea (keratitis) and conjunctiva (conjunctivitis).
Some patients have no symptoms at all. It is usually
a chronic problem that can be controlled with extra
attention to lid hygiene. However, it is sometimes
caused by an infection and may require medication.
- Branch Retinal Vein Occlusion: Branch and
central retinal vein occlusion occurs when the circulation
of a retinal vein becomes obstructed by an adjacent
blood vessel, causing hemorrhages in the retina. Swelling
and ischemia (lack of oxygen) of the retina as well
as glaucoma are fairly common complications. The visual
symptoms can vary in severity from one person to the
next, and are dependent on whether the central retinal
vein or a branch retinal vein is involved. Patients
who experience a branch vein occlusion often notice
a gradual improvement in their vision as the hemorrhage
resolves. Recovery from a central vein occlusion is
much less likely since it affects the macula. This
problem appears equally in males and females and is
more common after the age of 60.
- Cataracts: A clouding of the natural lens,
the part of the eye responsible for focusing light
and producing clear, sharp images. The lens is contained
in a sealed bag or capsule. As old cells die they
become trapped within the capsule. Over time, the
cells accumulate causing the lens to cloud, making
images look blurred or fuzzy. For most people, cataracts
are a natural result of aging
- Central Retinal Vein Occlusion: (See Branch
Retinal Vein Occlusion)
- Conjunctivitis: commonly known as pink eye,
is an infection of the conjunctiva (the outer-most
layer of the eye that covers the sclera). The three
most common types of conjunctivitis are: viral, allergic,
and bacterial. Each requires different treatments.
With the exception of the allergic type, conjunctivitis
is typically contagious.
- Corneal Ulcer: May form when the surface
of the cornea is damaged or compromised. Ulcers may
be sterile (no infecting organisms) or infectious.
The term infiltrate is also commonly used along with
ulcer. Infiltrate refers to an immune response causing
an accumulation of cells or fluid in an area of the
body where they don't normally belong. Whether or
not an ulcer is infectious is an important distinction
for the doctor to make and determines the course of
treatment. Bacterial ulcers tend to be extremely painful
and are typically associated with a break in the epithelium,
the superficial layer of the cornea. In some cases,
the inflammatory response involves the anterior chamber
along with the cornea. Certain types of bacteria,
such as Pseudomonas, are extremely aggressive and
can cause severe damage and even blindness within
24-48 hours if left untreated.
- Diabetic Retinopathy: People with diabetes
are more likely to develop eye problems such as cataracts
and glaucoma, but the disease's affect on the retina
is the main threat to vision. Most patients develop
diabetic changes in the retina after approximately
20 years. The effect of diabetes on the eye is called
diabetic retinopathy. Over time, diabetes affects
the circulatory system of the retina. The earliest
phase of the disease is known as background diabetic
retinopathy. In this phase, the arteries in the retina
become weakened and leak, forming small, dot-like
hemorrhages. These leaking vessels often lead to swelling
or edema in the retina and decreased vision. The next
stage is known as proliferative diabetic retinopathy.
In this stage, circulation problems cause areas of
the retina to become oxygen-deprived or ischemic.
New, fragile, vessels develop as the circulatory system
attempts to maintain adequate oxygen levels within
the retina. This is called neovascularization. Unfortunately,
these delicate vessels hemorrhage easily.
- Dry Eye Syndrome is very common. It is usually
caused by a problem with the quality of the tear film
that lubricates the eyes. One of the most common reasons
for dryness is simply the normal aging process. As
we grow older, our bodies produce less oil - 60% less
at age 65 than at age 18. This is more pronounced
in women, who tend to have drier skin than men. The
oil deficiency also affects the tear film. Without
as much oil to seal the watery layer, the tear film
evaporates much faster, leaving dry areas on the cornea.
Many other factors, such as hot, dry or windy climates,
high altitudes, air-conditioning and cigarette smoke
also cause dry eyes. Many people also find their eyes
become irritated when reading or working on a computer.
Stopping periodically to rest and blink keeps the
eyes more comfortable. Contact lens wearers may also
suffer from dryness because the contacts absorb the
tear film, causing proteins to form on the surface
of the lens. Certain medications, thyroid conditions,
vitamin A deficiency, and diseases such as Parkinson's
and Sjogren's can also cause dryness. Women frequently
experience problems with dry eyes as they enter menopause
because of hormonal changes.
- Ectropion is a sagging lower eyelid that
leaves the eye exposed and dry. It is caused by a
lack of tone of the delicate muscles that hold the
lid taut against the eye. Excessive tearing is common
with ectropion, but wiping the tears away only causes
the lid to sag more. Ectropion is most common among
people over the age of 60.
- Entropion: An eyelid that turns inward, is
a problem that typically affects the lower lid. It
usually stems from a muscle spasm; however, it can
also be caused by scarring from trauma or inflammation
from certain diseases that involve the eyelids. When
the eyelid turns inward, the lashes rub against the
eye, resulting in irritation, scratchiness, tearing
and redness. Surgery is often required to correct
the problem.
- Episcleritis: an inflammatory condition of
the connective tissue between the conjunctiva and
sclera known as the episclera. The eye's red appearance
makes it look similar to conjunctivitis, or pink eye,
but there is no discharge or tearing. It usually has
no apparent cause; however, it is sometimes associated
with systemic inflammatory conditions such as arthritis,
lupus, and inflammatory bowel disease. Rosacea, herpes
simplex, gout, tuberculosis, and other diseases are
also occasionally underlying causes. Women are typically
affected by episcleritis more frequently than men.
It characteristically occurs in people who are in
their 30's and 40's and is often a recurrent problem.
- Floaters & Flashes: The space between
the crystalline lens and the retina is filled with
a clear, gel-like substance called vitreous. With
age, the vitreous thins and may separate from the
back of the eye. This is called posterior, a very
common, usually harmless condition. As the vitreous
pulls free from the retina, it is often accompanied
by light flashes or floaters. Floaters are caused
by tiny bits of vitreous gel or cells that cast shadows
on the retina. Flashes occur when the vitreous tugs
on the sensitive retina tissue. There are other more
serious causes of flashes and floaters, however. Retinal
tears, retinal detachment, infection, inflammation,
hemorrhage, or an injury such as a blow to the head
may also cause floaters and flashes. (Have you ever
seen stars after bumping your head?) Occasionally,
flashes of light are caused by neurological problems
such as a migraine headache. When related to a headache,
the flashes of light are seen in both eyes and usually
last 20-30 minutes before the headache starts.
- Glaucoma is a disease caused by increased
intraocular pressure (IOP) resulting either from a
malformation or malfunction of the eye's drainage
structures. Left untreated, an elevated IOP causes
irreversible damage the optic nerve and retinal fibers
resulting in a progressive, permanent loss of vision.
However, early detection and treatment can slow, or
even halt the progression of the disease. The eye
constantly produces aqueous, the clear fluid that
fills the anterior chamber (the space between the
cornea and iris). The aqueous filters out of the anterior
chamber through a complex drainage system. The delicate
balance between the production and drainage of aqueous
determines the eye's intraocular pressure (IOP). Most
people's IOPs fall between 8 and 21. However, some
eyes can tolerate higher pressures than others. That's
why it may be normal for one person to have a higher
pressure than another.
- Keratitis is a term used to define a wide
variety of corneal infections, irritations, and inflammations;
since each type of condition is unique, medical diagnosis
and treatment is essential. Corneal ulcers are commonly
caused by bacterial or fungal invasions following
superficial corneal abrasions; among the common infectious
agents are: staphyloccus, streptococcus, herpes (both
simplex and zoster), adenovirus, rubeola, rubella,
mumps, trachoma, infectious mononucleosis, and pneumococcus;
also at fault may be Vitamin A deficiency or broad
spectrum antibiotic drug reactions. Corneal ulcers
may also follow trauma, may be associated with other
eye infections (e.g., conjunctivitis), may be related
to other corneal disorders (e.g., degenerative conditions,
or ptosis, which may cause a "dry eye"),
or may arise from a variety of systemic disorders
(especially those of autoimmune origin). Symptoms
of corneal infection include extreme pain and photophobia.
- Keratoconus is a degenerative disease of
the cornea that causes it to gradually thin and bulge
into a cone-like shape. This shape prevents light
from focusing precisely on the macula. As the disease
progresses, the cone becomes more pronounced, causing
vision to become blurred and distorted. Because of
the cornea's irregular shape, patients with keratoconus
are usually very short sighted and have a high degree
of astigmatism that is not correctable with glasses.
- Macular Degeneration is a degenerative condition
of the macula (the central retina) and its prevalence
increases with age. Age Related Macular Degeneration
ARMD is caused by hardening of the arteries that nourishes
the retina. This deprives the sensitive retinal tissue
of oxygen and nutrients that it needs to function
and thrive. As a result, the central vision deteriorates.
Macular degeneration varies widely in severity. In
the worst cases, it causes a complete loss of central
vision, making reading or driving impossible. For
others, it may only cause slight distortion. Fortunately,
macular degeneration does not cause total blindness
since it does not affect the peripheral vision.
- Pinguecula (pin gwe' cue la) is a benign,
yellowish growth that forms on the conjunctiva. They
usually grow near the cornea on the nasal side. Pingueculae
(plural form of pinguecula) are thought to be caused
by ultraviolet light and are most common among people
who spend a great deal of time outdoors. This growth
does not affect vision, but may cause irritation if
it becomes elevated. In rare cases, the pinguecula
may gradually extend over the cornea, forming a pterygium.
- Pterygium is a raised, wedge-shaped growth
of the conjunctiva. It is most common among those
who live in tropical climates or spend a lot of time
in the sun. Symptoms may include irritation, redness,
and tearing. Pterygiums are nourished by tiny capillaries
that supply blood to the tissue. For some, the growth
remains dormant; however, in other cases it grows
over the central cornea and affects the vision. As
the pterygium develops, it may alter the shape of
the cornea, causing astigmatism. If the pterygium
invades the central cornea, it is removed surgically.
Since pterygiums are most commonly caused by sun exposure,
protecting the eyes from sun, dust and wind is recommended.
Instilling artificial tears liberally is also helpful
to decrease irritation. In some cases, steroid drops
are prescribed to reduce inflammation.
- Retinal Detachment occurs when the retina's
sensory and pigment layers separate. Because it can
cause devastating damage to the vision if left untreated,
retinal detachment is considered an ocular emergency
that requires immediate medical attention and surgery.
It is a problem that occurs most frequently in the
middle-aged and elderly. There are three types of
retinal detachments. The most common type occurs when
there is a break in the sensory layer of the retina,
and fluid seeps underneath, causing the layers of
the retina to separate. Those who are very short sighted,
have undergone eye surgery, or have experienced a
serious eye injury are at greater risk for this type
of detachment. Nearsighted people are more susceptible
because their eyes are longer than average from front
to back, causing the retina to be thinner and more
fragile. The second most common type occurs when strands
of vitreous or scar tissue create traction on the
retina, pulling it loose. Patients with diabetes are
more likely to experience this type. The third type
happens when fluid collects underneath the layers
of the retina, causing it to separate from the back
wall of the eye. This type usually occurs in conjunction
with another disease affecting the eye that causes
swelling or bleeding.
- Subconjunctival Haemorrhage occurs when a
small blood vessel under the conjunctiva breaks and
bleeds. It may occur spontaneously or from coughing,
heavy lifting, or vomiting. In some cases, it may
develop following eye surgery or trauma. Subconjunctival
hemorrhage tends to be more common among those with
diabetes and hypertension. While it may look frightening,
a subconjunctival hemorrhage is essentially harmless.
The blood becomes trapped underneath the clear conjunctival
tissue, much like a bruise. The blood is visible because
it shows through the thin, clear conjunctiva. The
blood naturally absorbs within one to three weeks
and no treatment is required.
- Vitreous Detachment: The space between the
crystalline lens and the retina is filled with a clear,
gel-like substance called vitreous. With age, the
vitreous thins and may separate from the back of the
eye. This is called posterior vitreous detachment
(PVD), a very common, usually harmless condition.
(See also Flashes and Floaters)
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National Eye Institute,
National Institutes of Health |
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