If the macula of the eye, which is located in the center of the retina, becomes
damaged or stops working it becomes hard to see fine details.
the macula is damaged in an older patient it is known as age-related
macular degeneration and is defined as either wet or dry age-related
macular degeneration. Symptoms for the conditions include gradual
or a rapid loss of the central area of vision. This may include
blurry central vision, black spots in the center of vision, light
sensitivity and colors may seem faded.
Dry age-related macular degeneration is the more common condition.
There are no treatments for this condition, but magnifiers and
reading aids can help patient with loss of vision and small detailed
tasks. Research has found that certain vitamins, antioxidants,
and zinc may slow progression of the disease.
wet age-related macular degeneration, blood vessels begin to grow
behind the retina, leading to bleeding, scarring and possible vision
loss. This condition can develop quickly. If detected in early
stages before scar formation, this condition likely to respond
to some treatments.
Treatments for wet age-related macular degeneration include pharmacological
therapy with intravitreal Lucentis or Avastin injection to target
newly developed abnormal blood vessels, or photodynamic therapy
to break up leaking blood vessels and medications to help slow
formation of new blood vessels.
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Diabetic retinopathy is defined as damage to the blood vessels of retina of
the eye and is associated with long-term diabetes. The retina consists of
a layer of tissue that processes light and images into a series of nerve
signals as they are sent to the brain.
There are two types of this eye condition: non-proliferative diabetic
retinopathy and proliferative diabetic retinopathy. The non-proliferative
condition begins to develop first as blood vessels enlarge in certain
areas, these are known as microaneurysms. This can lead to blocked
blood vessels and small amounts of bleeding or retinal hemorrhages
causing fluid to leak into the retina and vision issues.
Proliferative retinopathy is a more advanced and severe condition.
New blood vessels begin to develop and grow in the eye, but because
they are fragile they can rupture and hemorrhage easily leading
to scaring on the retina and on other parts of the eye resulting
in vision loss and other vision issues. Diabetic retinopathy can
be prevented if blood sugar, blood pressure and cholesterol are
Unfortunately, symptoms of diabetic retinopathy usually are not
noticed until the eye damage is severe. Some symptoms include blurry
vision, gradual vision loss, floaters, problems seeing at night
and areas of shadows obscuring vision.
Those with non-proliferative diabetic retinopathy may not require
treatment. They should be closely monitored by an ophthalmologist
who specializes in treating diabetic retinopathy. Although treatment
cannot reverse damage that has occurred, it is beneficial in helping
the disease from worsening. Patients are also advised to stop smoking.
If new blood vessels begin to grow in the retina, a condition
also known as neovascularization, or if a macular edema forms,
treatment also may be needed. Laser surgical techniques called
photocoagulation can be used to treat the retina, keep blood vessels
from leaking and eliminate fragile blood vessels.
Picture of non-proliferative diabetic retinopathy
Picture of proliferative diabetic retinopathy with some laser
Central Retinal Artery Occlusion (CRAO)
retinal artery occlusion is defined as blockage of the blood
supply in the central artery of the retina (the main trunk of
the artery). Retinal arteries may become blocked by a blood clot
or substances (such as fat or plaque) that get stuck in the arteries.
These blockages may occur due to hardening of the arteries in
the eye. Also, clots may travel from other parts of the body
and block an artery in the retina. A common source of a clot
would be from the carotid artery in the neck or from the heart
lining. Most clots are caused by conditions such as diabetes,
carotid artery disease, high cholesterol, or certain heart rhythm
problem like atrail fibrillaltion.
People with retinal arterial occlusion, whether it is temporary
or permanent, have a risk of stroke because clots may also move
to the brain. Retinal vessel occlusion more often affects older
people. Risk factors are related to the disorders that cause the
blockage. The symptom is a sudden blurring or loss of vision in
the eye. Breathing in (inhaling) a carbon dioxide-oxygen mixture
has been used to treat blockages in the arteries. This treatment
causes the arteries of the retina to widen (dilate). It may allow
the clot to move down the artery and sometimes break up, which
reduces the area of the retina that is affected. The use of the
clot-busting drug, tissue plasminogen activator (tPA), within a
few hours of retinal artery occlusion may be helpful. Unfortunately,
there is no treatment that can consistently restore vision lost
from an artery occlusion. However, if it is caught within the first
hour and treatment is initiated immediately, recovery is possible
in rare cases.
Measures used to prevent other blood vessel (vascular) diseases,
such as coronary artery disease , may decrease the risk of retinal
artery occlusion. These include: eating a low-fat diet ,exercising
,stopping smoking, losing weight if you are overweight. Aspirin
is commonly used to prevent the artery from becoming blocked again.
It is also helpful to control atrial fibrillation.
Branch Retinal Artery Occlusion (BRAO)
central retinal artery, enters the eye through the optic nerve
and divides into multiple branches to perfuse the inner layers
of the retina. A branch retinal artery occlusion (BRAO) occurs
when one of these branches of the arterial supply to the retina
becomes occluded. Most commonly, a branch retinal artery occlusion
occurs secondary to an embolus. Emboli typically originate within
vessels upstream where they dislodge and travel within the circulatory
system to ultimately become lodged downstream in a smaller vessel.
The most common include cholesterol emboli from carotid atheromatous
plaques, platelet-fibrin emboli from thrombotic disease, and
calcific emboli from cardiac valvular disease.
Patients with branch retinal artery occlusion (BRAO) typically
present with sudden, unilateral, painless, partial visual loss.
Risk factors for BRAO include high blood pressure, high cholesterol,
diabetes, coronary artery disease, or history of stroke .
Central Retinal Vein Occlusion (CRVO)
the central retinal artery enter the eye trough the optic nerve,
a central VEIN, LEAVES the eye trough the same area, and can
be occluded too. Veins of the retina can become blocked by a
blood clot. Retinal vein occlusion also can occur when the retinal
arteries put pressure on the retinal vein. This is usually caused
by a condition such as blood clot, Diabetes, Glaucoma, hardening
of the arteries (atherosclerosis), high blood pressure. Painless
visual loss is usually sudden, but it can also occur gradually
over a period of days to weeks.
Due to the lack of oxygen in the retina, there is a risk to develop
new vessels (neovascularization) and then this new vessels creates
an occlusion on the drainage of the aqueous humor that develop
in high pressures in the eye (neovascular glaucoma) or they can
leak into the gel inside the eye (vitreous hemorrhage) There is
no generally accepted medical therapy for occlusion itself. However,
if neovascularization develops,laser treatment of the retina (
pan retinal photocoagulation) should be initiated because it may
decrease vitreous hemorrhages and prevent neovascular glaucoma.
Patients with diagnosis of CRVO should be advised to optimize
systemic disease control.
Branch Retinal Vein Occlusion (BRVO)
of one of the venous branches in the retina is called a branch
retinal vein occlusion (BRVO), and may cause vision loss and
other complications. Males and females are, in general, affected
equally. Most retinal vein occlusions occur after the age of
50, although younger patients are sometimes seen with this disorder.
A major risk factor for branch retinal vein occlusion is atherosclerosis.
Other risk factors include history of stroke, coronary artery
disease, aging, hypertension, elevated blood lipids, smoking,
and glaucoma. Other less common risk factors include blood clotting
abnormalities, infectious diseases, and inflammatory disorders.
The symptoms of a branch retinal vein occlusion depend on which
venous branch is involved. Common symptoms include blurred vision
or changes in a portion of the visual field (peripheral vision).
Occasionally the branch retinal vein occlusion will affect a
vein draining a portion of the retina away from the central vision
and will not cause any symptoms. The complications and treatment
are the same as in the Central Retinal Vein Occlusion.
A floater is a dark, spot, line or shape that moves or drifts throughout the
field of vision. Most people have some floaters and are able to ignore them
unless they are numerous or become more prominent. Floaters are caused when
the vitreous begins to shrink and becomes cobweb-like or stringy, causing
shadows to reflect against the retina.
Floaters develop as a patient ages and usually are merely annoying.
However, floaters can be symptoms of more serious vision issues
such as retinal tears, eye injury, infection, hemorrhaging and
If floaters begin to drastically affect vision, a vitrectomy may
be recommended. During this surgical procedure, the vitreous of
the eye and the floaters are removed and replaced with a salt solution.
However, most surgeons are hesitant to recommend this procedure
because it poses certain risks to the patient’s sight, including
such complications as retinal detachment, retinal tears and cataracts.
Flashes are bursts showers, spots or arcs of light in a patient’s visual
field. If a patient experiences sudden showers of floaters, immediate medical
attention is needed.
The flashes could be caused by the vitreous of the eye pulling
away from the retina or the retina becoming detached from the back
of the eye. Flashes could be short bursts or happen continually
until the retina is repaired. Because visual flashes may be signs
of retinal detachment and can lead to vision loss, immediate medical
care is essential. Flashes and floaters also may indicate vitreous
detachment and other vision issues.
Flashes (photopsia) also can occur after a patient receives a
blow to the head and is sometimes referred to as "seeing stars." Some
patients see flashes of light that look like jagged lines or waves
and last approximately 10 to 20 minutes. These flashes are typically
caused by blood vessel spasm in the brain, which are also called
migraines. When a headache follows these visual flashes, it is
a migraine. If no headache develops, the flashes are called an
ophthalmic or ocular migraine.
Posterior Vitreous Detachment
About 75 percent of patients over the age of 65 experience posterior vitreous
detachment. The condition happens as the vitreous changes and begins to pull
away from the retina.
Symptoms include floaters and flashes of light in vision,
There are no treatments for posterior vitreous detachment. Patients
find that the floaters and flashes subside in about six months.
Over time, they adapt to having floaters in their field of vision
and overall visual acuity remains the same. Very few patients with
posterior vitreous detachment develop the much rarer retinal tearing
or detachment conditions.
Retinal Tears and Retinal Detachments
retinal tear happens when the retina detaches from the back wall
of the eye. If the retina becomes partially detached, blood supply
to the retina is reduced and the ability to process light rays
affected. If the retina is totally detached then the images can
no longer be transmitted between the eye and brain and blindness
When retinal detachment has occurred, a patient’s vision
may seem watery, wavy, shadowed or distorted. In some cases, vision
may be totally lost.
Normally, as people age the vitreous, a clear gel-like fluid that
fills the inner cavity of the eye, begins to decrease and pull
away from the retina. This typically is not harmful to the eye.
In some cases, the vitreous material stays attached the retina,
causing small tears as it shrinks. These peripheral retinal tears
do not affect vision but if left untreated, seepage from the tears
can lead to retinal detachment. Retinal detachments also can be
caused by posterior vitreous detachment, a related disorder, as
well as trauma, diabetes or inflammatory disorders.
Symptoms of retinal tears vary and may not be noticeable. As the
vitreous gel shrinks and pulls away from the retina, flashes of
light may appear in the patient’s vision. Floaters, which
can be visible as black spots or lines, can be the result of retina
vessels bleeding or from the formation of small areas of vitreous
matter. Floaters and flashes may not necessarily indicate a retinal
tear, patients should be examined to be sure.
Immediate treatment is needed for retinal tears to prevent the
retina from detaching and a loss of vision. Surgical treatments
focus on creating a scar that helps to bond the retina to the back
of the eye. These treatments are done with laser light or freezing
methods. More than 90% of retina detachments can be repaired, preventing
further loss of sight and possibly restoring sight.
Cystoid Macular Edema (CME)
Cystoid macular edema, commonly called CME, is a painless disorder which affects
the central retina or macula. The eye is often compared to a camera, with
the front of the eye containing the lens that focuses images on the inside
back layer of the eye; this back layer is called the retina, and it is covered
with special nerve cells that react to light. When CME is present, multiple
cyst-like (cystoid) areas of fluid appear in the macula and cause retinal
swelling or edema. This swelling in the retina in turn can cause decreased
Some causes of CME include:
Eye surgery, including cataract surgery
A stroke in the eye causing blockage in the small arteries
or veins of the retina (branch or central retina vein occlusion)
Inflammation of the eye
The first symptom of CME is blurry or "wavy" vision
in the center of your visual field. Your Eye M.D. can make this
diagnosis by carefully examing the eye and also doing a special
scan of the back of the eye, called an Ocular Coherence Tomography
Only your Eye M.D. can recommend the right treatment for CME.
Treatment options vary depending on the degree of retinal swelling,
but some options include: eye drops, injections of steroids or
other medications inside or around the eye, and possibly surgery.
No matter what the cause of the CME, it usually takes several
months for it to go away. The patient should not get discouraged.
It is important that you keep following your Eye M.D.'s recommendations.
retinopathy is damage to the retina from high blood pressure.
High blood pressure can damage blood vessels in the retina. The
higher the blood pressure and the longer it has been high, the
more severe the damage is likely to be. When you have diabetes,
high cholesterol levels, or you smoke, you have a higher risk
of damage and vision loss. Most people with hypertensive retinopathy
do not have symptoms until late in the disease. Malignant hypertension
may cause the following sudden symptoms, and should be considered
a medical emergency. The symptoms include double vision or dim
vision, headaches, and/or visual disturbances and sometimes sudden
The degree of retina damage (retinopathy) is graded on a scale
of 1 to 4:
At grade 1, you may not have symptoms.
In between grades 1 and 4, there are a number of changes in
the blood vessels, areas where blood vessels have leaked, and
other parts of the retina.
Grade 4 hypertensive retinopathy includes swelling of the optic
nerve and of the visual center of the retina (macula). This swelling
can cause decreased vision.
Controlling high blood pressure (hypertension) is the only treatment
for hypertensive retinopathy. Patients with grade 4 (severe hypertensive
retinopathy) often have heart and kidney complications of high
blood pressure. They are also at higher risk for stroke. The retina
will generally recover if the blood pressure is controlled. However,
some patients with grade 4 hypertensive retinopathy will have permanent
damage to the optic nerve or macula.
Controlling high blood pressure prevents changes in the blood
vessels of the eye, as well as in other organs like the heart,
kidneys, and brain.
Epiretinal Membrane (ERM)
membrane is a translucent or semitranslucent fibrocellular tissue
formed on the surface of the retina in response to changes in
the vitreous humor. It can be associated with a wide variety
of conditions, including retinal vascular occlusions, uveitis,
trauma, intraocular surgery, and retinal breaks. Majority of
the time, there is no known cause. Both sexes are equally affected.
Contracture of ERMs produces distortion and wrinkling of the inner
surface of the retina, also called cellophane maculopathy or macular
pucker in severe cases.
Affected patients may be asymptomatic, or they may present with
symptoms of distortion, decreased image size from the affected
eye causing double vision, or swelling of the macula causing decreased
The definite treatment for severe cases of ERMs is vitrectomy
with membrane peel. Surgery is not usually recommend unless the
distortions or decreased vision are severe enough to interfere
with daily living, since there are the usual hazards of surgery,
infections, and a possibility of retinal detachment.
macular hole is defined as a small hole in the macula, the area
of the eye that is responsible for the sharp, detailed vision
needed for reading, driving and small detail work. This condition
is more common in patients ages 60 and older.
Symptoms of a macular hole include problems with the central area
of vision. For example, straight lines may appear wavy and reading
may be difficult. In later stages, there may be small blank areas
in the central vision.
In some cases, macular holes close up by themselves. Other cases
require a vitrectomy, a surgical procedure to remove some of the
vitreous gel from the interior of the eye to prevent pulling on
the retina. The removed gel is replaced with a bubble containing
a combination of air and gas. This bubble acts as an internal bandage
as the macular hole heals and reseals itself.
Optical coherence tomography picture of Macular Hole