Categories
Ailmemts & Remedies

Retinal Detachment

Definition:
Retinal detachment is a disorder of the eye in whose the retina peels away from its underlying layer of support tissue. Initial detachment may be localized, but without rapid treatment the entire retina may detach, leading to vision loss and blindness.  It is a separation of the light-sensitive membrane in the back of the eye (the retina) from its supporting layers.It is a medical emergency.

CLICK & SEE

The retina is a thin layer of light sensitive tissue on the back wall of the eye. The optical system of the eye focuses light on the retina much like light is focused on the film in a camera. The retina translates that focused image into neural impulses and sends them to the brain via the optic nerve. Occasionally, posterior vitreous detachment, injury or trauma to the eye or head may cause a small tear in the retina. The tear allows vitreous fluid to seep through it under the retina, and peel it away like a bubble in wallpaper.

Types
*Rhegmatogenous retinal detachment – A rhegmatogenous retinal detachment occurs due to a hole, tear, or break in the retina that allows fluid to pass from the vitreous space into the subretinal space between the sensory retina and the retinal pigment epithelium.

*Exudative, serous, or secondary retinal detachment – An exudative retinal detachment occurs due to inflammation, injury or vascular abnormalities that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break.

*Tractional retinal detachment – A tractional retinal detachment occurs when fibrovascular tissue, caused by an injury, inflammation or neovascularization, pulls the sensory retina from the retinal pigment epithelium.

A substantial number of retinal detachments result from trauma, including blunt blows to the orbit, penetrating trauma, and concussions to the head. A retrospective Indian study of more than 500 cases of rhegmatogenous detachments found that 11% were due to trauma, and that gradual onset was the norm, with over 50% presenting more than one month after the inciting injury.

You may Click to see :-
Age-Related Macular Degeneration

Symptoms:
A retinal detachment is commonly preceded by a posterior vitreous detachment which gives rise to these symptoms:

*bright flashes of light, especially in peripheral vision (photopsia) – very brief in the extreme peripheral (outside of center) part of vision
*a sudden dramatic increase in the number of floaters
*a ring of floaters or hairs just to the temporal side of the central vision
*a slight feeling of heaviness in the eye
*blurred vision
*hadow or blindness in a part of the visual field of one eye

Although most posterior vitreous detachments do not progress to retinal detachments, those that do produce the following symptoms:

*a dense shadow that starts in the peripheral vision and slowly progresses towards the central vision
*the impression that a veil or curtain was drawn over the field of vision
*straight lines (scale, edge of the wall, road, etc.) that suddenly appear curved (positive Amsler grid test)
*central visual loss

(None of this is to be confused with the broken retina which is generally the tearing of muscle and nerve behind the eye)

Causes, Incidence, And Risk Factors
The retina is a transparent tissue in the back of the eye. It helps you see the images that are focused on it by the cornea and the lens. Retinal detachments are often associated with a tear or hole in the retina through which eye fluids may leak. This causes separation of the retina from the underlying tissues.

Retinal detachment often occurs on its own without an underlying cause. However, it may also be caused by trauma, diabetes, an inflammatory disorder. It is most often caused by a related condition called posterior vitreous detachment.

Diagnosis:
Signs And Tests:-
Tests will be done to check the retina and pupil response and your ability to see colors properly. These may include:

*Electroretinogram (a record of the electrical currents in the retina produced by visual stimuli)
*Fluorescein angiography
*Intraocular pressure determination
**Refraction test
*Retinal photography
*Test to determine your ability to see colors properly (color defectiveness)
*Visual acuity
*Slit-lamp examination
*Ultrasound of the eye

Treatment of Rhegmatogenous Retinal Detachment:
There are several methods of treating a detached retina which all depend on finding and closing the breaks which have formed in the retina. All three of the procedures follow the same 3 general principles:

1.Find all retinal breaks
2.Seal all retinal breaks
3.Relieve present (and future) vitreoretinal traction

Cryopexy and Laser Photocoagulation:
Cryotherapy (freezing) or laser photocoagulation are occasionally used alone to wall off a small area of retinal detachment so that the detachment does not spread.

Scleral buckle surgery:
Scleral buckle surgery is an established treatment in which the eye surgeon sews one or more silicone bands (bands, tyres) to the sclera (the white outer coat of the eyeball). The bands push the wall of the eye inward against the retinal hole, closing the break or reducing fluid flow through it and reducing the effect of vitreous traction thereby allowing the retina to re-attach. Cryotherapy (freezing) is applied around retinal breaks prior to placing the buckle. Often subretinal fluid is drained as part of the buckling procedure. The buckle remains in situ. The most common side effect of a scleral operation is myopic shift. That is, the operated eye will be more short sighted after the operation. Radial scleral buckle is indicated to U-shaped tears or Fishmouth tears and posterior breaks. Circumferential scleral buckle indicated to multiple breaks, anterior breaks and wide breaks. Encircling buckles indicated to breaks more than 2 quadrant of retinal area, lattice degeration located on more than 2 quadrant of retinal area, undetectable breaks, and proliferative vitreous retinopathy.

Pneumatic retinopexy:
This operation is generally performed in the doctor’s office under local anesthesia. It is another method of repairing a retinal detachment in which a gas bubble (SF6 or C3F8 gas) is injected into the eye after which laser or freezing treatment is applied to the retinal hole. The patient’s head is then positioned so that the bubble rests against the retinal hole. Patients may have to keep their heads tilted for several days to keep the gas bubble in contact with the retinal hole. The surface tension of the air/water interface seals the hole in the retina, and allows the retinal pigment epithelium to pump the subretinal space dry and suck the retina back into place. This strict positioning requirement makes the treatment of the retinal holes and detachments that occurs in the lower part of the eyeball impractical. This procedure is usually combined with cryopexy or laser photocoagulation.

Vitrectomy:
Vitrectomy is an increasingly used treatment for retinal detachment. It involves the removal of the vitreous gel and is usually combined with filling the eye with either a gas bubble (SF6 or C3F8 gas) or silicon oil. Advantages of using gas in this operation is that there is no myopic shift after the operation and gas is absorbed within a few weeks. Silicon oil (PDMS), if filled needs to removed after a period of 2–8 months depending on surgeon’s preference. Silicon oil is more commonly used in cases associated with proliferative vitreo-retinopathy (PVR). A disadvantage is that a vitrectomy always leads to more rapid progression of a cataract in the operated eye. In many places vitrectomy is the most commonly performed operation for the treatment of retinal detachment.

Results of Surgery:
85 percent of cases will be successfully treated with one operation with the remaining 15 percent requiring 2 or more operations. After treatment patients gradually regain their vision over a period of a few weeks, although the visual acuity may not be as good as it was prior to the detachment, particularly if the macula was involved in the area of the detachment. However, if left untreated, total blindness could occur in a matter of days.

You may click to see :

Retinal Detachment Repair Images

Prevention:
Retinal detachment can sometimes be prevented. The most effective means is by educating people to seek ophthalmic medical attention if they suffer symptoms suggestive of a posterior vitreous detachment.  Early examination allows detection of retinal tears which can be treated with laser or cryotherapy. This reduces the risk of retinal detachment in those who have tears from around 1:3 to 1:20.

There are some known risk factors for retinal detachment. There are also many activities which at one time or another have been forbidden to those at risk of retinal detachment, with varying degrees of evidence supporting the restrictions.

Cataract surgery is a major cause, and can result in detachment even a long time after the operation. The risk is increased if there are complications during cataract surgery, but remains even in apparently uncomplicated surgery. The increasing rates of cataract surgery, and decreasing age at cataract surgery, inevitably lead to an increased incidence of retinal detachment.

Trauma is a less frequent cause. Activities which can cause direct trauma to the eye (boxing, kickboxing, karate, etc.) may cause a particular type of retinal tear called a retinal dialysis. This type of tear can be detected and treated before it develops into a retinal detachment. For this reason governing bodies in some of these sports require regular eye examination.

Individuals prone to retinal detachment due to a high level of myopia are encouraged to avoid activities where there is a risk of shock to the head or eyes, although without direct trauma to the eye the evidence base for this may be unconvincing.   Some doctors recommend avoiding activities that increase pressure in the eye, including diving, skydiving, again with little supporting evidence. According to one medical website, retinal detachment does not happen as a result of straining your eyes, bending or, heavy lifting. Roller coasters and other activities that could cause trauma should be avoided for those who have had a family history of retinal detachment,but those who are at low risk because of nearsightedness should be alright, just nothing extreme like skydiving, bungee jumping etc., but those who have had cataract surgery should not participate in thrill rides or any activity that could cause trauma to the head or eyes. In order to cause retinal detachment for those at a low risk, one must hit the head extremely hard like a car accident for instance. For those at high risk, activities that have nothing to do with the head or eyes would be alright. Therefore, heavy weightlifting would appear to be fine. However, two recent scientific articles    have noted cases of retinal detachment or maculopathy due to weightlifting (specifically with the Valsalva method), and a third documented an increase in blood pressure in the eye during weightlifting  . Moreover, a recent case-control study focusing on myopic subjects supports the hypothesis that occupational heavy lifting (or manual handling) requiring Valsalva maneuver may be a risk factor for retinal detachment .

Activities that involve sudden acceleration or deceleration also increase eye pressure and are discouraged by some doctors. These include bungee jumping  and drag racing.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.righthealth.com/topic/Retinal_Detachment/overview/adam20?fdid=Adamv2_001027&section=Full_Article
http://en.wikipedia.org/wiki/Retinal_detachment

http://www.netheryeye.com/OurServices/RetinalDetachment.aspx

Retinal Detachment Eye Surgery Done On My Right Eye

Enhanced by Zemanta
Advertisements
Categories
Diagnonistic Test

Fluorescein Angiography (Test for Diabetic Retinopathy)

[amazon_link asins=’935090991X,9350255774,1560550090,0801653886,3540783598,8180611965,3540300600,1560550449,0750670010′ template=’ProductCarousel’ store=’finmeacur-20′ marketplace=’US’ link_id=’f80df6c0-62ca-11e7-b25e-9358514e523c’]

Alternative Names: Retinal photography; Eye angiography

Definition:
Fluorescein angiography is an eye test that uses an special dye and camera to look at blood flow in the retina and choroid……...CLICK & SEE

By looking into the back of your eye (the retina), eye doctors can see changes in the blood vessels there that show whether you are at risk for losing vision from diabetes or other causes. The earliest changes can be seen only with a special test called fluorescein angiography. For this test, a chemical that temporarily makes the blood vessels fluorescent and shows very tiny leaks in them is injected into one of your arm or hand veins while you are having your eyes examined.

This test is used to determine if there is proper circulation in the blood vessels of the retina. It can also be used to diagnose problems in the eye or to determine how well treatment is working.

Preparation  for the test:
You should arrange to have someone else drive you home from the eye doctor, because your eyes will be dilated; this can make your eyes sensitive to the sun and your vision blurry for a while.

You may be told to discontinue drugs that could affect the test. results. Tell your health care provide about any allergies, particularly reactions to iodine.

You must sign an informed consent form. You must remove contact lenses before the test.

Tell the health care provider if you may be pregnant.


How the Test Is Performed

Eye drops that make the pupil dilate will be given. You will be asked to place your chin on a chin rest, and your forehead against a support bar to keep your head still during the test.

Fluorescein angiography->…..CLICK & SEE

The health care provider will take pictures of the inside of your eye. After the first group of pictures are taken, a special dye called fluorescein is injected into your vein, usually at the bend of the elbow. A special camera takes pictures of the dye as it moves through the blood vessels in the back of the eye.

More photographs are taken up to 20 minutes after the injection.

What happens when the test is performed?
You have drops put into your eye to make the pupil dilate (open), and you have to wait for about half an hour while the drops take effect. Before giving you any other medicine, your doctor might first examine your eyes for signs of bleeding or debris outside of your retina arteries; these are signs of more advanced eye disease from diabetes. Then a nurse inserts a small needle into one of the veins in your arm or hand so that you can have a dose of medicine injected. Your doctor uses a special eye camera to take pictures of your retina. You look into one side of the camera while your doctor looks through the other side. The camera shines a dim blue light into your eye, which causes the dye flowing through the retina arteries to show up as fluorescent green. The doctor takes a collection of pictures of your eyes to review more closely later.

This color retinal photograph demonstrates nonproliferative diabetic retinopathy. The image is centered on the macula (the part of the retina responsible for central fine vision) with part of the optic nerve seen on the left of the photo (left eye). There are hemorrhages within the retinal tissue on the right side of the photograph.

How the Test Will Feel
When the needle is inserted , some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

When the dye is injected, you may have mild nausea and a warm sensation. These symptoms are usually very brief.

Normal Results:
A normal result means the vessels appear a normal size and there are no blockages or leakages.
Back to TopWhat Abnormal Results Mean
If blockage or leakage is present, the pictures will map the location for possible treatment.

An abnormal value on a fluorescein angiography may be due to:

*Blood flow (circulatory) problems
*Cancer
*Diabetic or other retinopathy
*Inflammation or edema
*Macular degeneration
*Microaneurysms — enlargement of capillaries in the retina
*Tumors
*Swelling of the optic disc

Additional conditions under which the test may be performed:

Retinal detachment
Retinal vessel occlusion
Retinitis pigmentosa

Risk Factors:
There are no special risks from this test, although your vision may be blurry for an hour or more after the test because your pupils are dilated. The dye fluorescein is excreted from your body in your urine, which might give your urine a bright or discolored appearance for a day.

There is a slight chance of infection any time the skin is broken. Rarely, a person is hypersensitive to the dye and may experience:

*Dizziness or faintness
*Dry mouth or increased salivation
*Hives
*Increased heart rate
*Metallic taste in mouth
*Nausea and vomiting
*Sneezing
*Serious allergic reactions are rare.

Your urine will be darker, and possibly orange in color, for a day or two after the test.

Must you do  after the test is over?

You will need to wear sunglasses for a few hours until your pupils are no longer dilated.

Considerations:
People with cataracts will have less accurate test results.

How long is it before the result of the test is known?
Your doctor can often discuss the results of the test with you at the end of your visit. He or she might recommend treatment (such as eye laser treatments) if your test reveals retina disease.

Click to see:->How does diabetes affect the retina?

Resources:
https://www.health.harvard.edu/diagnostic-tests/fluorescein-angiography.htm
http://health.nytimes.com/health/guides/test/fluorescein-angiography/overview.html

Reblog this post [with Zemanta]