The Eye...
The eye is like a camera. When you take a picture the lens in the front of the camera allows light through and focuses that light on the film that covers the back inside wall of the camera. When the light hits the film, a picture is taken.
The eye works in much the same way. The front parts of the eye (cornea, pupil and lens) are clear and allow light to pass through. The light is then focused on a thin layer of tissue called retina, which covers the back inside wall of the eye.
The Retina...
The retina is like the film in a camera. It is the seeing tissue of the eye. When the focused light hits the retina, a picture is taken. Messages about these pictures are sent to the brain through the optic nerve (the nerve of the eye), and this is how we see.
The retina has two parts: the peripheral retina and the central macula.
Macula lies in the central part of the retina. This is the only part of the retina capable of producing sharp and crisp image. Sharp and crisp image enables us to read, write, watch Television and drive.
What Is Age related Macular Degeneration...
Age-related macular degeneration (ARMD) is the most common cause of irreversible vision loss in people over age of 60 years. Aging causes the cells in the macula to become less efficient.
There are two main types of macular degeneration, "dry" and "wet," which are discussed in the next section.
Dry type of Age related Macular degeneration...
The round deposits called drusen (degenerated material) appear beneath the retina . A few small drusen cause no decrease in vision. However, if many large drusen develop, vision may be decreased.
The dry type of macular degeneration presents with a slow, progressive loss of vision. In this type the vision remains stable and good for a longer period of time.
Macular degeneration at later stage
Drusen
.
Wet type of Age related Macular degeneration :
In this type, abnormal blood vessels grow beneath the macula, they leak and bleed.
The "wet" form of macular degeneration can cause more severe visual loss. Vision may suddenly become distorted or blurred.
Causes of Macular degeneration :
Genetic, Age, Smoking may play a role.
Symptoms of Macular degeneration:
1. Initially patient may complain of seeing wavy or crooked lines or images.
2. Later on patient may have loss of central part of vision (may be slow with dry type and sudden in wet type of Age related macular degeneration).
3. Difficulty in reading, writing,watching TV.
How to diagnose Age related Macular degeneration :
AMD is diagnosed by:
1. A through eye examination.
2. Specialized test like FFA (Fluorescein Angiography) and OCT (Ocular Coherence Tomography) .
Eye Examinations:
Today's advances in medicine mean that more and more old people will be able to maintain good vision as they age. Since many serious eye conditions are treatable when detected at an early age, it is important to have periodic eye examinations, especially as one approach the sixth decade of life.
Specialized tests :
- Fundus Flurescein Angiogram: A special dye is injected in to the veins of the arm and when the dye is passing into the circulation of the eye, pictures are taken with the special camera.By examining the images captured by the cameras, the eye surgeon can determined the size and the location of the abnormal blood vessels in the retina.
- Ocular Coherence Tomography: To detect the swelling and bleeding blood vessels below retina.
Wet ARMD, is caused by leaking blood vessels, it needs to be sealed. It can be done by:
- laser
- Intra vitreal injections of Avastin or lucentis.
1. Laser: Earlier the recommendation was ARGON laser treatment or PDT
(Photo dynamic therapy) which did not give desired results.
2. The recent treatment is with special injections like Avastin / Lucentis.
These injections are antii-VEGF drugs that block the trouble-causing VEGF, reducing the growth of abnormal blood vessels and slowing their leakage.
The recent development of anti-VEGF medications have become a
path breaking advance in the treatment of wet AMD.Bevacizumab (Avastin) and Ranibizumab (Lucentis) are two very useful drugs. Most patients will retain the vision they have and some will regain some of the lost vision after these treatments.
Injection Lucentis/ Injection Avastin is injected as once every 6 to 8 weeks till the patients improve. Then the patients are evaluated after 3 months.The above doses generally take care of the acute need of treatment and no further injections are required, unless the condition changes over time.
The follow ups are simple and can be done by a local eye surgeon if not residing in our city. These procedures will help in restoring the sight.
Tips for AMD patients :
- Making a few simple lifestyle changes will have positive effect on the quality of vision.
- To make reading easier : Use bright focus light, e.g. focus light.
- Shine the light on your reading material. Wear your reading glasses.
- Incorporate dark leafy vegetables in your diet.
- Stop smoking.
- Monitor your vision daily with an AMSLER’S GRID. This is used to screen for macular degeneration.
How to perform Amsler’s Test:
- Wear your reading glasses.
- Hold the chart approximately 14-16 inches in bright light .
- Cover one eye.
- Look at center dot.
- Note irregularities (wavy, size, gray. fuzzy).
- Repeat the test with your other eye.
- Contact ophthalmologist if you see any irregularities or notice any changes.
Normal Amsler Grid
Grid seen by patients with ARMD
Have any queries please feel free to leave a comment subsequent response is assured.
For videos please click the image:
For more details please click on the link:
http://www.rushabheyehospital.com/
Download.pdf
1 comments:
Thanx for the info...I was avidly lookin forward for it....
Thanks again
Post a Comment