Medical retina
What is Diabetic Retinopathy?
Diabetic retinopathy typically presents no symptoms during the early stages.
The condition is often at an advanced stage when symptoms become noticeable. On occasion, the only detectable symptom is a sudden and complete loss of vision.
The risk of developing diabetic retinopathy is known to increase with age as well with less well-controlled blood sugar and blood pressure level.
Signs and symptoms of diabetic retinopathy may include:
What is Diabetic Retinopathy?
Diabetic retinopathy is the most common form of diabetic eye disease. Diabetic retinopathy usually only affects people who have had diabetes (diagnosed or undiagnosed) for a significant number of years.
Retinopathy can affect all diabetics and becomes particularly dangerous, increasing the risk of blindness, if it is left untreated.
The risk of developing diabetic retinopathy is known to increase with age as well with less well-controlled blood sugar and blood pressure level.
All people with diabetes should have a dilated eye examination at least once every year to check for diabetic retinopathy.
Diabetic retinopathy occurs when changes in blood glucose levels cause changes in retinal blood vessels. In some cases, these vessels will swell up (macular oedema) and leak fluid into the rear of the eye.
In other cases, abnormal blood vessels will grow on the surface of the retina. Unless treated, diabetic retinopathy can gradually become more serious and progress from ‘background retinopathy’ to seriously affecting vision and can lead to blindness.
Diabetic retinopathy includes three different types :
What are the Causes and Risk Factors of Diabetic Retinopathy?
Anybody with diabetes is at risk of developing diabetic retinopathy. However, there is a greater risk if the person:
Damage to the network of blood vessels that nourish the retina is the key cause of diabetic retinopathy.
High glucose levels damage these vessels and restrict the flow of blood to the retina. The problems with the blood vessels can be as mild as tiny bulges in the vessel wall that occasionally leak blood without affecting vision.
However, in the advanced stages of the condition, these blood vessels may become completely blocked. The eye then produces new, less stable blood vessels. The new vessels break easily and leak into the vitreous gel of the eye. The bleeding causes blurred and patchy vision by further blocking the retina.
This bleeding, on occasion, forms scars that can separate the retina and the eye, leading to a detached retina. As symptoms develop, a person with DR becomes increasingly likely to experience complete vision loss.
How can Diabetic Retinopathy be treated?
Laser surgery is often used in the treatment of diabetic eye disease, but each stage of diabetic retinopathy can be treated in a different way.
Background retinopathy has no treatment but patients will need regular eye examinations.Maculopathy is usually treated with laser treatment (tiny burns that help to prevent new blood vessel growth and improve the nutrient and oxygen supply to the retina).
This is usually painless and has no side effects, but can influence night driving and peripheral vision.
This type of laser treatment for diabetic retinopathy will not improve vision, but it can prevent deterioration. Proliferative retinopathy is also treated with lasers, with a scattering over the whole retina. This destroys the starved area of the retina.
Serious diabetes retinopathy cases may require eye surgery.
This is usually diagnosed due to bleeding in the eye, late-stage proliferative retinopathy or ineffective laser treatment. This type of diabetic retinopathy eye surgery is called a vitrectomy.
BACKGROUND RETINOPATHY
Background retinopathy, also known as simple retinopathy, involves tiny swellings in the walls of the blood vessels. Known as blebs, they show up as small dots on the retina and are usually accompanied by yellow patches of exudates (blood proteins).
Background diabetic retinopathy requires regular monitoring by an ophthalmologist. It is therefore important to attend regular retinopathy screening appointments.
DIABETIC MACULOPATHY
The macula is the most well-used area of the retina and provides us with our central vision. Maculopathy refers to a progression of background retinopathy into the macular.
The macula is the most well-used area of the retina and provides us with our central vision. Maculopathy refers to a progression of background retinopathy into the macular.
This can cause vision problems such as difficulty with reading and or seeing faces in the centre of your vision.
PROLIFERATIVE RETINOPATHY
This can cause vision problems such as difficulty with reading and or seeing faces in the centre of your vision.
These can then bleed into the eyes, cause the retina to detach, and seriously damage vision. If left untreated, this can cause blindness. If proliferative retinopathy is regularly monitored and treated, the development of retinopathy can help be limited and more severe damage may be prevented.
How is Diabetic Retinopathy diagnosed?
Diabetic retinopathy generally starts without any noticeable change in vision. However, an ophthalmologist, or eye specialist, can detect the signs.
It is crucial for people with diabetes to have an eye examination at least once or twice annually, or when recommended by a physician.
The following methods are commonly used to diagnose diabetic retinopathy:
Dilated eye exam
Photographs are taken of the interior of the eye. During the eye examination, the doctor can detect the presence of:
These drops may sting, and the bright lights of the photographs can startle the person receiving the test. In high-risk individuals, the eye drops may cause an increase in ocular pressure.
Fluorescein angiography
Drops are used to dilate the pupils, and a special dye called fluorescein is injected into a vein in the patient’s arm. Pictures are taken as the dye circulates through the eyes. The dye may leak into the retina or stain the blood vessels if the blood vessels are abnormal.
This test can determine which blood vessels are blocked, leaking fluid, or broken down. Any laser treatments can then be accurately guided. For around 24 hours after the test, the skin may turn yellowish, and urine dark orange, as the dye exits the body.
Optical coherence tomography (OCT)
This noninvasive imaging scan provides high-resolution cross-sectional images of the retina, revealing its thickness. After any treatments, scans may be used later to check how effective treatment has been.
OCT is similar to ultrasound testing but uses light rather than sound to produce images. The scan can also detect diseases of the optic nerve.
Prevention of Diabetic Retinopathy?
For the majority of people with diabetes, Diabetic Retinopathy is an inevitable consequence.
However, patients with diabetes who successfully manage their blood sugar levels will help to prevent the onset of a severe form of Diabetic Retinopathy.
High blood pressure, or hypertension, is another contributing factor. Patients with diabetes need to control their blood pressure by:
Treatment Options of Diabetic Retinopathy?
Treating Diabetic Retinopathy depends on several factors, including the severity and type of Diabetic Retinopathy, and how the person with Diabetic Retinopathy has responded to previous treatments.
With NPDR, a doctor may decide to monitor the person’s eyes closed without intervening. This is known as watchful waiting.
Individuals will need to work with their doctor to control diabetes. Good blood sugar control can significantly slow the development of DR.
In most cases of PDR, the patient will require immediate surgical treatment. The following options are available:
Focal laser treatment, or photocoagulation
The procedure is carried out in a doctor’s office or an eye clinic. Targeted laser burns seal the leaks from abnormal blood vessels. Photocoagulation can either stop or slow down the leakage of blood and buildup of fluid in the eye.
People will usually experience blurry vision for 24 hours following focal laser treatment. Small spots may appear in the visual field for a few weeks after the procedure.
Scatter laser treatment, or pan-retinal photocoagulation
Scattered laser burns are applied to the areas of the retina away from the macula, normally over the course of two or three sessions. The macula is the area at the center of the retina in which vision is strongest.
The laser burns cause abnormal new blood vessels to shrink and scar. Most patients require two or three sessions for the best results.
Individuals may have blurry vision for 24 hours following the procedure, and there may be some loss of night vision or peripheral vision.
Vitrectomy
This involves the removal of some of the vitreous from within the eyeball. The surgeon replaces the clouded gel with a clear liquid or gas. The body will eventually absorb the gas or liquid. This will create new vitreous to replace the clouded gel that has been removed.
Any blood in the vitreous and scar tissue that may be pulling on the retina is removed. This procedure is performed in a hospital under general or local anaesthetic.
The retina may also be strengthened and held in position with tiny clamps.
After surgery, the patient may have to wear an eye patch to gradually regain use of their eye, which can tire after a vitrectomy.
If gas was used to replace the removed gel, the patient should not travel by plane until all gas has been absorbed into the body. The surgeon will tell the patient how long this should take. Most patients will have blurry vision for a few weeks after surgery. It can take several months for normal vision to return.
Surgery is not a cure for diabetic retinopathy. However, it may stop or slow the progression of symptoms. Diabetes is a long-term condition, and subsequent retinal damage and vision loss may still occur despite treatment.
NEXT STEP
Before you agree to the test or the procedure make sure you know:
Diabetic eye care
Regular eye exams are a must for diabetic patients. Early detection and treatment of diabetic-related eye changes are vital to prevent vision-threatening complications and blindness.
Diabetic patients can experience various changes in the eyes, such as changes in refractive error, cataracts, iridopathy, retinopathy, macular edema, and optic neuropathy. Diabetic retinopathy is the major concern that can be prevented, but if left untreated, it can lead to blindness.
Eye Care for Diabetics
The most important point is that even in advanced cases, the disease may progress a long way without symptoms; hence, regular dilated eye examinations for people with diabetes are very important.
Diabetic eye care includes complete eye examination to look for the changes in eye due to diabetes. This includes visual acuity, refraction, lensometer, dilated fundus examination and investigation to detect diabetic retinopathy.
Detection and Diagnosis
Diabetic retinopathy has been graded according to the severity of the disease. In our hospital, we have retina specialists who are well-versed in treating diabetic retinopathy and give proper care and treatment.
Diabetic patients are also more at risk for developing glaucoma, a disease of the eye. Glaucoma is a disease that affects the optic nerve due to increased eye pressure.Regular monitoring of eye pressure is essential for diabetic patients. Diabetic retinopathy patients may not have any symptoms until it reaches an advanced stage. There may be frequent changes in glass power or a decrease in vision due to cataracts. Diabetic retinopathy is diagnosed on a dilated fundus evaluation. In our hospital, all diabetic patients are evaluated by the retina specialist to detect any subtle changes in the eyes.
Treatment options for diabetics
Diet, exercise, and special medication are the best ways to control diabetes. With the latest advancement in the field of medicine, vision loss due to diabetic retinopathy could be treated with laser photocoagulation.All diabetic patients undergo a dilated examination and further investigation if needed. Various tests that can help in the diagnosis and treatment of diabetic eye changes are available in our hospital.
Fundus photography is done to have a document and can be used for monitoring diabetic changes. Our hospital offers state-of-the-art optical coherence tomography (OCT) tests, ensuring high-quality diagnostic imaging for our patients.
This test can determine the amount of fluid collection in the retina, the extent of bleeding, or any other complications in the eye. This test gives a microscopic cross-section of the retinal layers of the eye. These tests are done in our hospital and used effectively for the treatment of patients. Other tests, like fundus fluorescein angiography, are also done in our hospital. This test can detect the exact location of bleeding and leakage in the retina so that an appropriate laser can be given to prevent further complications.
What is Retinal Laser Photocoagulation?
Ophthalmologists employ retinal laser photocoagulation to treat a variety of retina-related illnesses. The conditions include diabetic retinopathy, retinal vein blockage, retinal breaks, central serous chorioretinopathy, and choroidal neovascularization. Unlike what many patients believe, the process is not similar to surgery. During this therapy, the doctor ensures that the laser beam (focused light waves) falls on the correct location in the retina. During this process, heat energy is created, and retinal coagulation occurs, resulting in the intended treatment.
Retinal lasers
Retinal laser photocoagulation is an in-office procedure used to treat a number of retinal conditions, including retinal tears, diabetic retinopathy, macular edema and retinal vein occlusion. It is most frequently used to seal a retinal tear to prevent development of a retinal detachment, a potentially blinding condition. Retinal laser photocoagulation is also used to seal or destroy leaking blood vessels to prevent further retinal damage and preserve sight.
The laser procedure works by creating small areas of scar tissue that can seal off a tear or leaking blood vessels. It can also slow the growth of abnormal blood vessels (neovascularization) in the eye. The procedure cannot typically restore vision that is already lost, but it can reduce your risk of experiencing future vision loss.
Anti VEGF
Anti–vascular endothelial growth factor therapy, also known as anti-VEGF (/vɛdʒˈɛf/) therapy or medication, is the use of medications that block vascular endothelial growth factor. This is done in the treatment of certain cancers and in age-related macular degeneration. They can involve monoclonal antibodies such as bevacizumab, antibody derivatives such as ranibizumab (Lucentis), or orally-available small molecules that inhibit the tyrosine kinases stimulated by VEGF: sunitinib, sorafenib, axitinib, and pazopanib (some of these therapies target VEGF receptors rather than the VEGFs).
Types and benefits of Retina Laser
According to the type of retinal disorder, laser therapy is provided in different ways.
Proliferative Diabetic Retinopathy (PDR)
Proliferative diabetic retinopathy is a form of advanced or end-stage diabetic retinopathy. Due to the long duration of diabetes and uncontrolled blood sugar levels, the retinal blood vessels undergo changes which happen in stages, ultimately leading to PDR. PDR is a vision-threatening disorder. When timely treatment is not provided, it can cause complications like bleeding within the eyes from the abnormal vessels and/or can retinal detachment.
Retinal laser therapy is helpful in PDR as it decreases the risk of such complications. The doctor performs pan-retinal photocoagulation (PRP) to treat PDR.
The retina is a 360-degree structure that is responsible for vision. The central retina is called as macula and is the chief zone responsible for fine vision. During proliferative diabetic retinopathy, the doctor applies laser therapy to the poorly vascular retinal areas sparing the macula. Proliferative diabetic retinopathy therapy is provided in three to four sessions since the almost 360-degree retina is slowly covered with laser spots. The formation of abnormal blood vessels and undue complications are prevented by this procedure.
Diabetic Macular Edema (DME)
DME is abnormal fluid collection leading to swelling at the level of the macula, causing vision loss. Retinal laser photocoagulation is beneficial in some cases of DME. Here, minimal laser spots are given targeting the leaky macular blood vessels to reduce the swelling.
Retinal Vein Occlusion (RVO)
In RVO, the entire retinal vessel or a part of the retinal vessel gets blocked due to various reasons leading to abnormal blood flow to the part of the retina supplied by the vessel. Here, Retinal laser therapy is useful, similar to PRP in PDR, as explained before.
Retinal Tears, Holes and Lattice Degeneration
Retinal tears, holes, and lattice degenerations (areas of retinal thinning) affect around 10% of the general population and are more prevalent in myopes. If not treated, there is always a risk of retinal detachment from the breaks. In such circumstances, the doctor can delimit the retinal fractures with two to three rows of laser spots, resulting in dense adhesion in the surrounding retina and lowering the chance of retinal detachment. It is necessary to screen and laser such lesions prior to LASIK and cataract surgery.
Central Serous Chorioretinopathy (CSC) and Choroidal Neovascularization
Both disorders cause macular leaks, resulting in fluid collection and visual loss. Retinal laser therapy targeting the leaking areas may be effective in some circumstances, depending on the specialist's opinion.
Patient preparation
The laser operation is only conducted after topical anesthesia has been administered. To reduce pain, eye drops would be administered before the treatment. The treatment is relatively painless. During therapy, the patient may experience slight pricking sensations. Depending on the patient's illness, the complete operation could last anywhere from five to twenty minutes.
After the procedure
The patient might feel mild glare and visual discomfort for a day or two. He or She will be advised to use antibiotic and lubricant eye drops for 3 to 5 days, depending on the type and duration of the procedure. Extensive PRP in diabetic retinopathy can lead to a decrease in contrast sensitivity and colour vision.
Types and method
There are two methods by which laser therapy can be performed: Contact and Non-Contact methods. In the contact procedure, a lens with a lubricating gel will be placed over the patient’s eyes, and laser therapy would be delivered in sitting position.
In the non-contact method, the patient is made to lie down, and laser therapy is delivered. Sometimes the doctor might apply minimal pressure around the patient’s eyes with a handheld instrument.
