Diabetic Retinopathy, as the word implies, is a medical condition which causes progressive damage to the retina; mainly to the patients who have diabetes. When left untreated, the severity of Diabetic Retinopathy can eventually lead to blindness.
Diabetic patients have sugar (glucose) imbalance in their body as the metabolic disease interferes with insulin production. Later stages of diabetes cause damage to major organs of the body and eye is one of the first organs to get affected.
Analysts predict that the number of Americans affected by Diabetic Retinopathy is going to double up over the course of time. Hispanic Americans getting affected by this case are expected to reach up to 5.3 million by 2050.
Symptoms
Much like Macular Edema, self-diagnosis of Diabetic Retinopathy is very rare as you never know the onset of this eye complication. In most cases, patients are left clueless until severity and significant damages start to occur. Some of the common symptoms of Diabetic Retinopathy include:
- Loss of central vision – You can diagnose Diabetic Retinopathy if you start losing sight or suffer poor vision while doing activities like reading and driving.
- Colour Blindness – It is very common for a person to suffer from colour blindness when Diabetic Retinopathy prevails.
- Night Blindness – If you start developing the inability to see during night-time, you might as well consider it to be the first effects of Diabetic Retinopathy.
- Black Spots & Holes – One of the most dreadful initial effects of Diabetic Retinopathy is developing black structures that interfere with vision. To see it from the sufferer’s perspective, it would look something like –
Stages
Diabetic Retinopathy is classified into 2 stages; NPDR (Non-proliferative Diabetic Retinopathy) and PDR (Proliferative Diabetic Retinopathy).
- Stage 1 (NPDR)
During the early stages of Diabetic Retinopathy, the effects are indeed mild. In the 1st stage, blood vessels in the retina start to weaken and bulge out from their walls. This effect is also known as microaneurysm. These weakened blood vessels then release fluid into the retina which causes the macula to swell. NPDR is barely noticeable and doctors use fundus photography to confirm the onset of stage 1.
With time, the discharged fluid can fill up the macular region which leads to distorted vision which is not the same in both eyes. During NPDR, 10% of patients stand a high chance of developing vision loss.
- Stage 2 (PDR)
When Diabetic Retinopathy enters stage 2, the disease gets more advanced. The early-on changes in PDR include growing of fragile blood vessels in the retina and vitreous. This phenomenon is also called neovascularization.
Then there are micro-disruptions in these fragile blood vessels which cause them to leak blood at the back of the eye which eventually interferes with vision. The retina eventually detaches due to the formation of scar tissue and development of glaucoma. This episode is followed by an extreme pain in the eye which eventually leads to blindness.
Causes
Although Diabetic Retinopathy usually occurs in patients who are already suffering from diabetes, other factors also contribute to the risk of developing this disease. Such factors include:
- Pregnancy – As pregnant women are prone to develop gestational diabetics, therefore there’s a high chance that diabetes might cause Diabetic Retinopathy.
- Race – Although researchers haven’t come up with specific reasons as to why certain groups of races get affected by Diabetic Retinopathy the most, White, African and Hispanic Americans hold the highest rate of the severity of this medical condition.
- Other Medical Conditions –Apart from diabetes, other medical conditions such as high cholesterol and high blood pressure also trigger the risk of Diabetic Retinopathy.
Diagnosis
Doctors usually diagnose Diabetic Retinopathy through a comprehensive eye examination. To diagnose the retina and macula, doctors go through a rigorous set of evaluations including:
-Patient History
Before starting with all the diagnosis, doctors generally go through the patient’s medical history to determine the cause of vision difficulties. In this step, the doctor determines whether it’s actually diabetes or other medical condition that is hampering eye health.
-Measurement of Visual acuity
Doctors also perform measurement of visual acuity to determine the loss of central vision. In case of minor central vision loss, the doctor might even prescribe eyeglasses for refraction of the eye lenses.
-Retinal Photography
To get a clearer picture of the status of retina, doctors conduct retinal photography for severely affected patients.
-Evaluating Ocular Structures
Further diagnosis of Diabetic Retinopathy involves the doctor evaluating the retina by dilating the pupil. The doctor might even conduct measurements for eye pressure to determine the severity of Diabetic Retinopathy.
Research
Fundoscopic imaging and analyses
Fundoscopic imaging is one of the most favoured tools (diagnostics) by doctors to sort out Diabetic Retinopathy. Doctors take images of the retina to figure out abnormalities that are triggered by Diabetic Retinopathy. Doctors also use colour fundus photography to stage Diabetic Retinopathy.
To develop the further treatment plan, doctors access Fluorescein Angiography to take note of the abnormal growth of blood vessels. Now, computer-aided diagnosis has taken a massive leap of progress which involves the analysis of fundoscopic images to be automated. This computer automated diagnosis has several benefits including accuracy and time efficiency.
Blood Pressure Control
Controlling blood pressure is one rare measure that doctors take to cater prevention of Diabetic Retinopathy. According to a Cochrane study http://www.cochrane.org/CD006127/EYES_blood-pressure-control-for-diabetic-retinopathy, controlling or reducing blood pressure has helped prevent Diabetic Retinopathy up to 5 years for patients who already have diabetes.
However, there is no evidence of blood pressure control slowing down the progression of Diabetic Retinopathy or preservation of the clarity of the vision.
Stem Cell Therapy
Stem cell therapy for Diabetic Retinopathy is under clinical trials as of now. According to the analogy of clinical trials, doctors can use the patient’s bone marrow to derive stem cells and inject them into the degenerated areas for regenerating the vascular system.
For further information, read https://www.ncbi.nlm.nih.gov/pubmed/26454200.
C-Peptide
As C-peptide (aka Connecting Peptide) has shown promising results in treating vascular degeneration, Cebix (read http://www.xconomy.com/san-diego/2015/02/23/cebix-shuts-down-following-mid-stage-trial-of-c-peptide-drug/#) organised a program of $50 million to complete the Phase llb trail in 2014. The trial showed no difference between placebo and C-peptide which caused the company to shut down the program entirely.
Light Treatment
In 2016, Noctura (http://noctura.com/) developed a medical device which the patients can use as a sleeping mask to treat Diabetic Retinopathy. As per the clinical trials, the mask emits green light on the eyelids which supposedly stops the retina’s rod cells to adapt dark light. This, in turn, reduces oxygen requirement which has a counter effect on the formation of blood vessels.
Treatment
As of now, there are 3 major treatments for Diabetic Retinopathy which aid in restoring vision. Having said that, there’s no single solution for the complete cure of Diabetic Retinopathy till date.
Monitoring the symptoms vigilantly and getting optimal glycemic control is the best way to prevent the onset and delay further development of Diabetic Retinopathy. Here are the 3 main treatments:
1. Laser Photocoagulation
For treating Diabetic Retinopathy, doctors adapt Laser Photocoagulation into two usages. First, Laser Photocoagulation can be used to control neovascularization via panretinal coagulation and secondly for treating macular edema.
- Panretinal Photocoagulation
Panretinal Photocoagulation aka scatter laser treatment is designed for treating PDR (Proliferative Diabetic Retinopathy). The process involves reducing the oxygen demand in the retina by creating 1,600 to 2,000 burns.
Before the ophthalmologist begins with the procedure, the physician numbs the eye by anaesthetic drops and dilates the pupil. The doctor may choose between pattern scan laser or a single spot laser.
From the patient’s perspective, you will see flashes of light during the procedure. This is accompanied by a stinging-like sensation. After the laser surgery, vision remains blurry for the rest of the day and the patients might suffer from a mild headache later on. Given the effectiveness of Panretinal Photocoagulation, this laser surgery involves several side effects too including reduced night and colour vision.
- Laser Photocoagulation for macular edema
To treat macular edema with Laser Photocoagulation, doctors create a modified grid; a C-shaped pattern at the posterior pole with low-intensity burns. Clearing macular edemas helps in reducing the risk of vision. Read https://www.ncbi.nlm.nih.gov/pubmed/2866759.
2. Vitrectomy
Apart from laser surgery, Vitrectomy surgery is another treatment that doctors prefer; especially in the case where the vitreous contains lots of blood. To restore vision with vitrectomy, surgeons remove the blurry vitreous and replace it with a saline solution.
Vitrectomy doesn’t require special numbness and can be done under local anaesthesia. The surgery involved the doctoring making a tiny incision in the white portion of the eye to remove the vitreous. The doctor uses the same incision as a gateway to insert the saline solution.
The after-effects of the surgery include redness in the eye and sensitivity. In usual cases, patients are required to wear an eye patch for a couple of days. The doctor also prescribes medicated eye drop for prevention of infection.
3. Medication
Intravitreal anti-VEGF
Multiple doses of anti-VEGF intravitreal injection combined with Modified Grid Laser Photocoagulation works well for treating diabetic macular edema.
Intravitreal triamcinolone acetonide
Steroid preparation including Triamcinolone has lasting benefits in treating macular edema. The steroid is injected in the vitreous cavity which reduces the swelling of the retina that results in increased visual acuity.
In most patients, the effects of this steroid last for a time period of 3 months. This, in turn, necessitates repetition of the dosage to maintain the consistency of benefits.
Prevention
Management and prevention of the onset of Diabetic Retinopathy (especially Proliferative Diabetic Retinopathy) entirely depends upon the management of diabetes. However, the patients can take several measures to prevent PDR. Some of these measures include:
- Cholesterol and Blood Pressure Control
Diabetics with abnormal lipid metabolism and high blood pressure are vulnerable to get affected by Diabetic Retinopathy. As these factors can trigger the development of vascular changes at an alarming rate, Doctors recommend diabetics to maintain a normal BP and manage serum lipid levels by undergoing regulated medications.
- Blood Sugar Control
It is always best to maintain a healthy lifestyle by doing physical activity on a regular basis and maintaining a healthy diet. Diabetics are often advised to consult a diabetic specialist for undergoing the best-suited hypoglycemic medications.
- Quitting Tobacco
Smoking leads to abnormal blood sugar levels which create the risk of developing atherosclerosis. Similarly, hazardous habits like alcohol consumption and illicit drug abuse are a strict no for diabetics to prevent Diabetic Retinopathy.
- Eye Examination
It is often recommended that a diabetic should visit a specialist for ensuring the working of hypoglycemic medication. Visiting an eye specialist every once in a while in 3 months is helpful to come up with diagnostics of vascular changes.
Alternatives to medication
As discussed earlier, there’s no definite cure to Diabetes or Diabetic Retinopathy. However, there are several herbal supplements which have seemed to work well for patients in the past. Some of these supplements that help in delaying the onset of Diabetic Retinopathy include:
- Butcher’s broom
- Pycnogenol (Pine bark)
- Bilberry
- Grape Seed Extract
- Gingko Biloba
Communities
As the percentage of diabetics suffering from Diabetic Retinopathy is increasing, several communities encourage patients to share up for creating a positive perception. Also, such communities provide information and make the patients aware of the available treatment options. Some of these communities include:
Macular Society: https://healthunlocked.com/macularsociety?utm_campaign=diabetic-retinopathy&utm_medium=syndicated&utm_source=nhs.uk&utm_term=web_part_id_20
Diabetes Research & Wellness Foundation:
https://healthunlocked.com/drwfdiabetes/about