Signs and symptoms

• Microaneurysms: In most cases, these are the earliest clinical abnormality detected. They appear as minute, discrete, circular, dark red spots near to but apparently separate from the retinal vessels [9].
• Hemorrhages: They characteristically occur in the deeper layers of the retina, are round and regular in shape, and are called 'blot' hemorrhages. In hypertensive patients, superficial flame-shaped hemorrhages may also occur.
• Hard exudates: These are characteristic of diabetic retinopathy [9]. They result from leakage of plasma from abnormal retinal capillaries and can vary in size from tiny specks to large patches.
• Cotton-wool spots: Most often seen in rapidly progressive retinopathy and hypertension, these spots represent arteriolar occlusions.
• Venous beading: Sausage-like dilatation and increased looping of veins indicate widespread capillary nonperfusion.

Presenting complaints

A patient may initially complain of blurred or fluctuating vision and difficulty in color perception. This may be more evident in one eye than in the other. The patient may then complain of empty or dark areas and floating spots or lines in his vision. In severe form of this condition, the patient may eventually suffer from complete loss of vision.

• Splinter Hemorrhage

  Appear similar to microaneurysms if they are small; they occur as microaneurysms rupture in the deeper layers of the retina, such as the inner nuclear and outer plexiform layers Flame-shaped hemorrhages: Splinter hemorrhages that occur in the more superficial [emedicine.com]

• Blurred Vision

  Both the microaneurysms and the new blood vessels may rupture causing the leakage of blood into the retina and blurred vision. [news-medical.net]

  Blurred vision happens for two reasons: with diabetic macular edema, leaky blood vessels cause swelling of the macula, which can lead to blurred vision. with proliferative diabetic retinopathy, fragile new blood vessels on the retina cause bleeding in [diabetes.ie]

  If you diabetic and experience blurred vision, you should visit an eye specialist immediately. [moorfields.nhs.uk]

  This changes the curvature of the lens, leading to blurred vision. However, once blood sugar levels are controlled, blurred distance vision will improve. [aoa.org]

  Symptoms Diabetic neuropathy may cause: Spots floating in the visual field Vision loss Poor night vision Blurred vision Image modified from National Eye Institute, National Institutes of Health Risk Factors Diabetes Kidney Disease: people with kidney [faculty.washington.edu]

• Background Retinopathy

  This type of diabetic retinopathy eye surgery is called vitrectomy. Read more on treating retinopathy Background retinopathy Background retinopathy, also known as simple retinopathy, involves tiny swellings in the walls of the blood vessels. [diabetes.co.uk]

  One patient had mild background retinopathy on both eyes, with visual acuity of 1.0 and 0.7 after cataract extraction plus intravitreal triamcinolone injection. [ncbi.nlm.nih.gov]

  Diabetic Retinopathy What causes Diabetic Retinopathy? Diabetic retinopathy first manifests itself slowly over the years as background retinopathy, which is the early stage of diabetic retinopathy. [snec.com.sg]

• Cotton Wool Spots

  Cotton-wool spots are areas of microinfarction of the retinal nerve fiber layer that lead to retinal opacification; they are fuzzy-edged and white and obscure underlying vessels. [merckmanuals.com]

  Screening for retinopathy is undertaken using conventional color fundus photography and relies on the identification of hemorrhages, vascular abnormalities, exudates, and cotton-wool spots. These can sometimes be difficult to identify. [ncbi.nlm.nih.gov]

  Diabetic retinopathy - Three main categories exist: background, or "simple," retinopathy, consisting of microaneurysms, hemorrhages, exudates, and retinal edema; preproliferative retinopathy with arteriolar ischemia manifested as cotton-wool spots (small [health.am]

• Retinal Hemorrhage

  We present the case of an early stage diabetic retinopathy patient presented with retinal hemorrhages in the superior temporal area and disc hemorrhages of disc nasal area. The patient was diagnosed with mild NPDR on fundus examinations. [ncbi.nlm.nih.gov]

  Any NVD with vitreous hemorrhage 3. NVE ≥ ½ disc area with vitreous hemorrhage High-risk PDR was also defined as three or more of the following high-risk characteristics (HRC’s): 1. Presence of vitreous hemorrhage or pre-retinal hemorrhage 2. [bu.edu]

  These symptoms are typically caused by vitreous hemorrhage or traction retinal detachment. [merckmanuals.com]

• Macula Edema

  The swelling in the macula (edema), can be caused by a few leaking vessels or many scattered throughout the macula. This may cause slight to very severe blurring of vision. [arleoeye.com]

  Fluid can leak into the part of the eye where focusing occurs, the macula. When the macula swells with fluid, a condition called macula edema, vision blurs and can be lost entirely. [thevisioncarecenter.com]

  Macula edema is noted when areas of your retina are shown to contain spaces filled with fluid. Treatment and Drugs In mild cases, treatment for diabetic retinopathy is not necessary. [umkelloggeye.org]

  During the stages of mild and moderate non-proliferative diabetic retinopathy, no treatment is needed unless macula edema is present. [rgw.com]

• Social Isolation

  Significant visual deficit from diabetic retinopathy can lead to social isolation of older individuals by limiting driving, the ability to leave the home or remain in the home safely, and the ability to watch television or read. [ncbi.nlm.nih.gov]

Workup includes a complete history and physical examination. The following tests should be conducted:

Laboratory tests

• Complete blood count
• Resting blood sugar
• Fasting blood sugar
• HbA1c levels
• Liver function tests

Imaging

• Fluorescein angiography: This is a test in which pupils are dilated and photographs of the vessels are taken. Then a radiocontrast dye is injected and photographs are taken again once the dye has perfused to all eye vessels.
• Optical Coherence Tomography (OCT): OCT provides us with cross-sectional images of the retina which help in both identifying retinal thickening if any, as well as monitoring the progress of treatment.
• B-scan Ultrasonography may also be done.

Medications

Multiple doses of intravitreal injections of anti-VEGF drugs such as bevacizumab show good results [10]. Similar drugs like Ranibizumab and a corticosteroid Triamcinolone may also be given.

Photocoagulation

In cases of nonproliferative DR, laser photocoagulation may be used to treat macular edema due to vascular leakage.
In patients with proliferative diabetic retinopathy, pan-retinal photocoagulation is used to spare the macular area and treat the entire diseased retina.

Vitrectomy

This procedure may be used in some patients with proliferative diabetic retinopathy.

Cryotherapy

This procedure may be used when the patient already suffers from other eye diseases like cataracts, etc.

Blood sugar level control

This is the primary mode of controlling the progression of retinopathy. By bringing blood glucose to normal levels, edema and other such conditions involved in diabetic retinopathy can be lessened.

The longer a person has diabetes, the higher his chances of developing diabetic retinopathy [8]. If a person has been diagnosed early, he would have well-defined leakage and good perifoveal perfusion. His vision loss would be mild and exudates would be minimal. In such cases, the prognosis is favorable as with the right control and treatment, the progression of the disease may be halted.

If on the other hand, a patient with diabetic retinopathy also has hypertension and/or kidney disease, and has already suffered from irreversible macular ischemia and edema, the prognosis is bad.

Complications

Complications include all the factors that may worsen the ischemic state of the eye such as:

• Hypertension
• Smoking
• Hyperlipidemia
• Renal diseases
• Cataract formation
• Glaucoma

As the name indicates, the primary cause of diabetic retinopathy is diabetes. In type I diabetes mellitus, the chances of developing this condition are comparatively less. In patients with type II diabetes mellitus, however, the incidence of this condition is directly proportional to disease duration.

Other causes include hypertension and hyperlipidemia which may exacerbate preexisting diabetes and increase the risk of developing diabetic retinopathy. Studies reveal that pregnant women that have this condition have a 4-5% chance of progression to a more severe stage.

Diabetes is responsible for approximately 8000 eyes becoming blinded each year, meaning diabetes is responsible for 12% of blindness [2].

A recent estimate of the prevalence of diabetic retinopathy in the US showed a high prevalence of 28.5% among those with diabetes aged 40 years or older [3]. Clearly the longer a person has diabetes, i.e the older a person is, the more likely he is of developing retinopathy.

The retinal vasculopathy of diabetes mellitus can be classified into the background (pre-profilerative) diabetic retinopathy and proliferative diabetic retinopathy [4].

Pre-proliferative diabetic retinopathy

Hyperglycaemia induced intramural pericyte death and thickening of the basement membrane leads to vascular wall incompetence. These damages change the formation of the blood-retinal barrier and also make the retinal blood vessels more permeable [5]. Smaller vessels may occlude and the weakened walls of the larger vessels may dilate. As a result, microaneurysms and macular edema occur.

Proliferative diabetic retinopathy

Retinal ischemia can result in the up-regulation of pro-angiogenesis factors such as VEGF and lead to retinal angiogenesis [6]. Retinal neovascularization may be accompanied by the development of a neovascular membrane on the iris surface, presumable secondary to increased levels of VEGF in the aqueous humor [7]. Gradually, scar tissue develops which may cause retinal detachment and/or build up of intraorbital pressure leading to glaucoma and optic nerve damage.

[…] conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy. [doi.org]

That’s why it’s vital that you know why you’re at risk of eye problems and what you can do to prevent them. [diabetes.org.uk]

Prevention and early diagnosis improve the visual prognosis of the illness. This is not merely a truism. Nowadays most patients can avoid reaching extreme situations of high risk. However, it is vital to have regular preventative examinations. [institutmacula.com]

Diabetes mellitus is a metabolic disorder that results in excess glucose in the blood. This excess amount of glucose causes widespread complications.

The most common and potentially most blinding of these complications, however, is diabetic retinopathy (DR) [1]. In this condition, a person's retinal vessels suffer ischemia and damage due to high blood glucose levels resulting in visual loss and in the worst case - blindness.

Diabetic retinopathy is a complication of long-standing, and often uncontrolled, diabetes mellitus. It is caused due to raised glucose levels in the blood which damage the blood vessels of the eyes, leading to first blurred vision and finally blindness. If you are diabetic and feel that your visual power has decreased, you should schedule a consultation with an eye specialist immediately.