Retina and diabetes
What exactly is the retina?
The eye is like a camera (camera). The lens in front of the eye focuses the light on the retina. You can think of the retina as the camera film. In fact it is a photosensitive layer of tissue inside the eye, it receives the light and sends the image (visual information) in the human brain
Diabetes and vision
Diabetes is a disease that occurs in all age groups with key characteristic high levels of glucose (sugar) in the body. But diabetes is also capable of affecting vision, causing a number of diseases and symptoms. The longer that someone is suffering from diabetes, the greater the risk of developing problems in vision.
What is diabetic retinopathy?
The most serious among the diabetic eye diseases concerns the retina and it is called diabetic retinopathy (diabetic retinopathy). The disease causes severe damage to the blood vessels that supply nutrients to the retina. This damage caused to those result in hemorrhages, tissue necrosis and the creation of neovascularization. Juvenile diabetes nowadays is quite a widespread disease resulting in affecting individuals and young age. It is very important for diabetics to regularly control their blood sugar.
Diabetic retinopathy is an insidious disease characterized as one of the most common causes of vision loss (blindness). The main symptoms are listed below:
- fluctuations and blurred vision
- floaters, flashing lights
- shadows in some areas of the visual field
What are the stages of diabetic retinopathy?
- Substrate Retinopathy (non-productive) is the early stage of the disease. At this stage the image of the fundus shows microaneurysms, hemorrhages, exudates and edema on the retina. When the leakage of components from blood to tissues is the most central point of the retina (the macula) then we have macular edema. The above is a result of failure of diabetes in the small vessels (capillaries) of the retina. Considered as a warning stage since the vision is not usually affected significantly
- Proliferative retinopathy (productive) due to poor blood circulation to the retina, areas of low oxygenation are created (ischemia). The eye, responding to such a situation creates new pathological (abnormal) vessels which are very sensitive (have weaker walls), which can break and bleed. The final stage of the productive retinopathy includes vitreous hemorrhage, scarring, detachment, neovascular glaucoma and vision loss
Given the extent of the damage, the main treatments are:
- Photocoagulation with laser: in this process, the laser light beam helps cauterize the bleeding retinal vessels. Repeated shots of the laser prevent abnormal vessel growth. The primary objective of the process is the stabilization of vision
- Intravitreal injections (injections): are the latest development in the treatment of pathological neovascularization and retinal edema. The intravitreal injection is actually an injection within the eye. Essentially a special drug is infused that blocks the action of the VEGF. The VEGF (Vascular Endothelial Growth Factor), is encouraging the development of pathological, abnormal vessels, i.e. neovascularization
- Cryotherapy: where we have extensive blood opacities in the vitreous, laser surgery can not be used until the blood is stabilized or purified. In these cases the “freezing” of the retina may help shrink the abnormal blood vessels
- Vitrectomy: it is the surgical treatment and it is selected in advanced cases of proliferative (productive) diabetic retinopathy. The ophthalmologist performs a surgical intervention of a resection of the hazy vitreous (removal thereof and replacement with a clean solution)
The only certainty is that regardless of the above treatments, the diabetic patient should systematically controls blood sugar levels and keep the medication they have been prescribed. Frequent visits to your eye doctor are necessary.
Watch the educational video with photocoagulation (pascal laser photocoagulator):
What is Central Serous Chorioretinopathy (CSCR) and when does it occur?
The Central Serous Chorioretinopathy (CSCR – Central Serous Chorioretinopathy) is a disease of the macula (the central part of the retina responsible for sharp vision). The disease occurs most often in men than in women, and particularly at the age between 22 and 50. The exact cause of the disease is not fully understood. It is said that the strong stress (stress) is the main cause of the problem. It is due to rupture of linkages between the epithelium pigment cells (pigment layer of the retina). Liquid from the layer of blood vessels, i.e. the choroidal layer of tissue underneath the retina passes through the cracks, thus forming a small retinal detachment, under the macula. In most of cases it is characterized as a benign disease and in a major proportion, it is self-cured (it is limited without treatment after the concentrated serous fluid recedes).
What are the symptoms?
Central serous Chorioretinopathy (or choroidal retinopathy) usually causes a blurring of the central vision of the eye (or a central blind spot in the visual field). The patient may also complain of distorted vision (metamorphopsia) or even “faded” colour perception.
Diagnosis and treatment:
A complete Ophthalmologic monitoring is considered necessary. The control involves the technique of funduscopy (after mydriasis), where there is collection of fluid under the macula. Spectral optical coherence tomography examinations (OCT) & angiography (with fluorescein or indocyanine green) give a detailed mapping of the “suspicious” region of useful conclusions on monitoring and disease progression.
CSCR most of the times (around 94% of patients) does not need treatment, since as it was pointed out, it is self-limited (it regresses). Therapeutic intervention is decided only when the CSCR is not confined within a period of about three months. A large safety therapeutic approach is the application of “cold” laser of photodynamic therapy (PDT). “Thermal” laser (of low intensity) using the technique of photocoagulation (photocoagulation laser) is applied when, through the fluorescein angiography findings, it is found that the fluid leaks away from the central area of the macula, so those are able to “seal”. Several times acetazolamide administration is proposed to accelerate the absorption of subretinal fluid.