The retina is the innermost tissue of the eye, consisting of nerve cells that are sensitive to light and transmit perceived data to the brain. The optical image formed in the eye is converted into electrical signals by the retina, and these signals are processed in the brain to obtain the sense of vision.

Age-Related Macular Degeneration 

Metabolic waste materials accumulate in the retina with aging. As these accumulations increase, they cause deterioration in the retina, leading to degeneration of retina tissue. While the incidence rate in the society is approximately 2% at the age of 50, the incidence rate increases to 50% by the age of 85.

Age-Related Macular Degeneration Risk Factors

• Aging
• Family history (genetic transmission 20%)
• Gender (More common in women)
• Smoking
• Sunlight
• Fat-based diet
• Low intake of Omega 3 – 6 and vitamins in the diet

Age-Related Macular Degeneration Symptoms

The main symptoms are decreased vision and a gradually growing visual field defect at the center of the visual field, distorted vision, seeing objects larger or smaller than normal and not being able to see the exact point being looked at.

Types of Age-Related Macular Degeneration

There are two types of age-related macular degeneration;

• Dry type
• Wet type

In dry-type age-related macular degeneration, the deposits formed in the visual center cause deteriorations in the retina. The level of vision may not change or may gradually decrease over the years.

Wet-type age-related macular degeneration is the most common cause of vision loss. In wet-type, new and weak-structured vascular development occurs under the retina. These new vessels threaten vision by causing edema and bleeding in the retina. If this condition continues for a long time, the cells in the retina are damaged causing and to permanent vision loss.

Treatment of Age-Related Macular Degeneration

Antioxidant substances and vitamins that support retinal metabolism are used in patients with dry-type age-related macular degeneration. The aim of this supportive treatment is to stop or slow down the progression of age-related macular degeneration.

Injections of medication into the eye are performed for edema and bleeding in patients with wet-type age-related macular degeneration. In intraocular injection treatment, medications that reduce the formation of new vessels are injected into the eyeball cavity. The procedure is not a painful. After the local anesthesia of ocular surface with eye drops, medication is injected into the eye with a very thin needle. The total duration of the injection takes 2-3 seconds.

Retinal Detachment

Retinal detachment can be described as the separation of the retina from its anatomical position. It is observed at a frequency of approximately 1 in 10.000 people and seriously threatens vision. It occurs more frequently in middle age and older but can occur at any age. It can cause partial or complete vision loss, if left untreated.

Retinal Detachment Causes and Symptoms

Retinal detachment mostly develops due to tears or holes in the retina. It is most commonly observed in highly myopic people due to the elongation of the eye. The retinal layer stretches, thins and begins to deteriorate as the anterior-posterior diameter of the eye increases. In some familial or degenerative diseases and some infections, thinning and deterioration may also occur in the retina. Aging causes shrinkage in vitreous and shrunken vitreous pulls the degenerated retinal areas and may cause retinal tear and hole. 

The patient  perceives the shrinkage of vitreous and tractions in the retina as “light flashes, flashing lights”. These flashes can sometimes be short-lived, and sometimes they can last for days. In some patients, they may not be felt at all.

If a vessel artery passes through the retinal tear or hole area, sometimes this vessel can also rupture and cause bleeding inside the eye. This situation is perceived by the patient as “soot rain” or dark spots.

The retinal area that is separated from its proper anatomical position loses its visual function and the patient feels a loss of vision in the form of blurring and black spot. Sometimes, when the retinal detachment does not affect the macula (the eye’s visual center), the patient may not notice any symptoms since it will not affect central vision, but it can be detected during examination. Retinal detachment is rarely limited to a local area, but is mostly progressive. When the macula (the eye’s visual center) detaches, central vision is lost.

Blunt or penetrating trauma to the eye can cause sudden retinal detachment. In diabetes mellitus and some degenerative diseases, fibrotic bands that pull the retina may form in the vitreous and detachments may develop due to traction. In addition, retinal detachment may develop without any tear in the eye in some infections and tumors.

Retinal Detachment Treatment

If retinal tears or holes can be detected before retinal detachment develops, they are treated with argon laser. Some thin and deteriorated areas that may cause tears in the future can also be secured with argon laser. Repair of tear and degenerated areas with argon laser is a painless procedure. Ocular surface is anesthetized with an eyedrop. The area around the tear or hole and degenerated areas is coagulated with 2-3 rows of laser spots. 

If retinal detachment has developed, vitrectomy surgery is performed for treatment and silicone or gas tamponade is applied to keep the retina in the desired anatomical position. While gas tamponade is absorbed and disappears on its own, silicone tamponade is removed from the eye with a second surgery after the intraocular healing is complete.

What is Diabetic Retinal Disease?

Diabetes can cause cataracts, glaucoma and most importantly diabetic retinal disease in the eye, leading to decreased vision. One of the most common causes of vision loss between the ages of 20-65 in the world is eye diseases that develop due to diabetes. The probability of developing eye damage in diabetic patients is around 20% in 10-year diabetics and 80% in 30-year diabetics. 

Diabetic retinal disease is a disorder that affects the vessels in the retinal layer inside the eye. It causes blockages and leaks in the vessels, causing deterioration in the nutrition and structure of the retinal layer.

It is classified into three main stages:

• Non-proliferative period
• Proliferation (new vessel formation) period
• Advanced diabetic eye disease

Non-Proliferative Period 

Retinal vessels show some deteriorations including narrowing, expanding and forming microaneurysms. Blood or fluid begin to leak from these deteriorated vessels. Thus, accumulations called edema and exudate form in the retina. This period is considered as the precursor of events that may endanger vision. In some cases, fluid leak can accumulate in the macula (center of vision) and can impair vision. This condition is called macular edema and should be treated quickly.

Proliferation (New Vessel Formation) Period

The narrowed and blocked retinal vessels cannot supply oxygen to retinal tissues. In these areas, new and unstable vessel formations (neovascularization) and fibrotic membrane formations (fibrous proliferation) occur. The newly formed vessel structure is not stable and is prone to bleeding and leakage. The fibrotic membrane can impair vision by covering or shrinking the macula. Problems need to be treated quickly.

Advanced Diabetic Eye Disease

The movements or shrinkage of the vitreous begins to pull new vessels and fibrotic membrane formations. The new vessels, which are already unstable, bleed and fill the inside of the eye (vitreous hemorrhage). The pulled fibrotic membranes also cause tear and damage to the retinal tissue (retinal detachment). In addition, new vessels can affect the ocular fluid outflow (aqueous humor) and increase intraocular pressure (neovascular glaucoma).

Treatment in Diabetic Eye Disease

Treatment of diabetic eye disease varies according to the stage of the disease. In the non-proliferative period, eye disease findings can regress with good diabetes mellitus control. In the initial stage, laser or intraocular injection treatment is applied depending on the location of the retinal edema. In the proliferation period, laser treatment or intraocular injection treatment is applied depending on the location and prevalence of the newly formed vessels.

Argon laser treatment is a painless procedure. The pupils are dilated with eyedrops. Laser is applied in two ways in diabetic eye disease. If there is only local damage or edema, laser is applied to that area only. If the damage is not limited to one area, laser is applied to the entire retina except the macular area for several sessions. The only thing the patient feels is blue-green flashes of light during laser application.

Injections of medication into the eye are performed for edema and bleeding in patients with wet-type age-related macular degeneration. In intraocular injection treatment, medications that reduce the formation of new vessels are injected into the eyeball cavity. The procedure is not a painful. After the local anesthesia of ocular surface with eye drops, medication is injected into the eye with a very thin needle. The total duration of the injection takes 2-3 seconds.

In advanced diabetic eye disease, the treatment is surgical if there is bleeding, retinal detachment or fibrotic bands that endangers vision.

It should not be forgotten that the effectiveness of eye treatments will be limited unless good diabetes mellitus control is achieved at any stage of diabetic eye disease.