Vitreoretinal Surgeries

Retinal     detachment

Patients with retinal detachment  who apply to the Vitreoretinal department of the Eye Center after S.V.Malayan  , can get high-quality and modern medical care. Retinal detachment is a disorder of the eye in which the retina separates from the layer underneath.Symptoms include an increase in the number of floaters, flashes of light, and worsening of the outer part of the visual field. This may be described as a curtain over part of the field of vision. Retinal detachment leads to a dramatic reduction of vision and can produs blindness, so immediate therapeutic intervention is required for restoring  the anatomical structure of the retina and to avoid  nerve cells  loss. According to the mechanism there are 3 types of retinal detachment.  1.Rhegmatogenous retinal detachment – A rhegmatogenous retinal detachment occurs due to a break in the retina (called a retinal tear) that allows fluid to pass from the vitreous space into the subretinal space between the sensory retina and the retinal pigment epithelium. 2.Exudative, serous, or secondary retinal detachment – An exudative retinal detachment occurs due to inflammation, injury or vascular abnormalities that results in fluid accumulating underneath the retina without the presence of a hole, tear, or break. In evaluation of retinal detachment it is critical to exclude exudative detachment as surgery will make the situation worse, not better. Although rare, exudative detachment can be caused by the growth of a tumor on the layers of tissue beneath the retina, namely the choroid. 3.Tractional retinal detachment – A tractional retinal detachment occurs when fibrous or fibrovascular tissue, caused by an injury, inflammation or neovascularization, pulls the sensory retina from the retinal pigment epithelium.

Treatment 

There are several methods of treating a detached retina, each of which depends on finding and closing the breaks that have formed in the retina. All three of the procedures follow the same three general principles:

-Find all retinal breaks

-Seal all retinal breaks

-Relieve present (and future) vitreoretinal traction

Cryopexy and laser photocoagulation Cryotherapy (freezing) or laser photocoagulation are occasionally used alone to wall off a small area of retinal detachment so that the detachment does not spread. Scleral buckle surgery. Scleral buckle surgery is an established treatment in which the eye surgeon sews one or more silicone bands (or tyres) to the sclera (the white outer coat of the eyeball). The bands push the wall of the eye inward against the retinal hole, closing the break or reducing fluid flow through it and reducing the effect of vitreous traction thereby allowing the retina to re-attach. Often subretinal fluid is drained as part of the buckling procedure. The buckle remains in situ. The most common side effect of a scleral operation is myopic shift.

Pneumatic retinopexy.

This operation is generally performed in the doctor's office under local anesthesia. It is another method of repairing a retinal detachment in which a gas bubble (SF6 or C3F8 gas) is injected into the eye after which laser or freezing treatment is applied to the retinal hole. The patient's head is then positioned so that the bubble rests against the retinal hole. Patients may have to keep their heads tilted for several days to keep the gas bubble in contact with the retinal hole. The surface tension of the gas/water interface seals the hole in the retina, and allows the retinal pigment epithelium to pump the subretinal space dry and "suck the retina back into place". This strict positioning requirement makes the treatment of the retinal holes and detachments that occurs in the lower part of the eyeball impractical. This procedure is usually combined with laser photocoagulation.

Vitrectomy

Vitrectomy is an increasingly used treatment for retinal detachment. It involves the removal of the vitreous gel and is usually combined with filling the eye with either a gas bubble (SF6 or C3F8 gas) or silicone oil . An advantage of using gas in this operation is that there is no myopic shift after the operation and gas is absorbed within a few weeks. Silicone oil, if used, needs to be removed after a period of 3–6 months depending on surgeon's preference and patient’s eye status. Silicone oil is more commonly used in cases associated with proliferative vitreo-retinopathy (PVR).

Diabetic retinopathy

Diabetic retinopathy is a major cause of blindness in the world today.

Taking into account the importance of the problem, since 2010, under  the guidance of Prof. A.H.Vardanyan, the Head of the Department of Vitreoretinal  surgery of the Eye Center  after S.V.Malayan created a Fighting Councils for the diabetic patients and also Primary Diabetic Surveillance Cabinet.

Diabetic retinopathy is classified as non-proliferative and proliferative. The disease is expressed as insulin dependent patients , as well non-insulin dependent patients. In the early stages of diabetic retinopathy can be without symptoms .As the condition progresses, patients notice  spots or dark strings floating in your vision (floaters),blurred vision,fluctuating vision,impaired color vision,dark or empty areas in  vision,vision loss. Non-proliferative diabetic retinopathy is initially characterised by microaneurysms ,expanded capillaries,point and linear hemorrhages,հard exudates in nerve layers,clinically significant macular edema. During severe non-proliferative diabetic retinopathy shown panretinal laser photocoagulation and  intravitreal injection of AntiVEGF - Avastin,Lucentis and Eylea. Proliferative diabetic retinopathy  is expressed  with new vessels on the optic nerve and else way .These  new vessels use the posterior vitreous as a scaffold. There is a high risk of hemorrhage from these vessels causing diabetic hemorrhages into the vitreous and subhyaloid spaces. There is also a proliferation of fibrous tissue along with neovascularization. The regression of the vessels with persistent fibrous proliferation can lead to complications including tractional retinal detachments. After having  diabetic tractional retinal detachment shown pars plana vitrectomy with removing fibrous tissue , panretinal laser photocoagulation and endotamponade with aire,gas or silicone oil. For Pars Plana vitrectomy existe modern selection between 20 G,23G,25G and 27G. Early treatment allows better control of the course of the disease. After a right treatment of diabetic retinopathy, a long-term stabilization of the condition is often observed. Panretinal laser photocoagulation improves vision on 17%patients. Proper control of blood glucose and blood pressure slows down the development of diabetic retinopathy and macular edema. In case of early diagnosis and correct treatment, it is possible to prevent further complication of the disease.