Conditions of the retina vary greatly – as do the treatments. But at Optegra, the emphasis that we place on getting to know each patient individually enables us to determine rage exact nature of each case, so that we can develop a tailored programme of care that treats the immediate condition along with any underlying disorders.
What is a Retinal condition?
When light enters our eye, it passes through the cornea, the lens and the vitreous before finally reaching the retina. Here, it is converted to electrical impulses. These electrical impulses are sent via the optic nerve to the brain where they are converted into the bright, colourful images that we see.
In healthy, young eyes the light passes through the eye to the retina unimpeded. However, over time, the vitreous (a clear, gel-like fluid in the globe of the eye) can become opaque. This prevents light from reaching the retina effectively, which can result in visual problems such as hazy vision, ‘floaters’ or macular holes.
What are the treatments for Retinal Conditions?
Optegra plays a leading role in the research and treatment of retinal conditions. Our corrective vitrectomy treatments are among the best in the world. A vitrectomy involves removing the opaque fluid from the eye, allowing a clear passage for light to reach the retina once more. Most retinal conditions begin with this procedure and are then followed by an additional treatment to correct the specific condition. Floater operations, for instance, combine vitrectomy with cataract removal, whereas a macular hole procedure involves coaxing the detached retina back into position once initial vitrectomy has been performed.
Many people will regain their vision without treatment. However treatment is often recommended to prevent another occlusion in either the same eye or the other one. There are a number of potential options available at Optegra.
Retinal Vein Occlusion (RVO)
Retinal Vein Occlusion (RVO) is the result of a blockage of one of the vessels that transports blood out of the eye. The occlusion of a smaller retinal vein is known as a branch retinal vein occlusion (BRVO) whereas Central retinal vein occlusion (CRVO) describes the blockage of the main retinal vein. Such blockage results in leakage from the vessel. If the macular area (the region of the eye responsible for detailed vision) is involved swelling of the macula (macula oedema) may result. This leads to a sudden painless reduction in vision. If the macula is not involved there may be no symptoms or a loss of an area of vision in the periphery. The resultant lack of oxygen to the tissues (hypoxia) due to the vessel occlusion causes the release of a chemical called a growth factor (vascular endothelial growth factor or VEGF). This stimulates the growth of abnormal fine vessels (neovascularization) that are very delicate and also prone to leakage. In certain types of CRVO such vessel growth may cause glaucoma during the first three months following the original blockage
Ozurdex – for macula oedema
If macular oedema is present, the Consultant may recommend Ozurdex treatment. This is a steroid containing implant that can be injected into the vitreous (the gel at the centre of the eye that helps maintain its shape) that is close to the macula. The actual injection only takes a few minutes and can be performed at a later date as a day surgery case.
Ozurdex works by blocking the production of VEGF. It also inhibits the synthesis of prostaglandin: substances that cause inflammation and swelling.
Treatment for a detached retina
Surgery to repair the retinal detachment may be performed in a number of ways. The consultant will discuss the types of surgery available with you and advise you on which is most suitable. Surgical procedures to repair retinal detachment include vitrectomy and scleral buckling.
Vitrectomy involved the removal of part of the vitreous gel that is situated inside the eyeball next to the retina. This can be done through a very small incision. This is followed by the insertion of a gas that may be used in conjunction with dissolvable stitches to keep the retina in the correct position. Laser or freezing procedures then create a scarring effect that in effect walls off the retinal detachment closing up the break.
Scleral buckling involves the stitching of tiny silicone bands or sponge material to the tough outer wall of the eye (sclera) in the area corresponding to the location of the detachment. These substances indent the sclera pressing the retinal break inwards towards the vitreous gel in the centre of the eyeball. This reduces the amount that the vitreous gel pulls on the retina (vitreous traction). It also helps to prevent the movement of liquefied vitreous fluid behind the break, which may otherwise cause it to increase. A vitrectomy may also be necessary and a heavy gas may be injected into the eye to keep the retina in the correct position. Laser or freezing procedures may then be used to create a scarring effect, sealing off the break.
Treatment for macular holes
It may be possible to surgically repair the macular hole. This involves a procedure called a vitrectomy in which the vitreous gel situated close to the retina is removed. The surgeon may then need to remove membranous tissue around the macular hole before injecting a long acting gas into the space left by the excavated vitreous. The gas rises as much as physically possible as it is lighter than air. This property is utilized to aid recovery by the patient sitting with their face down or lying on their front for the majority of the time for approximately two weeks. This posturing causes the gas to settle against and seal the macular hole which enables the natural repair process to take place. The gas does not have to be removed as it gradually disperses during the first couple of months following surgery.