Retinal Detachment

Retina : is the innermost coat lining the inside of the back part of the eyeball. It is a thin sheet of nerve tissue, which turns light into electrical signal producing image of the object focused Retina can be compared to the film in a camera.

Vitreous : is a jelly-like material that fills most of the space inside the eyeball. Vitreous is normally loosely adherent to the retina providing support and nutrition to the retina. With age the Vitreous often liquefies & separates from retina. This is more likely to occur, &. Occurs earlier in eyes that are myopic (minus numbers). It can also occur after injury to eye or inflammation in the eye or following eye surgery.

What is Retinal Detachment?

The Separation of retina from the back part of the eye is called Retinal detachment. Retinal detachment is a serious eye problem that may occur at any age. If not treated early, retinal detachment may lead to very poor or total loss of vision.Causes of Retinal Detachment : Most retinal detachments are caused by presence of one more small tears or holes in the retina.

Normally, the vitreous is attached to the retina in several places. With aging, changes occur in the vitreous causing it to shrink. During this process occasionally it may pull a piece of retina with it, producing a tear or hole in the retina. This is more likely to develop in people who are myopes (near sighted) or those whose close relatives have had retinal detachments. A direct blow to the eye may also cause retinal tear leading to detachment. Tear may also develop in or adjacent to thin areas in retina called “lattice retinal degeneration”.

Once a retinal tear is present, fluid from vitreous may pass through the hole and separate the retina from the back of the eye causing it to detach.

Symptoms of Retinal Detachment : Many patients notice black spots or cobweb like objects (floaters) and/or flashes of light in their vision before the retina detaches.Floaters & flashes are due to normal aging changes in vitreous and in most cases do not indicate any serious problem. However, sudden appearance of many floaters or flashes may indicate substantial shrinkage of vitreous with tears in retina and requires a thorough retinal evaluation.

Some retinal detachments may begin as a gradually enlarging dark area which gives a feeling of curtain coming down or a shade being drawn in front of the eye. Once the detachment affects the central part there is marked reduction in vision.

Diagnosis : A detached retina cannot be seen from outside of the eye. If symptoms are noticed, an ophthalmologist (preferably retinal specialist) should be visited at the earliest.The retina is checked thoroughly by an instrument called Indirect Ophthalmoscope Sometimes other specialized diagnostic procedure such as Ultra sonography may be needed.

Treatment : If the retina is only tom & detachment has not occurred, further problem may be prevented by prompt treatment by producing controlled scar around the tear either by laser or cryopexy. Once the retina is detached, it has to be repaired surgically.

Laser photocoagulation : When there are only retinal tears with little or no detachment, the tears can be sealed by laser. Laser burn produces scars that seal down the edges of the tear and prevents fluid from passing under the retina. This is done as an outpatient procedure and does not need any surgical incision.

Cryopexy (Freezing) : This is another method of producing a scar to seal the retinal tears. Cryopexy is also an outpatient procedure but requires topical/local anaesthesia.Once there is significant amount of detachment, some form of operative procedure is required. The type of operation depends on the extent and position of the detachment.

Floaters Flashes

Scleral Buckling : In this, the retinal tears are located and treated with freezing (Cryo) technique to produce a scar to seal them tear. A silicone piece is sutured to the White of the eye (sclera) to support the retina in the area of tears. This is called ‘buckling’. Fluid may or may not be drained from under the detached retina. Gas may also be injected inside the eye to support the retina temporarily from inside.

Pneumatic Retinopexy : This is another type of surgery in which cryo or laser treatment is done to seal the retinal tear followed by injection of a gas bubble inside the vitreous Cavity. In this nothing is sutured on the outside of the eyeball. The patient has to keep his head in a particular position so that the gas bubble pushes the retina against the wall of the eyeball. The advantage is that it is a relatively minor procedure and in case it fails scleral buckling or vitreous surgery can be performed. The disadvantage is that not all cases can be treated by this and chances of success is slightly less than with scleral buckling.

Vitrectomy : In case of progressive shrinkage of vitreous and/or development of growth of excess of scar tissue on the surface of retina, the sclera buckling surgery may fail. This is because the shrinking vitreous and the scar tissue pulls the retina causing it to redetach. This is called Proliferative vitreoretinopathy (PVR). Some times, the detachment may be more complex with shrunken vitreous and puckered retina due to long standing retinal detachment.In such complicated cases it may be necessary to use a technique called vitrectomy. In this 3 small opening are made in the eyeball. Through one opening, fluid is put in the eye while one opening is used to introduce fiber optic light to illuminate the inside of the eye. The third one is used for introduction of instrument (vitreous cutter), which cuts and removes the shrunken vitreous ft the instruments used to peel scar tissue from the surface of retina. At the end of surgery, laser or cryo is done and the vitreous cavity is filled fluid ,gas, or silicone oil, depending on the need.

Results : Success depends on many factors.

Incase of fresh detachments about 80% to 90% (8 or 9 out of 10) can be reattached by modern surgical techniques. Occasionally, more than one operation may be needed. In case of old retinal detachments or fibrous tissue on the retina the chances of success is somewhat less.

Successful reattachment does not necessarily mean fully restored vision. Vision depends on whether, and for how long the macula was detached prior to surgery. If macula was detached, normal vision is rarely achieved. However, if the retina is reattached successfully, the vision usually improved and blindness have been prevented. Also, the vision usually improved gradually over period of months.

Post-operative Period: The surgery is usually performed under local anaesthesia. The patient can be discharged few hours after the surgery. The eye will be red and swollen for some days. Watering is also common in the early postoperative period. Mild pain may be there, but severe pain is unusual. The eye pad is removed on second day. Tablets and eye drops have to be used a prescribed. Sometimes a particular head posture is advised depending on the need.

Complications: As with any other surgery, some complications may occur. Scleral buckling surgery may cause bleeding under the retina, vitreous haemorrhage, cataract, glaucoma, double vision, infection of buckle etc. However, retinal redetachment is the most commonly occurring problem.