Patient Education Series:Treating Retinal Detachment

What is retina?

The retina is a thin, transparent tissue of light-sensitive nerve fibers & cells. It covers the interior wall of the eye like wallpaper covers the walls of a room. It functions like the film in a camera- light passes through the lens of the eye & is focused onto the retina. The retina “takes the picture” & transmits the image via the optic nerve to the brain.

What is retinal detachment?

It is a condition in which the light sensitive layer of the eye(retina) separates from the underlying eye wall & hence loses its function. It is a serious problem that may occur in any age although it usually occurs in middle-aged or older individuals. It is more likely to develop in people who are nearsighted (myopes) or in those whose relatives have had retinal detachments. A hard, solid blow to the eye may also cause this. If not treated early it may lead to impairment or loss of vision.

How does retinal detachment occur?

It is mainly caused by presence of one or more small tears or holes in the retina. Normal ageing can sometimes cause the retina to thin & degenerate (called lattice degeneration), but most often shrinkage of the vitreous body- the clear gel that fills the center of the eye, is responsible for the causation of retinal tears.

Shrinkage & detachment of the vitreous body is a common event with the age but does not cause any problem in most people. In few eyes that have abnormal strong attachments of the vitreous to the retina, a tear can result. Abnormal growth of the eye, which occurs in myopia or injury to the eye, may also cause the vitreous to shrink. Once a tear is present, watery fluid from the vitreous space may pass through the hole & flow between the retina & the outer wall of the eye. This seperates the retina & causes it to “detach” . The part of the retina that is detached does not function properly & there is a blur or a blind spot in vision.

There are other rare conditions such as tumor, which cause retinal detachment without formation of a hole/tear.

Retinal Detachment symptoms

One may see floating black spots called floaters, & flashes of light in the vision. In most cases, these do not indicate serious problems. But, in some cases, they may be associated with the retinal tears. A comprehensive eye examination by a retinal specialist to check the retina is necessary to determine if retinal tears are present. Such an examination is desirable as soon as symptoms develop because fresh retinal tears may be treatable without surgery, before they lead to a more severe retinal detachment.

Some retinal detachments may begin without noticeable floaters or flashes of light. In these cases, one may notice a wavy or watery quality in the overall vision or the appearance of a dark shadow in some part of the side vision. Further development of the retinal detachment will blur the central vision & create significant sight loss unless the detachment is repaired.

A few detachments may occur suddenly & one may experience a total loss of vision. Similar rapid loss of vision may also develop by bleeding in the vitreous, which happens when the retina is torn.

Diagnosing retinal detachment

A detachment retina cannot be viewed from the outside of the eye. Hence, if symptoms are noticed, a retinal surgeon should be visited as soon as possible. The specialist throughly examines the retina with an instrument called Indirect Opthalmoscope. The instruments bright light & magnification allows the specialist to locate areas of retinal tearing or weakness, which need to be corrected by treatment. Other special diagnostic instruments including special contact lenses, slit lamp etc & Ultrasound may also be used.

How to treat retinal detachment

There is no medical treatment for retinal detachment. If the retina is torn & retinal detachment has not yet occurred, the same may be prevented by prompt prophylactic treatment. Once the retina becomes detached, it must be repaired surgically by a retinal surgeon. Successful re-attachment of the retina consists of sealing the retinal tear & preventing the retina from pulling away from the back of the wall of the eye again. There are several surgical procedures that may be used. The choice depends on the severity of the retinal detachment & the judgment of the surgeon.

There are 3 different techniques of treating Retinal Detachments

1.Pneumatic retinopexy:

In very select group of patients, one may inject a gas bubble in the eye, treat the retinal hole with cryotherapy (freezing) or laser, & then position the eye to enable successful closer of the hole. This is the simplest of the treatment approaches with least intervention. The success of this procedure is about 70% & in case of failure, scleral buckling procedure can be done.

2.Scleral buckling: most other simple retinal detachments are handled by applying a silicone buckle on surface of the eye, thus indenting the walls inside. The retinal hole is treated with cryotherapy(freezing) & nthe fluid that has collected between the retina & the underlying layers is usually removed. The success rate of this surgery is usually 80-90%.

3.Vitreorentinal procedures: For more complex retinal detachments, complicated surgery called vitreoretinal surgery is needed. In this, the diseased vitreous is removed along with abnormal scar tissue. The retina is attached by use of air, gas or silicon oil. The success of these surgeries varies with type of case. Sometimes, multiple surgeries may be indicated in case of recurrence. Where silicone oil is used, it is usually removed after a variable period of time, once the retina is successfully reattached. The final success can be declared only if the retina remains attached after removal of silicone oil.

Obviously, the more complex the retinal detachment, the more complex will be the surgical procedure needed & less will be the cure rate.

Recovery and Post Operative Care:It is important to understand that surgical success & visual recovery need not go hand in hand. The visual recovery depends upon the basic strength in the retina, the duration of retinal detachment & most importantly, the health of the central, most sensitive part of the retina(mascula). Reading fine print needs excellent vision, hence only a percentage of the eyes with complex retinal detachment can regain reading capabilities. More often, mobile vision is retrieved. Failed surgery usually leads to non-recovery of vision & on occasions these eyes may shrink.

The surgery may be done under local or general anesthesia. With gas in the eye, air travel is restricted. Eye drops or ointment may have to be instilled for 6-8 weeks & glasses are prescribed at final examination.

With simple buckling surgery, vision may start recovering in a few days , but final vision is known after 6 weeks. With more complex vitreorentinal surgeries, it takes longer time for vision to improve & stabilize.

Patients with symptoms of retinal detachment require prompt attention by a retinal surgeon, who will throughly examine & advice about the need for treatment. It is important for persons with significant myopia or with family history of retinal detachment to have periodic eye examination. Early detection of changes in the vitreous or retina can be diagnosed & potential retinal detachment prevented.

To schedule an appointment with our eye care consultants at Wockhardt Hospitals please email us at enquiries@wockhardthospitals.net