Retinal Detachment

What is a retinal detachment?

The retina is a thin layer of light sensitive cells lie at the back of the eye. It is attached to the gel in the eye – know as the vitreous. As we get older the vitreous detaches from the back of the eye. As it detaches the gel falls forward and pulls on the retina. Many patients experience flashing of lights at this stage as the retina is stimulated by the gel. If there is a weakness in the retina a retinal break or tear forms. Fluid can pass through the retinal break and under the retina; this separates the retina from its blood supply and it stops working. At this stage a patient will often see a dark shadow in their peripheral vision, which can enlarge fairly rapidly over a few days. Without urgent treatment vision is invariably lost permanently.

What is the difference between a macular on and a macular off retinal detachment?

The macula is at the centre of the retina and gives us focused distance and reading vision. If the central part of the retina, the macula, becomes affected, then the central vision drops rapidly. It also has an effect on the long term visual outcome. Macular off retinal detachments generally cause permanently reduced or distorted vision.

Who gets retinal detachments?

Retinal detachments generally occur in patients around the age of 60. Short sightedness and injury are also causes, and there are some families who have a genetic susceptibility to retinal detachment.

What is the treatment?

There are two main operations to re-attach the retina. The main one is a vitrectomy where the vitreous gel is removed, the fluid under the retina is drained, laser therapy is applied to re-attach the retina, and a large bubble of gas or oil is inserted to keep the eye stable. This can be done under a local anaesthetic with sedation if needed. The other type of operation uses a silicone buckle, and freezing therapy to the wall of the eye, to close the break in the retina. As the retina is such a delicate tissue, there is a relatively high failure rate, of 10-20%. A further operation is relatively common but need not permanently affect the vision.

What happens after surgery?

Immediately after surgery, the eye will be padded and kept comfortable. Patients may be asked to take some Diamox tablets to control post operative pressure rises. The eye should be examined the following day and post operative drops (Tobradex and Timolol) are usually prescribed. If a gas has been used during surgery, a patient will not be able to see well from the eye for at least two weeks. Patients should not travel by air or have a general anaesthetic as either could cause blindness.

What are the possible complications of detachment surgery?

In general retinal detachment surgery is successful in 80-90% of patients. However the retina is a very thin tissue and can detach again. This happens typically in the first month when the gas bubble has been reabsorbed. If this happens more surgery is necessary to re-attach the retina. Vision may be lost during surgery through bleeding and scarring of the macular area. Cataracts also form in the majority of cases, which usually can be removed successfully. Other complications include, raised eye pressure and squint, however these occur relatively infrequently.