Retinal surgery

Symptoms and causes

Holes or tears in the retina are usually caused by degenerative changes in the retina or by a vitreous body detachment that pulls on the retina. Sometimes small blood vessels are damaged, leading to bleeding into the vitreous body. These changes in the eye do not cause pain, but patients see distinct flashes of light caused by the vitreous body pulling on the retina. If bleeding occurs, it appears to the patient like a kind of dark rain; if the bleeding is more severe, this can lead to a significant impairment of vision. When holes or tears occur in the retina, fluid gets behind it. This in turn causes the retina to detach itself from the underlying tissue.

Exudative (fluid-induced) retinal detachment is a form of the condition in which fluid from the choroid vessels flows between the two layers of the retina. This may cause the two layers to separate from each other. This form of retinal detachment usually occurs through inflammation of the choroid or tumours. In many cases, a disease of the vitreous body is also the cause of damage to the retina. Inflammation can cause damage to the retina too. However, short-sightedness of more than three dioptres, cataract surgery, previous injuries to the eye, a family history of retinal detachment, blunt blows to the eye or long-term diabetes are also risk factors for retinal detachment.

The clearest indications of retinal detachment include:

• sudden flashes of light in the eye, which can also be seen when the eyes are closed,
• swarms of black spots in the eye (like soot raining down or a swarm of black mosquitoes),
• a restricted visual field, not unlike a black shadow or curtain, and
• general deterioration of vision.

It is important to stress that if you experience the initial symptoms of retinal detachment, you need to act quickly, as you will usually need to undergo surgery at short notice in such cases to reattach the retina and ensure an oxygen supply to the centre of the retina. The earlier an ophthalmologist is able to detect a detachment of the retina, the less likely the a surgical procedure or damage to your vision will be. Because if no treatment is given, or if treatment is too late, the damage to the eye is usually permanent and irreversible. This results in a significant deterioration of vision, including blindness.

Treatments

Laser therapy

Neither a tear nor a detachment of the retina can be controlled with medication. If the retina is torn but not yet detached, the affected eye can be treated using a special laser (photocoagulation) or a cold probe (cryopexy). Lasers or cold probes trigger an inflammatory reaction at the site of the injury, causing the tissue to scar and thus “sealing” the hole in the retina (scarring to isolate the issue). This usually prevents complete detachment of the retina.

Operation

However, if the retina has already detached, the patient should be operated on by a specialist eye surgeon as quickly as possible. Which method is used depends on the form of retinal detachment on the one hand and on how far the detachment of the retina has progressed. The aim of the operation is always to reattach the detached retina and to correct the factors that triggered it, such as changes to the vitreous body.

In the case of a single hole or tear, a dent is made in the eyeball in the area of damage with a foam inlay, which is sewn onto the sclera from the outside. If there are several holes, a so-called scleral buckle operation must be performed. This involves placing a band around the entire eyeball, which is then tightened by a certain amount to cause a degree of circular constriction. The fluid is removed by puncturing the space containing the fluid between the retina and the choroid. The holes or cracks in the retina now lie against the inlay or tape and are sealed in the process. This procedure lasts between 30 and 60 minutes and can be performed under local or general anaesthesia.

The vitreous body may also be removed to counteract retinal detachment (known as vitrectomy). This operation can also be performed under local anaesthesia and again lasts between 30 and 60 minutes on average. During vitrectomy, the fluid from the vitreous body is sucked out and replaced with a special fluid (e.g. silicone oil, gas or Ringer’s solution). This displaces the accumulated fluid between the layers of the retina and thus joins them back together.

However, if retinal detachment is caused, for example, by a tumour of the eye, the tumour must be treated to stop any further retinal detachment. Tumour treatment includes laser and chemotherapy as well as irradiation of the eye.