WHAT IS IT

The retina is the important innermost layer of nerve cells at the back of the eye which sends information to the brain via the optic nerve to enable us to see.

A retinal detachment occurs when the retina separates from the outer layers of the eye (choroid). This is an emergency as it leads to visual impairment and possible blindness, if not treated in time.

 

CAUSES

  • Retinal tears or holes are the commonest cause of retinal detachment.
    These result when the vitreous gel shrinks and pulls on the retina, which then breaks, allowing liquid from the vitreous gel to flow into and accumulate in the space between the retina and the choroid.
    As the liquid collects, the retina ‘peels away’ from the underlying choroid, resulting in a retinal detachment. The areas where the retina is detached  lose their ability to perceive light, thus affecting vision.Risk factors for developing retinal tears/ holes include:

    • High myopia
    • Diabetes
    • Cataract surgery
    • Eye conditions eg uveitis, tumours
    • Eye injury
    • A family history of retinal tears or detachment

SYMPTOMS

Retinal detachment is painless but warning symptoms almost always appear before it occurs. These include:

  • Seeing a sudden increase of floaters
  • Seeing light flashes that persistently occur
  • Seeing a dark shadow or ‘curtain’ over part of the visual field
  • Sudden blurred or total loss of vision

Any of these should prompt an urgent evaluation by an eye doctor to save and preserve vision.

 

TREATMENT

Surgery is the only effective treatment for retinal tears, holes and detachment. Early intervention to repair tears and holes before the retina has detached or before the central part (macula) of the retina is affected has the best chances of preserving sight.

Surgery for retinal tears

  • Laser photocoagulation
    A laser beam is directed into the eye through a special contact lens or ophthalmoscope to seal the retinal tear. This cause scarring around the tear which then ‘welds’ the retina to the underlying tissue.  No incision is needed and it causes less irritation than cryopexy.  Laser photocoagulation is done as an outpatient procedure.
  • Cryopexy
    This procedure is suitable for tears which are not easily accessible to the laser ( eg around the retinal periphery ) and uses intense cold to freeze the retina around the tear. A freezing probe is applied to the outer surface of the eye over the retinal defect. This causes a delicate scar which then helps secure the retina to the eye wall.

Surgery for retinal detachment

  • Pneumatic retinopexy
  • Scleral buckling
  • Vitrectomy

The type, size and location of the retinal detachment will determine which of these procedures is most suitable. Often done in conjunction with laser photocoagulation or cryopexy, the aims are to close up any retinal holes, reduce the tug on the retina from a shrinking vitreous and to flatten the detached retina.

PROGNOSIS

Over 90% of retinal detachments can be reattached by these surgical techniques. However, on occasion, more than one operation may be required. The degree of vision that returns is dependent on many factors. As such, close monitoring by the eye surgeon is necessary for the best possible outcome.