PORT ELIZABETH OPHTHALMOLOGIST’S

EPIRETINAL MEMBRANE PEEL SURGERY

Your Doctor has advised you to undergo elective retinal surgery for

  • EPIRETINAL MEMBRANE SURGERY

INFORMATION ON EPIRETINAL MEMBRANE PEEL SURGERY

An epiretinal membrane is a thin surface membrane which contracts and leads to wrinkling of the retina. This causes distorted vision, poor vision and a black spot in the center of your vision.

The objective of epiretinal membrane surgery is to peel the membrane off the surface of the retina. This is achieved by removing the gel in the cavity of the eye (Vitrectomy) and then peeling the inner surface layer of the retina (Internal limiting membrane). With modern retina surgery techniques, the success rate for this surgery is more than 90%. Unfortunately, successful anatomic removal of the retina membrane does not always equate to good vision recovery. The amount of vision that recovers is related to the size of the membrane, the amount of scar tissue present and the duration of the membrane. Final vision improvement can often take up to 9 months to recover.

Modern retinal surgery has evolved to become a very safe and efficient procedure with low complication and side-effect risks. By nature of any procedure there are certain complications that can occur. It is estimated that problems (Complications) occurs in less than 8% of cases which still makes this is comparatively safe procedure.

This document will outline some of the more common problems encountered – it is important that you study these carefully and ask your doctor any follow-up questions as needed.

The procedure:

  • The surgery is done under regional or general anesthesia
  • A system of ports is used to allow instruments safe entry into the eye cavity
  • These ports are removed at the end of the procedure
  • The first step is to remove the vitreous gel that fills the cavity
  • This is done with an instrument which is called a vitreous cutter – it aspirates / “sucks” the gel whilst simultaneously cutting the aspirated gel as it enters the instrument
  • Once the gel is removed the surface retinal layer is stained with a colourant and the inner layer of the retina peeled along with the membrane to relieve traction on the retina.
  • At the end of the procedure retinal strengthening laser is applied to the edges of the retina
  • The eye is then filled with gas to support the retina – this is self-absorbent and will leave the eye after a 2-3 weeks depending on the type of gas used
  • Occasionally a stronger support is needed for the retina – medical silicone oil is then placed in the eye cavity to support the retina. This will need to be removed again after a few months.
    • Occasionally it is needed to posture with your head in a certain specific position for a few days to aid retinal recovery – your eye surgeon will communicate this with you.

The potential complications:

  • Cataract formation
    • If you still have your natural lens then it is highly likely that a cataract will ensue over time
    • This can happen within weeks after the surgery or many years later
    • This is due to the turbulence in the gel (Closely approximated to the lens) during surgery
    • A cataract however is now a minor problem and can be corrected with a simple 10-minute procedure
    • It is now standard procedure to remove the lens of the eye in most patients older than 45 years who undergo retinal surgery
  • Bleeding
    • This can happen during the operation and will be managed appropriately by the surgeon
    • It can happen after the surgery from one of the wounds – in some cases ((uncommon) it might be necessary to wash the eye out with a second surgery
  • Infection
    • This is very uncommon (estimated 1 in 5000 cases)
    • The infection would probably require urgent intervention with antibiotic administration to the eye and often a repeat surgery to wash the infection out of the eye
  • Retinal Injury
    • Retinal tears can occur during the surgery or after the surgery
    • A retinal tear occurs in weak areas of the retina
    • A retinal tear has a 50% chance of leading to retinal detachment
    • The highest risk is in the first 18 months after surgery
    • Intraoperative retinal tears are lasered and treated with a temporary gas or oil tamponade
    • Post-operative tears are treated with retinal laser and or repeat surgery
    • Retinal detachment after any retinal procedure occurs in 3-8% of cases as seen with studies across the world
    • A retinal detachment can be vision threatening and lead to permanent blindness
  • Glaucoma / High Eye pressures
    • This problem is rather common in retinal surgery
    • It is not uncommon to develop temporary raised eye pressures in the first few weeks after surgery
    • This is usually treated with drops or tablets to control the eye pressure and resolves as the healing completes
    • In uncommon cases the eye pressure can remain elevated and the patient will then be started on permanent eye drops to control his eye pressures – it might even become necessary to treat the eye pressure problem with surgery or lasers
    • It is important that patients who have had retinal surgery should continue lifelong checkups of their eye pressures as this problem can develop at any time (Even late after surgery) following retinal surgery
  • Vision loss
    • Permanent vision loss can happen with retinal surgery
    • This is extremely rare (< 0.5% incidence)
    • This can happen due to a patient having poor blood supply to the eye from underlying vascular problems (like diabetes and hypertension) which is then worsened by the nature of surgery to the core of the eye
  • Failure of effect
    • The retina is a tissue extension of the brain and as such brain tissue
    • In most cases the retinal membrane is removed completely – in some cases it is not possible to remove the full membrane if it is too tightly attached to the deep retinal layers
    • It could potentially be necessary to repeat surgery again with a secondary attempt to peel remaining membrane – this is very uncommon
    • Depending on the presenting status of the membrane and retina it is difficult to predict the visual recovery. As a rough rule of thumb 75% of cases show significant improvement, 20% of cases show only minor improvement or no improvement at all despite successful peeling of the membrane. 5% of cases can show worsening of vision.
    • The same is possible for distortion of vision – in some cases the membrane is peeled successfully but there is persistent distortion such as image magnification or warping of lines. This is due to inherent retinal damage from a long standing retinal membrane.

Other important things to keep in mind:

  • It is contraindicated to travel in an airplane or to high altitude in a car(over a mountain pass for example) with gas or air bubble in your eye
  • Preferably, do not book or plan any air travel for at least 8 weeks after your planned surgery
  • Remember that if you receive intraocular gas post-operatively your vision will be very poor until the gas resorbs by itself – it is also common to have double vision once the bubble is at 50% in your eye – this lasts a few days and recovers spontaneously
  • Post-operative drops are always prescribed after the operation and should be finished and only stopped on the instructions of your surgeon
  • Remember again that the retina is part of the brain tissue, and that recovery of vision can be very slow – the full visual outcome is only ascertained 9 months after the surgery