Tag: macular hole

What Causes a Macular Hole?

Retinal surgery sometimes uses injection of gas into the eye, especially when you have a macular hole.

Causes of a macular hole are discussed in this article and explained in the embedded video.

A macular hole is a hole at the very center of the retina. The retina is the layer of tissue that lines the inside of the eye and it contains millions of light-sensitive cells that receive and send visual information to the brain.

The macula portion of the retina contains the highest concentration of light-sensitive cells and is responsible for high-resolution, detailed central vision and most of our color vision.

Holes in the macula can be caused by injury, but most macular holes occur in people over the age of 60 and are caused by the vitreous gel in the eye pulling on the macula. These are called idiopathic macular holes and are, for reasons unknown, more common in women than men.

The Role of the Vitreous in Macular Holes

The vitreous contains millions of microscopic fibers that attach to the retina. As people age the vitreous slowly shrinks and pulls away from the retina’s surface and natural fluid fills in the area where the vitreous contracted. This is normal and usually causes no problems beyond possibly seeing “floaters” in your visual field from time to time.

However, in some cases the vitreous is so firmly attached to the retina that when it pulls away it can tear the retina slightly and cause a hole to form. Small holes sometimes heal on their own, but they can also gradually increase in size causing vision loss.

Other Causes of Macular Hole

The following additional conditions can cause a macular hole to develop:

  • Blunt trauma to the eye
  • Diabetic eye disease 
  • High degree of myopia (nearsightedness)
  • Macular pucker—caused by scar tissue on the macula

Symptoms of a Macular Hole

In the early stages there may be a slight distortion or blurriness in central vision. As the hole increases in size, straight lines and objects look bent or wavy, vision becomes increasingly blurrier and a dark spot may appear in the center of your vision.

Treatment of Macular Holes

A surgery to remove the vitreous gel (vitrectomy) and prevent it from continuing to pull on the retina is currently the best way to repair a macular hole. After the removal of the vitreous gel, a bubble containing a mixture of air and gas is put into the eye to prevent subretinal fluid from seeping behind your retina and destabilizing the healing process.

The gas bubble will slowly dissipate and be replaced with aqueous humor produced by your eye. You may be asked to keep your head in a face-down position for several days to keep the bubble in place. CAUTION: As long as any of the gas bubble remains in your eye you must not fly in an airplane because the bubble can expand in the reduced pressure of the cabin causing severe pain and possible loss of sight.

Another potential treatment for some patients with macular holes is the injection of an antiplasmin inhibitor that inactivates plasmin, an enzyme that breaks down the fibrin in blood clots.

Success Rate

The vitrectomy success rate is over 90% with patients regaining most of their lost vision. The gas bubble starts to shrink 7 to 10 days after the vitrectomy, but it takes about 6 to 8 weeks for the gas bubble to be totally absorbed. Vision will continue to improve during that 6 to 8 week time.

Complications

In less than 10% of cases the vitrectomy may cause cataract formation, retinal detachment, infection, glaucoma, bleeding or a re-opening of the macular hole. 

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

If you would like to schedule an appointment, please call us (877) 245.2020.

Gas Bubbles and Retina Surgery

Not all retina surgery requires a gas bubble, but here’s when it is necessary for your retina specialist to use a gas.

Not all retina surgery requires injection of a gas bubble.

To safely work on the retina, your retina specialist must be able to safely access the inner layer of the eye. A vitrectomy, the procedure to remove the vitreous, allows the retina specialist specialist to work on the retina. 

A vitrectomy (removal of the vitreous humor gel) is done for the following conditions:

The Gas Bubble

A tamponade in medical terms is something used to close or block a wound or body cavity to stop bleeding or fluid leakage.

Not all retina surgery requires gas to be injected into the eye. The most common use of gas is for repair of a retinal detachment or macular hole. In the case of the retinal detachment (specifically a rhegmatogenous retinal detachment which is caused by a retinal tear or retinal hole), the gas is used to block (tamponade) the migration of fluid to through the tear to underneath the retina.

In the case of a macular hole, the gas is used to allow the hole to slide closed by surface tension.

The gases commonly used are sulfur hexafluoride (SF6) and perfluoropropane (C3F8), and air. Each of the gases dissipates and is replaced by natural fluid, but the time for complete dissipation varies. Air dissipates and is replaced by natural fluid in 5 to 7 days. Sulfur hexafluoride (SF6) dissipates in 10 to 14 days, and perfluoropropane (C3F8), in 55 to 65 days.

The gas bubble blurs your vision while it is in place. As the bubble dissipates you will see a line across your vision where the gas meets the newly forming fluid which is gradually replacing the bubble. The line will move lower each day and your field of vision will get larger as the natural fluid continues to replace the bubble.

As long as any of the gas bubble remains in your eye you must not fly in an airplane because the bubble can expand in the reduced pressure of the cabin causing severe pain and possible loss of sight.

Head Position

Your surgeon will ask you to position yourself in a specific way during healing and that position is dependent on what part of the retina was repaired.

In cases of macular holes, a face down position is common. Head positioning for retinal detachments depends upon the location of the retinal tear(s).

Gas Bubble Injected Last

Most retina surgery is outpatient surgery and can be done under local anesthetic and mild sedation. The sedation is given by IV and is used for anxiety relief and to put you into a relaxed and sleepy state, known as a “twilight state”. In that state you are conscious and still able to hear and follow simple instructions from your surgeon.

General anesthesia can be used for patients with dementia, severe anxiety, or young children.

Most retina surgeries take less than an hour and some less than 30 minutes. The gas bubble is injected as one of the last steps of the surgery.

Recovery

You will have to wear an eye patch for a day or two following surgery. Recovery time depends on the procedure you had, but is generally two to four weeks. An exception is the repair of a complete retinal detachment which could take several months to heal and for vision to stabilize.

If you would like to schedule an appointment, please call us (877) 245.2020.

Nader Moinfar, M.D., M.P.H.
Retina Specialist
Orlando, FL

Jon Doe