Macular Hole

What happens in a macular hole

The macula is a spot about 5 mm across at the center of the retina, packed with cone cells for reading, recognizing faces and seeing color. The very center is called the fovea.

The eye is filled with a clear gel, the vitreous. With age the gel liquefies and shrinks, and eventually separates from the retina, a normal event called posterior vitreous detachment. If the gel stays stuck at the fovea while pulling away elsewhere, the traction can stretch and tear the center open. Fluid then collects at the edges of the hole and the surrounding retina lifts slightly.

Other causes

• Blunt eye injury, such as a ball or fist to the eye
• High nearsightedness (myopia)
• An epiretinal membrane contracting across the macula
• Long-standing swelling of the macula, for example from diabetes or vein occlusion
• Rarely, laser or sun exposure injury

Symptoms of a macular hole

• Blurred central vision in one eye, often noticed when the other eye is covered
• Distortion: straight lines look bent, pinched or wavy (metamorphopsia), for example door frames or lines of text
• A gap or dark spot in the center of vision in later stages
• Difficulty reading and seeing fine detail
• Side (peripheral) vision stays normal

It usually develops over weeks to months and is painless. Because the other eye compensates, many people only notice when they close the good eye. A macular hole does not cause total blindness.

Stages and types

The Gass staging system describes how a hole develops:

Today, ophthalmologists usually describe holes by OCT size (small, medium or large) and whether the vitreous is still pulling, because these predict surgical success.

Related findings:

• Lamellar macular hole: a partial-thickness defect. Vision is often good and many are simply monitored.
• Pseudohole: an epiretinal membrane that makes the center look like a hole without tissue loss.

Macular hole vs macular degeneration

Both cause central blur and distortion, so an exam and OCT scan are needed to tell them apart.

How a macular hole is diagnosed

1. Visual acuity test with an eye chart.
2. Amsler grid: a square grid of lines; holes make the center lines look bent or missing.
3. Dilated eye exam with a slit lamp and lens to view the macula.
4. Optical coherence tomography (OCT): a quick, painless scan that shows a cross-section of the retina, confirms the hole, measures its size and shows any vitreous traction. It is the key test.

Treatment

Watching

Stage 1 holes and lamellar holes are often monitored with repeat OCT scans, because many stay stable or resolve.

Vitrectomy surgery

Full-thickness holes usually need surgery, ideally within a few months of symptoms because older and larger holes close less often. The operation, done under local anesthesia with sedation and usually as day surgery:

1. Removes the vitreous gel through tiny ports in the white of the eye
2. Peels the thin internal limiting membrane around the hole to release traction
3. Fills the eye with a gas bubble that presses the edges of the hole together as it heals

Surgery closes about 90% or more of typical holes. Very large or long-standing holes may need extra techniques, such as a flap of membrane placed over the hole.

Recovery after macular hole surgery

• Head positioning: many surgeons ask patients to keep their face down, or avoid lying on their back, for several days so the bubble floats against the macula. Requirements vary by surgeon and hole size.
• The gas bubble makes vision very blurry. It absorbs over 2 to 8 weeks, and you may see its edge as a wobbling line.
• No flying, mountain travel or nitrous oxide anesthesia until the gas is gone, because the bubble can expand and dangerously raise eye pressure. Many hospitals give you a wristband as a reminder.
• Vision improves gradually over 3 to 6 months or longer. Many people regain good reading vision, though some distortion may remain.
• Eye drops prevent infection and inflammation.

Risks of surgery

• Cataract: most people who still have their natural lens develop a cataract within 1 to 2 years, which is then removed with standard cataract surgery
• Retinal tear or retinal detachment
• Raised eye pressure
• Infection (rare)
• The hole failing to close or reopening, which may need a second operation

Outlook

Without treatment, most full-thickness holes slowly enlarge and central vision worsens, though peripheral vision is kept. After successful surgery, most people have better and less distorted vision than before. The risk of a hole in the other eye is roughly 10 to 15%, lower if that eye's vitreous has already detached.

Frequently asked questions

What are the first symptoms of a macular hole?

Early symptoms are mild blur and distortion in the center of vision in one eye. Straight lines may look bent or pinched, and letters may seem to be missing when reading. Many people notice it only when they cover their other eye.

Can a macular hole heal on its own?

Some can. Early stage 1 holes close by themselves in about half of cases when the vitreous separates fully, and a small number of full-thickness holes also close. Most full-thickness holes enlarge over time without surgery, so they are usually repaired.

How long do you have to stay face down after macular hole surgery?

It depends on your surgeon and the hole size. Some ask for strict face-down positioning for 3 to 7 days, others for a shorter period or only for avoiding lying on your back. Follow your surgeon's instructions, as positioning keeps the gas bubble against the hole while it seals.

Can a macular hole cause blindness?

It does not cause total blindness. It affects only central vision, so side vision remains and people can still walk around safely. Untreated, central vision in that eye can become poor enough to make reading and recognizing faces difficult.

Will a macular hole happen in my other eye?

The risk is about 10 to 15% over time. It is lower if the other eye already has a full posterior vitreous detachment. Check each eye separately with an Amsler grid regularly and see your eye doctor promptly about any new distortion.