What causes macular holes?
A macular hole is a defect in the center of the macular area of the retina. The macula gives us sharp central vision and reading vision. The very center portion of the macula, called the fovea, is the thinnest portion of the entire retina. It is in this very delicate foveal area that a macular hole can develop. This is one of the main conditions that we treat at VitreoRetinal Surgery in Minneapolis and Greater Minnesota.
In most cases, a macular hole develops as a result of anatomical changes that occur spontaneously and not from anything that the patient has done. This type of macular hole occurs most commonly in individuals over 50 years of age and is called an idiopathic macular hole. Occasionally, severe blunt trauma can cause a macular hole. A macular hole can also be seen in a very small percentage of people with retinal detachment, or in conditions that cause severe edema (swelling) of the retina.
What are the symptoms of a macular hole?
A macular hole causes loss of sharp “straight-ahead” vision and reading vision. In the early stages of macular hole formation, the hole is very small and the central vision may be only slightly blurred or distorted. As the hole enlarges, the vision becomes progressively worse. The hole typically enlarges to a point at which the affected eye can only see the larger letters of an eye chart. A macular hole does not cause complete blindness and does not affect the peripheral (side) vision.
Is there a procedure to treat macular holes?
A macular hole can be treated with vitrectomy surgery. With current surgical techniques, most macular holes can be repaired with a success rate of about 95%. There is no non-surgical treatment for a macular hole.
Vitrectomy surgery is usually done on an outpatient basis under local anesthesia. The surgery consists of making very small incisions on the white part of the eye (the sclera). After the vitreous gel is removed, the surgeon peels a very thin membrane called the “internal limiting membrane” from the surface of the retina around the macular hole. A gas bubble is then placed in the vitreous cavity. Newer surgical techniques and instrumentation may allow the surgeon to perform the surgery in some cases through tiny “self-sealing” incisions that do not require sutures. Eye drops or ointment are used for several weeks after surgery to facilitate healing. The gas bubble will gradually go away over several weeks following surgery.
What should I know about the post-operation for macular hole surgery?
The most important part of macular hole surgery is the requirement for post-operative face-down positioning. In order for the macular hole to close, the gas bubble must press against the macular hole. Since the macular hole is located directly at the back of the eye, the most effective way to keep the bubble against the hole is for the patient to keep their nose pointed directly downward toward the floor. A variety of positioning aids, such as massage chairs and head-rests, are available to make this requirement more tolerable. The duration of face-down positioning may vary but the average time is 4 to 5 days.
The amount of visual improvement varies depending on whether the macular hole closes, how long the macular hole was present, the anatomic characteristics of the macular hole, and the presence of any other ocular abnormalities that might limit vision. Many patients recover very good vision. However, some individuals may have more limited improvement, and a small percentage of people may not improve very much at all even with successful surgery. It takes anywhere from 3 months to 1 year for vision to reach its maximal improvement.
Any surgical procedure carries a risk of complications, and macular hole surgery is no exception. Post-operative infection (endophthalmitis) can be very serious and may lead to blindness in the affected eye. Most infections can be effectively treated if identified at an early stage. Endophthalmitis is rare and occurs in approximately 1 out of 1000 cases. Retinal detachment is another complication that can cause blindness if not treated. Retinal detachments occur in 1 to 2 out of 100 cases following macular hole repair. The progression of cataract is a third consideration in macular hole surgery. A cataract occurs when the lens in the eye becomes cloudy. This typically occurs with aging but is accelerated by vitrectomy surgery. This is not a concern if the patient has already had cataract surgery prior to vitrectomy surgery. Other risks of surgery include bleeding, loss of vision, double vision, scarring, a droopy eyelid, and anesthetic complications. Your surgeon will review the risks and benefits of surgery with you.