Ophthalmology: Macular Hole

BASICS

Description

A macular hole is a partial-thickness or full-thickness defect involving the retina at the center of the macula, particularly the fovea. Because the fovea is responsible for high-resolution central vision, macular holes can cause significant central visual disturbance.

EPIDEMIOLOGY

Incidence

The estimated annual incidence of macular hole is approximately 7.8–8.7 cases per 100,000 persons.

The highest incidence occurs during the seventh decade of life.

Prevalence

Reported prevalence ranges from approximately 0.02% to 0.8%.

Macular holes occur more frequently in women than in men and most commonly affect individuals older than 55 years of age.

RISK FACTORS

A history of recent ocular trauma is an important risk factor, particularly in younger patients or when the macular hole develops following blunt injury.

PATHOPHYSIOLOGY

The development of a macular hole is strongly associated with abnormal vitreoretinal traction at the fovea.

Persistent attachment of the posterior vitreous cortex to the central macula can exert tractional forces on the foveal tissue. Progressive traction may initially distort the normal foveal contour and eventually produce a partial- or full-thickness retinal defect.

ETIOLOGY

Most macular holes develop idiopathically, particularly in older adults.

Traumatic macular holes can also occur, usually following blunt ocular injury.

DIAGNOSIS

History

Patients commonly report blurred or reduced central vision, distortion of straight lines or objects (metamorphopsia), or a central area of missing vision (central scotoma) in one eye.

Symptoms may develop acutely or subacutely. Because the fellow eye may maintain good visual function, some patients do not recognize the visual deficit until the unaffected eye is accidentally covered.

A history of recent ocular trauma should be specifically sought, particularly when the presentation is atypical or occurs in a younger patient.

Physical Examination

Visual acuity varies according to the size and stage of the macular hole and may range from approximately 20/25 to 20/400.

Patients with a well-established full-thickness macular hole often have visual acuity around 20/200, although considerable variation occurs.

The diagnosis is primarily established by careful biomicroscopic examination of the macula, usually with a handheld indirect lens or a fundus contact lens.

Typical examination findings include:

• A dark, round or oval defect located at the center of the fovea
• A small surrounding neurosensory retinal detachment, which may appear as a fluid-filled cuff
• Small yellow-white deposits or dots at the level of the retinal pigment epithelium
• A possible pseudo-operculum suspended above the macular hole

Gass Biomicroscopic Classification

Macular holes may be classified according to the traditional Gass staging system.

Stage 1: Impending Macular Hole

The foveal depression is lost and a central yellow abnormality develops.

Stage 1A is characterized by a central yellow spot.

Stage 1B is characterized by formation of a yellow ring.

At this stage, a complete full-thickness retinal defect has not yet formed.

Stage 2

A small full-thickness macular hole, traditionally measuring less than approximately 400 microns, becomes visible within the fovea.

Stage 3

A larger full-thickness macular hole, traditionally greater than approximately 400 microns, is present without a complete posterior vitreous detachment.

Stage 4

A full-thickness macular hole is present in association with a posterior vitreous detachment.

Watzke-Allen Test

The Watzke-Allen test may be used clinically to help distinguish a full-thickness macular hole from a lamellar hole, pseudohole, or other macular abnormality.

During the test, a narrow slit-lamp beam is projected across the center of the macular lesion using a macular contact lens.

A patient with a full-thickness macular hole may describe the light beam as having a central break, interruption, narrowing, or compression.

DIAGNOSTIC TESTS AND INTERPRETATION

Laboratory Testing

Routine laboratory investigations are not indicated in the evaluation of an uncomplicated macular hole.

Imaging

Optical Coherence Tomography

Optical coherence tomography (OCT) is the principal imaging technique used to confirm the diagnosis and characterize the macular hole.

OCT provides high-resolution cross-sectional images of the retina and can demonstrate:

• A partial- or full-thickness defect involving the fovea
• The size and configuration of the macular hole
• Vitreomacular adhesion or vitreomacular traction
• Intraretinal cystic changes around the hole
• Elevation of the retinal edges
• A pseudo-operculum when present
• The relationship between the posterior vitreous and the macula

OCT is also valuable for surgical planning and for documenting anatomical closure following treatment.

Diagnostic Procedures

Laser Aiming Beam Test

A small laser aiming beam, traditionally approximately 50 microns in diameter, may be directed toward the center of the suspected lesion.

A patient with a full-thickness macular hole may be unable to perceive the light spot when it is positioned directly over the hole. Patients with other macular abnormalities may still be able to see the aiming beam.

This test is used much less frequently now because OCT provides more detailed and objective anatomical information.

Pathological Findings

Histopathologic examination is generally unnecessary because tissue specimens are not routinely obtained during the diagnosis or surgical treatment of a macular hole.

DIFFERENTIAL DIAGNOSIS

Conditions that may resemble a macular hole include:

• Epiretinal membrane with a macular pseudohole
• Lamellar macular hole
• Vitreomacular traction
• Cystoid macular edema
• Macular cyst
• Pigment epithelial detachment
• Central serous chorioretinopathy

Careful fundus examination and OCT imaging are particularly useful for differentiating these conditions from a true full-thickness macular hole.

TREATMENT

Medication

There is no conventional medication that directly closes an established full-thickness macular hole.

Management is therefore primarily based on observation in selected cases or vitreoretinal intervention when treatment is indicated.

ADDITIONAL TREATMENT

Issues for Referral

Patients with a suspected or confirmed full-thickness macular hole should be referred to a vitreoretinal specialist for assessment and discussion of management options.

Complementary and Alternative Therapies

No complementary or alternative therapy has an established role in the treatment of macular holes.

SURGERY AND OTHER PROCEDURES

Surgical repair is the standard treatment for most visually significant full-thickness macular holes.

The usual procedure is pars plana vitrectomy with intraocular gas tamponade.

During surgery, the vitreous is removed and traction on the macula is released. In many cases, the surgeon also performs internal limiting membrane (ILM) peeling around the fovea to improve the likelihood of anatomical hole closure.

A gas bubble is then placed inside the eye to provide temporary internal tamponade and facilitate approximation of the edges of the macular hole.

Surgery is generally not considered an immediate emergency. However, once intervention has been recommended, repair is commonly undertaken within a relatively short period because longer-standing holes may have a less favorable visual prognosis.

Postoperative positioning instructions depend on the characteristics of the hole, the gas used, and the surgeon’s technique. Some patients may be instructed to maintain a face-down position for a period after surgery.

Patients with their natural crystalline lens remain at increased risk of developing or accelerating cataract formation after vitrectomy and may subsequently require cataract extraction.

INPATIENT CONSIDERATIONS

Initial Stabilization

Macular hole treatment is generally managed on an outpatient basis.

Hospital admission is not ordinarily required for uncomplicated cases.

ONGOING CARE

Follow-Up Recommendations

Patients should be evaluated by a vitreoretinal surgeon to determine whether surgical treatment is appropriate.

Following surgery, ophthalmic examinations are commonly performed at intervals such as:

• The first postoperative day
• Approximately 1 week after surgery
• Approximately 2–3 weeks after surgery
• Approximately 6–12 weeks after surgery

The exact follow-up schedule varies according to surgical findings, intraocular pressure, the type of gas tamponade used, retinal status, and postoperative recovery.

OCT may be repeated to confirm anatomical closure of the hole and monitor restoration of the foveal architecture.

PATIENT EDUCATION

Patients should be informed that a macular hole can also develop in the fellow eye. Reported rates of fellow-eye involvement are approximately 5–20%, depending on the vitreomacular anatomy and duration of follow-up.

Patients should therefore monitor the vision in each eye separately and promptly report new central blurring, distortion, or a central blind spot in the opposite eye.

Following vitreoretinal surgery, patients should also be educated about symptoms that may indicate a retinal tear or retinal detachment, including:

• New flashes of light
• A sudden increase in floaters
• A curtain, shadow, or veil across the visual field
• Sudden deterioration in peripheral or central vision

These symptoms require urgent ophthalmologic evaluation.

Patients who receive an intraocular gas bubble must follow the surgeon’s specific postoperative precautions, including restrictions related to altitude and certain forms of anesthesia until the gas has completely resolved.

PROGNOSIS

Modern macular hole surgery has a high anatomical success rate, with hole closure achieved in more than 90% of appropriately selected cases.

Visual recovery varies between patients. Successful anatomical closure usually improves or stabilizes central vision, although the final visual acuity depends on factors such as the size of the hole, duration of symptoms, preoperative retinal changes, and restoration of the outer retinal layers.

Earlier treatment of suitable macular holes is generally associated with a better potential for visual improvement than treatment of longstanding disease.

COMPLICATIONS

Potential complications associated with macular hole and its surgical treatment include:

• Cataract formation or progression, particularly after vitrectomy in phakic patients
• Retinal tears
• Retinal detachment
• Persistent or recurrent macular hole
• Intraocular pressure abnormalities following surgery
• Rare macular hole-associated retinal detachment

Although anatomical closure is achieved in most surgically treated cases, the degree of postoperative visual improvement remains variable.