Macular Holes

Synonyms: Macular cyst, retinal hole, retinal perforation

Prevalence is 3.3 per 1000 >55 years in the USA.¹ Recent studies in India and Denmark have shown prevalences of 0.14-0.17%.^2,3 In the UK incidence is approximately 1 per 10,000 per year.

Women are more commonly affected than men. Peak incidence is in 70-80 years age group.

Usually idiopathic (<10% have a history of trauma). The most widely accepted theory suggests that age-related focal shrinkage of the prefoveal vitreous cortex causes traction on the foveal area, leading to foveal detachment and subsequent macular hole formation.⁴
Other risk factors include cystoid macular oedema, retinal detachment, laser injury, hypertension, very high myopia and diabetic retinopathy.

It may rarely be an incidental finding. Symptoms appear gradually over days/weeks:

• Distorted vision as well as visual loss.
• Visual acuity will depend on the site of the hole i.e. small eccentric holes may have little effect on acuity.
• Holes that are not full thickness also have less effect on acuity.
• Look for a tiny well-defined 'punched out' area of the macula which can be hard to detect. There may be yellow-white deposits at the base with a grey margin around it - oedema.
• Slit lamp examination will show "a round excavation with well-defined borders" interrupting the beam of the slit lamp.
• Most patients also have a semitranslucent tissue over the hole, which may be surrounded by a grey halo caused by detachment of the retina.

Diagnosis is usually made clinically; however the following may be useful:

• Ocular coherence tomography (OCT) provides high-resolution cross-sectional imaging of the retina and is useful in predicting prognosis.⁶
• Fluorescein angiography (FA) although not usually necessary, may be useful in differentiating macular holes from cystoid macular oedema and choroidal neovascularization (CNV).
• It typically shows a window defect early in the angiogram that does not expand with time, and there is no leakage or accumulation of dye.
• There may be Amsler grid abnormalities. However, plotting small central scotomas is often difficult.

Check local protocol (units are usually happy to have a chat on the phone and take things from there).
Ultimately, the patient will need to be seen by a vitreo-retinal surgeon. Not all units have one so, if your local unit is small, it is worth mentioning to the patient that they may well be sent to the nearest bigger unit for further assessment and treatment. This has the dual effect of helping the patient feel that they are going through a normal process of referral, rather than feeling that they are being passed from pillar to post. It also to prepares them for the fact that they have a bit of a long day ahead, important especially for diabetic or elderly patients, and so helps preparations. That's also where surgery will be carried out.

• About 50% of stage 1 holes resolve spontaneously, but almost all stage 2 (and above) progress without surgery.
• The chosen surgery depends on the staging of the hole. Surgical closure of the hole is considered up until stage 3 or 4 associated with a visual acuity of 6/18 or worse. If the macular hole has been present for 1-3 years, then surgery is likely to work. If it has been present for 5 years or longer, then results may be more variable.
• Vitrectomy may relieve traction on the edge of the hole. The vitreous ±internal limiting membrane are removed and a long-acting gas bubble is introduced to tamponade the macula back into position. It has long been believed that this would only be effective if the patient spent the 1-2 post-operative weeks face down. However recent research has shown this assertion to be incorrect.⁷ The procedure has been shown to be safe and effective.⁸
• Vitrectomy (with fluid-gas exchange for stage 2, 3, and 4 holes) improves vision compared with conservative treatment. Series of patients have been variously reported with hole closure rates of 73-95%. Most patients' visual acuity improves by 2 lines of the Snellen chart.^9,10,11
• Success is also possible if the hole is longstanding (6 months-2 years) or if the patient is aged >80.^12,13
• Occasionally more than one operation is required to close the hole.
• Recently, standard vitrectomy with internal limiting membrane (ILM) maculorrhexis (peeling) has been performed in patients with stage 3 or 4 idiopathic macular holes. The retina is massaged to approximate the edges of the hole as closely as possible. This technique gives a good anatomical and functional result.¹⁴
• For those patients who have a condition that precludes surgery, visual rehabilitation may be the only option with e.g. referral to low visual aids clinic if need be. These patients will not have ongoing ophthalmology review but are followed in the community by an optician.
• Zinc and β-carotene replacement have been advocated (Ocuvite®). These are unproven and contraindicated with actively bleeding ulcers.

Many patients develop cataracts. 76% of cases require extraction within 2 years of macular surgery.
Other problems include:

• Retinal detachment
• Latrogenic retinal tears
• Macular retinal pigment epithelium changes
• Enlargement of the hole
• Macular light toxicity
• Post-operative intraocular pressure spikes
• Endophthalmitis

• Stage 1 holes spontaneously resolve in 50% of cases.
• Stage 2 holes almost always progress without surgery. With surgery, early stage 2 holes show anatomical closure in >90% of cases and a 2 or more line improvement on the Snellen chart in 80% of cases. NB: repair and visual acuity (VA) not necessarily correlated.
• 10% stay the same and 10% lose some VA.

There is a 12% chance (may increase to 20% if other risk factors are present) of a similar hole developing in the other eye.