Macular Holes

Synonyms: Macular cyst, retinal hole, retinal tear, retinal perforation

A macular hole is a full-thickness defect of retinal tissue. It runs from the internal limiting membrane to the outer segment of the photoreceptor layer. It involves the fovea, so affects central visual acuity.

Prevalence is 3.3 per1000 >55 years in the USA.¹ Women are more commonly affected than men. Peak incidence is in 70-80 years age group.
There is a 12% chance of a similar hole developing in the other eye.

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.²

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.
• 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.

Refer for ophthalmological assessment in eye casualty or outpatients. This does not need to be on an urgent basis.

• 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.
• Ocular coherence tomography (OCT); this provides high-resolution cross-sectional imaging of the retina.

• In rare cases the hole may close itself.
• The basic surgical technique is the same in most procedures; the anterior and middle vitreous is removed via a pars plana vitrectomy.
• 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. This may work provided the patient spends the 1-2 post-op weeks face down. A great part of the surgery's success depends on this. The procedure has been shown to be safe and effective.⁴
• 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.^5,6,7
• Success is also possible if the hole is longstanding (6 months - 2 years) or if the patient is aged >80.^8,9
• 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.¹⁰
• Patients not suitable or not wishing for this treatment must rely on visual aids e.g. to read.
• 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
• Iatrogenic retinal tears
• Macular retinal pigment epithelium changes,
• Enlargement of the hole
• Macular light toxicity
• Post-operative intraocular pressure spikes