A 62-year-old hypermetropic woman survived a classic acute angle-closure attack in her right eye last night — pain, vomiting, haloes, pressure in the high fifties — broken with medical treatment overnight. Her left eye has never had symptoms, but gonioscopy shows an occludable narrow angle. She is reluctant: ‘Why laser a healthy eye?’
Examination Findings
A 62-year-old hypermetropic woman presented last night with a classic acute angle-closure attack in the right eye: severe pain, vomiting, haloes, visual acuity 6/60, corneal oedema, mid-dilated non-reactive pupil, shallow anterior chamber, pressure 58 mmHg. She was treated medically overnight and the attack has broken; pressure is now normalising. The LEFT eye — never symptomatic — shows a very shallow anterior chamber and gonioscopy reveals an occludable narrow angle (iridotrabecular contact in most quadrants). The left disc and fields are currently normal. She asks why the ‘good eye’ needs a laser procedure when it has never hurt.
Investigations
Gonioscopy of both eyes (the attacked eye once the cornea clears, the fellow eye now). Anterior chamber depth assessment. Disc and field baseline for both eyes. The attacked eye needs ongoing assessment for optic nerve damage from the acute pressure spike and for lens/iris sequelae (glaucoma secondary to the attack, cataract).
Questions to Think About
- Why is the asymptomatic fellow eye in danger?
- What exactly does the laser hole do?
- What ongoing risks does the attacked eye still carry after the attack is broken?
Diagnosis
Acute primary angle closure (right eye, treated) — the fellow eye has an occludable narrow angle and needs prophylactic laser peripheral iridotomy.
Reasoning
Reasoning: the acute attack was primary pupillary block — aqueous trapped behind a bowed iris in a predisposed hypermetropic eye. Medical treatment broke this attack, but the anatomy is bilateral: the fellow eye’s occludable angle on gonioscopy means it carries the same time bomb. Laser peripheral iridotomy creates a bypass for aqueous, equalising pressure in front of and behind the iris so the iris falls flat and the angle opens — it prevents pupillary-block attacks. The attacked eye still needs its own iridotomy plus assessment for the attack’s aftermath: peripheral anterior synechiae, pressure elevation, and optic nerve damage from the spike. Diagnosis: resolved acute primary angle closure (right) with an occludable fellow eye. Management: typical management is prophylactic laser peripheral iridotomy for the fellow eye without delay, iridotomy and sequelae assessment for the attacked eye, and lifelong angle-closure follow-up for both — because the second eye’s attack is preventable, and prevention is the whole point.
Differential Diagnosis
- Secondary angle closure (neovascular/uveitic) — ruled out: no rubeosis, no inflammation; the mechanism is primary pupillary block.
- Acute anterior uveitis — ruled out: the mid-dilated non-reactive pupil, corneal oedema, and very high pressure define angle closure, not uveitis.
- Migraine — ruled out: the ocular signs (pressure, pupil, shallow chamber) localise it to the eye.
- Phacomorphic crisis — ruled out: the lens is not intumescent; this is primary pupillary block in a hypermetrope.
Management
Urgent laser peripheral iridotomy for the fellow (left) eye — prophylactic, before any attack. For the attacked right eye: laser iridotomy once the cornea clears and inflammation settles, plus assessment for ongoing angle damage (gonioscopy for synechiae), optic nerve damage from the spike, and later cataract. Long-term: both eyes monitored as angle-closure eyes; lens extraction is considered if the lens contributes to crowding. Family screening advice for narrow angles.
Key Learning Points
- An acute angle-closure attack in one eye means the fellow eye is at high risk — the anatomy is usually bilateral; prophylactic laser peripheral iridotomy of the fellow eye is standard.
- Laser peripheral iridotomy cures pupillary block by giving aqueous a bypass hole — it does not cure all angle closure (plateau iris and lens mechanisms need separate consideration).
- The attacked eye needs more than attack-breaking: assess for residual angle damage, synechiae, and optic nerve injury from the pressure spike.
- Hypermetropia, shallow chamber, and increasing age are the risk profile — the family should know narrow angles run in families.
- Medical treatment breaks the attack; laser prevents the next one — the two are complementary, not alternatives.
Red Flags
- Fellow-eye iridotomy delayed or declined — the second attack is a matter of time, not chance.
- Attacked eye discharged without gonioscopy and disc assessment — synechial closure and nerve damage are missed.
- Plateau iris component unrecognised — iridotomy alone will not hold the angle open.
- Family members never screened — narrow angles are familial.
Educational content only — not medical advice. Clinical decisions must be made by a qualified professional for the individual patient.