What to do for severe unilateral eye pain with lacrimation and vision changes?

Acute Angle-Closure Glaucoma Until Proven Otherwise

This presentation of severe unilateral throbbing eye pain with lacrimation and cloudy vision is acute angle-closure glaucoma (AACG) until proven otherwise and requires immediate emergency department referral—do not delay for outpatient evaluation or institute other treatments. 1

Immediate Recognition and Action

• AACG is an ophthalmologic emergency that can cause irreversible blindness if untreated, with an 18% risk of permanent vision loss. 2
• The classic triad consists of severe eye pain (often described as throbbing), cloudy/blurred vision, and associated symptoms including lacrimation, conjunctival injection, and often nausea/vomiting. 1
• Send the patient to the emergency department immediately—do not attempt outpatient management or delay transfer to obtain further evaluation. 1

Key Distinguishing Features to Assess Urgently

Critical Red Flags Present in This Case:

• Severe unilateral pain (not mild discomfort) 2
• Vision changes (cloudy vision indicates corneal edema from elevated intraocular pressure) 1
• Lacrimation with pain (suggests acute process, not chronic dry eye) 1

What You Can Quickly Check Before Transfer:

• Pupil examination: Look for a mid-dilated, poorly reactive pupil on the affected side 1
• Corneal clarity: Cloudy cornea suggests elevated IOP with corneal edema 1
• Conjunctival injection: Typically present, often with ciliary flush 1
• Intraocular pressure: If tonometry available, IOP typically >40 mmHg (but do not delay transfer to obtain this) 1

Why This Cannot Wait

• Narrow time window for treatment: Permanent trabecular damage and peripheral anterior synechiae (PAS) formation occur during iridocorneal apposition, making the condition irreversible if not treated promptly. 1
• The longer the IOP remains elevated, the greater the likelihood of optic nerve damage and permanent visual field loss. 1
• Even after successful treatment, 8% of patients have inadequately controlled IOP, with 30% of these occurring in the first month. 1

Emergency Department Management (For Your Awareness)

The ED will initiate medical therapy to rapidly lower IOP before definitive laser iridotomy: 1

• Topical beta-blockers (e.g., timolol) to suppress aqueous production 1
• Topical alpha-2 agonists (e.g., brimonidine) 1, 3
• Topical or systemic carbonic anhydrase inhibitors to reduce aqueous formation 1
• Topical miotics (pilocarpine) once IOP begins to decrease—ineffective when IOP markedly elevated due to pressure-induced sphincter ischemia 1
• Systemic hyperosmotic agents (mannitol or oral glycerol) for rapid IOP reduction 1

Definitive treatment is laser peripheral iridotomy (LPI), performed as soon as the cornea clears enough to visualize the iris, which relieves pupillary block and prevents PAS formation. 1

Critical Differential Diagnoses to Consider

While AACG is the primary concern, briefly consider:

Less Likely But Possible:

• Anterior uveitis: Usually presents with photophobia, smaller pupil, and less dramatic IOP elevation 4
• Scleritis: Deep boring pain, worse at night, but typically without cloudy vision 4
• Corneal pathology (ulcer, keratitis): Would show epithelial defect on fluorescein staining 4

Can Be Ruled Out by History:

• Conjunctivitis: Presents with discharge (purulent or watery), no vision changes, and mild discomfort rather than severe throbbing pain 5
• Neuropathic ocular pain: Chronic burning/stinging pain with symptoms outweighing signs, not acute severe throbbing with cloudy vision 1, 2

Common Pitfalls to Avoid

• Do not assume this is "just conjunctivitis" because of lacrimation and redness—conjunctivitis does not cause severe pain or cloudy vision. 5
• Do not start topical corticosteroids before ophthalmologic examination, as this can worsen certain conditions and mask accurate diagnosis. 2
• Do not delay transfer to perform extensive workup—AACG diagnosis is clinical and time-sensitive. 1
• Do not give miotics first when IOP is markedly elevated—they are ineffective due to sphincter ischemia and should only be given after IOP begins to decrease. 1

Follow-Up After Emergency Treatment

• The fellow eye requires prophylactic laser iridotomy, as it has similar anatomic predisposition (narrow angles). 1
• Even after successful iridotomy, some patients develop persistent IOP elevation requiring chronic medical therapy similar to open-angle glaucoma management. 1
• Cataract extraction may be considered as definitive treatment in some cases, as it can substantially lower IOP in angle-closure patients. 1