What are the treatment options for sudden onset of pain and redness in one eye with hypertension (high blood pressure)?

Acute Angle-Closure Glaucoma Until Proven Otherwise—Immediate Ophthalmology Referral Required

This presentation of sudden pain and redness in one eye with high blood pressure is an ophthalmic emergency until proven otherwise, requiring immediate measurement of intraocular pressure (IOP) and urgent ophthalmology consultation within 1-2 hours. 1, 2

Critical Differential Diagnosis

The two most urgent conditions to rule out are:

1. Acute Angle-Closure Glaucoma (AACG)

• Classic presentation: Abrupt onset of unilateral painful red eye with blurred vision, often accompanied by nausea, vomiting, and headache 2, 3
• Physical findings: Mid-dilated, non-reactive pupil; corneal edema (cloudy cornea); shallow anterior chamber; markedly elevated IOP (typically >40 mmHg) 1, 2
• High blood pressure may be reactive to severe ocular pain rather than causative 3
• This is a true emergency: Permanent vision loss occurs within hours if untreated 1, 2

2. Malignant Hypertension with Advanced Retinopathy

• Requires BP typically >200/120 mmHg with bilateral flame-shaped hemorrhages, cotton wool spots, or papilledema 1, 4
• Key distinguishing feature: Advanced hypertensive retinopathy is almost always bilateral, though one eye may be more symptomatic initially 4, 5
• Associated findings: Acute renal failure, thrombotic microangiopathy, or hypertensive encephalopathy 1

Immediate Assessment Required

Measure these parameters immediately:

• Visual acuity in each eye separately 3, 6
• Intraocular pressure using tonometry—this is the single most important test to rule out AACG 1, 2, 3
• Pupil reactivity and size (mid-dilated fixed pupil suggests AACG) 2, 3
• Fundoscopic examination to assess for bilateral retinal hemorrhages, cotton wool spots, or papilledema 1, 4, 5
• Blood pressure in both arms to confirm hypertensive emergency 1

Red flags demanding immediate ophthalmology referral:

• Severe eye pain not relieved by topical anesthetics 6, 7
• Decreased vision 6, 7
• Significant photophobia 7
• IOP >21 mmHg (normal is 10-21 mmHg) 1, 2
• Mid-dilated, poorly reactive pupil 2, 3
• Corneal cloudiness or edema 2, 3

Management Algorithm

If Acute Angle-Closure Glaucoma is Suspected:

Immediate medical treatment (while arranging urgent ophthalmology consultation):

1. Lower IOP pharmacologically before definitive laser treatment 1

   • Topical ocular hypotensive agents perioperatively 1
   • Acetazolamide 500 mg IV initially, then 250 mg every 4 hours (or 250-375 mg PO if IV unavailable) 8
   • Low-strength topical miotics to facilitate subsequent laser iridotomy 1

2. Definitive treatment is laser peripheral iridotomy (LPI) performed by ophthalmologist 1

   • This relieves pupillary block and is curative 1
   • IOP must be checked within 30 minutes to 2 hours following laser surgery 1
   • Topical corticosteroids prescribed postoperatively 1

3. Post-procedure monitoring: Confirm iridotomy patency by visualizing anterior lens capsule; measure IOP; perform gonioscopy to assess for peripheral anterior synechiae 1

If Hypertensive Emergency with Advanced Retinopathy:

Only if bilateral retinal findings are present (flame hemorrhages, cotton wool spots, papilledema):

1. Admit for IV antihypertensive therapy 1
2. Reduce mean arterial pressure by 20-25% over several hours (not immediately, to avoid ischemic complications) 1, 4, 5
3. First-line IV agents: Labetalol, nicardipine, or clevidipine 4
4. Avoid excessive rapid BP lowering which can cause organ hypoperfusion 1, 5
5. Laboratory workup: Hemoglobin, platelets, creatinine, lactate dehydrogenase (to assess for thrombotic microangiopathy) 1

If Neither Emergency is Confirmed:

Less urgent causes of unilateral red eye with pain:

• Anterior uveitis (iritis): Requires ophthalmology referral but not emergent 3, 6
• Infectious keratitis: Requires ophthalmology consultation 3, 6
• Scleritis: Requires ophthalmology consultation 3, 6
• Corneal abrasion: Can be managed in primary care with fluorescein staining 3, 6

Critical Pitfalls to Avoid

• Never assume high BP is the primary cause without measuring IOP—AACG can cause reactive hypertension 2, 3
• Do not delay ophthalmology referral for suspected AACG to "get BP under control first"—permanent vision loss occurs within hours 1, 2
• Do not use mydriatic agents (pupil dilators) if AACG is suspected, as this worsens angle closure 1
• Unilateral presentation strongly favors AACG over hypertensive retinopathy, which is characteristically bilateral 4, 5
• Do not prescribe topical steroids without ophthalmology consultation, as they can worsen infectious keratitis 6
• If diagnosis is uncertain, refer to ophthalmology immediately—delayed diagnosis of AACG results in irreversible blindness 9, 6