What is the management for pain on dilatation of the eye?

Management of Pain on Eye Dilation

Pain during pupillary dilation is most concerning for intermittent angle closure, which requires urgent ophthalmologic evaluation with gonioscopy and prophylactic laser peripheral iridotomy to prevent progression to acute angle-closure crisis and permanent vision loss. 1, 2

Immediate Clinical Assessment

When a patient reports pain with pupillary dilation, the ophthalmologist must urgently evaluate for primary angle-closure disease spectrum:

• Perform gonioscopy in a dark room using a four-mirror lens with a bright, short beam that does not pass through the pupil to avoid inducing pupillary constriction 1
• Measure intraocular pressure using Goldmann applanation tonometry before and after any dilation 3
• Assess for anatomically narrow angles, which place patients at high risk for acute angle-closure crisis 1
• Look for risk factors including Asian descent, hyperopia, older age, female gender, and short axial length 2

Critical pitfall: Standard examination between symptomatic episodes may appear completely normal, making dark-room dynamic gonioscopy essential for diagnosis 2

Risk Stratification for Dilation

High-Risk Patients (Narrow Angles)

For patients with suspected occludable angles, dilation should be done with extreme caution as it can precipitate acute angle closure 1, 4:

• Tropicamide is safer than cyclopentolate for necessary dilations in at-risk eyes 5
• Phenylephrine alone is the safest mydriatic option in high-risk eyes, avoiding parasympatholytic agents entirely 5
• Pretreatment with oral acetazolamide reduces but does not eliminate the risk of acute angle closure (0.64% still developed AAC despite prophylaxis) 3
• Narrower gonioscopic angle width and higher baseline IOP are significant risk factors for IOP elevation after dilation 3

If Dilation is Essential Despite Risk

When dilation is deemed necessary (e.g., for suspected retinal pathology) in patients with narrow angles 1:

• Warn patients about signs and symptoms of acute angle closure until iridotomy has been performed 1
• Monitor IOP 1 hour post-dilation 3
• Have immediate treatment available if acute angle closure is precipitated during the clinic visit 1

Definitive Management

For Confirmed Intermittent Angle Closure

Laser peripheral iridotomy (LPI) is the definitive treatment to relieve pupillary block and prevent acute attacks 1, 2:

• Perform LPI as soon as possible after diagnosis 1
• Prophylactic LPI in the fellow eye is mandatory, as approximately 50% of fellow eyes develop acute angle closure within 5 years 1
• LPI should be performed in the fellow eye within days of presentation, not delayed 1

Acute Management if Angle Closure Occurs

If acute angle-closure crisis is precipitated by dilation 1, 6:

1. Immediately administer topical medications:

   • Beta-adrenergic antagonists 1, 6
   • Alpha2-adrenergic agonists 1, 6
   • Topical carbonic anhydrase inhibitors 1, 6

2. Add systemic agents for rapid IOP reduction:

   • Oral or intravenous carbonic anhydrase inhibitors 1
   • Oral or intravenous hyperosmotic agents (mannitol or hypertonic saline) 1, 6

3. Consider parasympathomimetics (pilocarpine) to constrict the pupil and open the angle, though this may be ineffective when IOP is markedly elevated due to pressure-induced ischemia of the pupillary sphincter 1, 7

4. Perform laser iridotomy as soon as corneal clarity permits 1, 6

5. If cornea remains edematous, clear it with topical hyperosmotic agents, anterior chamber paracentesis, or peripheral laser iridoplasty 1

Alternative Diagnoses to Consider

Plateau Iris Syndrome

If pain on dilation persists after LPI has been performed 1:

• This indicates plateau iris syndrome (recurrent high IOP when pupil dilates despite patent iridotomy) 1
• Treatment options include peripheral laser iridoplasty, chronic miotic therapy, or other surgical procedures 1
• Note: Prophylactic iridoplasty can be painful for the patient and may cause inflammation, so the decision to treat versus observe is discretionary 1

Neuropathic Ocular Pain

Consider this diagnosis when symptoms significantly outweigh clinical signs 2:

• Characteristic pain descriptors include burning, stinging, or aching with photophobia and wind sensitivity 2
• Diagnostic anesthetic challenge test differentiates peripheral (improves with anesthetic) from central causes (persistent pain) 2
• Treatment differs completely from angle-closure disease, including autologous serum tears and oral neuromodulators 2

Critical Contraindications

Chronic miotic therapy is NOT an appropriate alternative to iridotomy for either prophylaxis or treatment 1:

• Approximately 40% of fellow eyes treated with miotics alone still develop acute angle closure within 5 years 1
• Miotic use can promote progressive synechial angle closure 1

Post-Iridotomy Management

Once LPI has been performed, dilated fundus examination can be safely performed for complete optic nerve documentation 1:

• Follow patients at appropriate intervals with repeat gonioscopy to monitor for increasing peripheral anterior synechiae 1
• Monitor for secondary angle closure from cataract progression and increased lens thickness 1
• Consider cataract extraction as a treatment option, as growing evidence shows substantial IOP lowering in some PAC and PACG patients 1