What is the best course of action for a patient with visual light sensitivity and blurred vision?

Immediate Ophthalmology Referral for Suspected Ocular Immune-Related Adverse Event or Acute Angle Closure

Any patient presenting with visual light sensitivity (photophobia) and blurred vision requires immediate ophthalmologic evaluation to rule out vision-threatening conditions, particularly if they have risk factors such as immunotherapy exposure, hyperopia, or acute onset symptoms. 1

Initial Assessment by Non-Ophthalmologist

Before referral, perform these bedside evaluations:

• Visual acuity testing using a smartphone eye chart with appropriate corrective lenses 1
• Pupil examination checking for size, shape (mid-dilated or oval suggests acute angle closure), reactivity, and relative afferent pupillary defect 1
• Red reflex assessment 1
• Penlight inspection of the anterior eye for conjunctival hyperemia, corneal edema, or shallow anterior chamber 1
• Color vision testing 1

Critical Red Flags Requiring Emergency Referral

Acute Angle Closure Glaucoma (AACC)

• Mid-dilated, poorly reactive pupil with eye pain, nausea, conjunctival redness, and very high intraocular pressure 1
• Corneal edema (cloudy cornea) with severe photophobia 1
• Risk factors: hyperopia, older age, small corneal diameter 1
• This is an ophthalmologic emergency - untreated AACC causes rapid glaucomatous optic neuropathy and 18% of eyes become blind within 4-10 years 1

Immune-Related Ocular Adverse Events (if on checkpoint inhibitors)

• Uveitis (anterior, posterior, or panuveitis) presents with photophobia, blurred vision, floaters, eye redness, and pain on eye movement 1
• Occurs in <1% of patients on immune checkpoint inhibitors 1
• Do NOT start corticosteroids before ophthalmologic examination unless systemic steroids are indicated for other reasons, as this may obscure the diagnosis 1

Optic Neuritis

• Classic triad: unilateral eye pain (especially with eye movement), subacute vision loss, and impaired color vision in young adults 2
• Requires MRI of orbits and brain with contrast to evaluate for demyelinating lesions 2

Timing of Referral

Same-day ophthalmology consultation is mandatory for:

• Any visual complaints in patients on immune checkpoint inhibitors 1
• Suspected acute angle closure (emergency) 1
• Sudden vision loss with pain 2
• Red, painful eye with photophobia 1

Urgent referral (within days) for:

• Gradual blurred vision with photophobia in older adults 1
• Symptoms not fitting emergency criteria but persistent 1

Common Pitfalls to Avoid

• Do not assume refractive error alone - excellent visual acuity does not exclude serious eye disease 1
• Do not delay referral for slit lamp examination by non-ophthalmologists - detailed evaluation requires ophthalmologic expertise 1
• Do not miss bilateral examination - ocular immune-related adverse events may be asymmetric, so examine each eye separately 1
• Do not overlook systemic symptoms - ocular immune-related adverse events frequently accompany other immune toxicities, especially colitis 1

Additional Considerations

• Hyperopic patients (farsighted, especially older adults) have narrower anterior chamber angles and increased risk of angle closure 1
• History of LASIK or refractive surgery may cause falsely low intraocular pressure measurements 1
• Dim lighting environments (like airplane cabins) can trigger pupillary block and acute angle closure in susceptible individuals 1