Is there strong evidence that polarized sunglasses are more effective than non-polarized sunglasses for managing photophobia and post-concussive headache in post-concussion syndrome (PCS)?

Management of Photophobia and Postconcussive Headache with Sunglasses

There is insufficient evidence to recommend polarized over non-polarized sunglasses specifically for managing photophobia and postconcussive headache in post-concussion syndrome. While sunglasses in general may be beneficial for photophobia symptoms, current guidelines do not differentiate between polarized and non-polarized options 1.

Current Evidence on Photophobia Management in PCS

Guideline Recommendations

The 2021 JAMA Network Open guideline on nonpharmacological treatment of persistent postconcussion symptoms acknowledges that visual symptoms, including photophobia, are common after concussion. However, it notes that there were no high-quality intervention studies specifically examining oculomotor vision treatments, resulting in only consensus-based recommendations 1.

The American Academy of Pediatrics clinical report (2010) simply states: "Sunglasses may be considered for athletes with significant photophobia" without specifying lens type 1.

Color-Specific Approaches

Recent research suggests that color-specific approaches may be more beneficial than simply using standard sunglasses:

• In a 2017 study of 51 postconcussion patients, 76% complained of photophobia, and 85% of those with photophobia experienced relief using colored glasses. The colors providing most relief were blue, green, red, and purple 2.

• A 2022 case report described successful management of severe post-concussion photophobia in a soldier using rose-colored special photophobia glasses tinted with FL-41 3.

Pathophysiology of Photophobia in PCS

Understanding the mechanism helps explain treatment approaches:

• Photophobia in post-concussion syndrome likely involves both central and peripheral mechanisms, with neuroinflammation, cortical spreading depolarization, and glutamate excitotoxicity all potentially contributing 4.

• Both image-forming (cone/rod-mediated) and non-image-forming (melanopsin-mediated) visual pathways may be involved in abnormal light processing after concussion 5.

Practical Management Algorithm

1. Assess severity and specific light triggers:

   • Determine if specific light frequencies/colors trigger symptoms more than others
   • Evaluate if indoor lighting or outdoor sunlight causes more distress

2. Initial management options:

   • For outdoor use: Standard sunglasses (polarized or non-polarized) may provide relief
   • For indoor use: Consider colored lenses based on individual response testing

3. Specialized approach if standard measures fail:

   • Test different colored lenses to identify the most effective color for symptom relief
   • Consider FL-41 tinted lenses which have shown benefit in some cases 3

4. Complementary measures:

   • Modify environment (dim lighting, avoid fluorescent lights)
   • Consider hats with brims for additional light protection
   • Address any underlying binocular vision dysfunction that may contribute to symptoms 6

Important Caveats

• Sunglasses should be used as part of a comprehensive management strategy that includes cognitive and physical rest until symptoms resolve 1.

• Overuse of dark sunglasses indoors may potentially lead to dark adaptation and increased photosensitivity over time.

• The specific choice of eyewear should be guided by symptom relief rather than marketing claims about polarization.

• Any persistent photophobia beyond the expected recovery period warrants further evaluation for other potential causes or complications.

While current evidence supports the use of sunglasses for photophobia in post-concussion syndrome, there is insufficient evidence to recommend polarized over non-polarized options. Individual testing of different lens types and colors may be the most effective approach to finding optimal symptom relief.