This is the second part of my summary of the article Shedding Light on Photophobia. It concerns the article’s last section on diagnosis and photophobia treatment. (You may read about photophobia definition, symptoms and causes here).
Photophobia treatment depends on the cause, however, many photophobia causes tend to be difficult to diagnose. The authors propose a visualization of the diagnostic process along with corresponding photophobia treatments in a flow chart (see below).
Diagnosing the cause
It is important to carefully study patient’s medical history, along with neurologic and neuro-ophthalmic examination including visual fields. Intracranial processes, such as pituitary tumor or meningitis may be present with photophobia. MRI of the brain is recommended when there are focal neurologic findings. Other central causes such as PSP should be considered.
Dry eyes, corneal neuropathy and migraine are the most common photophobia causes. Diagnosing dry eye can be difficult (examination of the tear film, tear film break-up time, corneal staining with Rose-Bengal or fluorescein, and Schirmer’s testing). Another condition difficult to diagnose is corneal neuropathy (instill lidocaine eye drops – if the pain and discomfort resolve, this diagnosis is possible; corneal nerve imaging by confocal microscopy may be helpful).
Migraine is a less problematic to diagnose (look for pain associated with photophobia, phonophobia, nausea and/or vomiting, as well as pain that worsens with activity). Blepharospasm also tends to be less challenging to diagnose (observe frequent blinking). Conversely, reflex blepharospasm in response to bright light can be difficult to identify (observe squeezing of eyes, apraxia of eye lid opening, and involuntary eye closure even to moderate levels of light).
Among the photophobia causes it is also important to screen for depression and anxiety.
Photophobia treatment is one of the most frustrating neuro-ophthalmic problems for clinicians. The authors question the existence of truly known photophobia treatments. Available recommendations for photophobia treatment are based either on studies with small numbers of subjects or case-reports. A major randomized controlled trial of photophobia treatment remains a pending task for photophobia researchers.
Tinted lenses and sunglasses remain a principal photophobia treatment, however they are not always effective. They have been condemned as a symptomatic remedy for photophobia because of their ineffectiveness and their habit forming tendency. Excessive wear of tinted glasses leads to dark adaptation, chronic darkness, which eventually increases the perception and pain of light sensitivity. Note that yellow, orange, red and rose-colored tints (e.g. FL-41 tint) tend to block blue wavelengths, which are more likely to cause photophobia.
Different tints appear work well for different people. Moreover one tint my work well as photophobia treatment given one cause but may exacerbate photophobia in the case of another cause. Sunglasses are reasonable to use in the bright sunlight for patients with migraine, tension type headaches and photophobia.
Dry eyes may be treated with drops. Ointments and possible punctual plugs may be an effective photophobia treatment, particularly when associated with blepharospasm.
- Sedatives (for example barbiturates) are helpful – allow for prolonged sleep and closed eyes.
- Migrane preventive medications (beta blockers, calcium channel blockers, anti-convulsants) are reasonable photophobia treatments. Some migraine specific medications have been shown to reduce photophobia associated with acute migrane attacks. Migraine preventives may also be considered when photophobia is due to dysfunctional excitation/inhibition balance, especially of the antiepileptic class.
- Gabapentin and melatonin have been anecdotally reported to reduce the pain associated with photophobia.
- Antidepressants alleviate photophobia when associated with comorbid depression
- Anxiolytics may be beneficial photophobia treatments in presence of anxiety and panic disorders.
- Botulinum toxin, tricyclic antidepressants, baclofen, benzodiazepam, orphenadrine, carbidopa/levadopa, and fluoxetine have been applied as blepharospasm and the associated photophobia treatment.
- Topical lacosamide or systemic anticonvulsants such as gabapentin, pregabalin, or carbamazepine have been suggested to as corneal neuropathy related photophobia treatment.
Various procedures have also been reported as photophobia treatments in difficult clinical settings:
- injections to the supraorbital nerve has reduced light sensitivity,
- alcohol injected into the orbit in cases of ocular inflammation,
- trigger point injections have relieved whiplash induced cervicalgia and photophobia,
- botulinum toxin injection has reduced photophobia associated with post-traumatic headache,
- superior cervical blockade by lidocaine improved light sensitivity in some patients with photophobia.
The article Shedding Light on Photophobia also contains a long list of references.
Ps: If you found the post What is photophobia: definition, symptoms, and treatment useful, please consider LIKING, REBLOGGING, and/or SHARING it below.