W. Todd Briscoe, OD, FAAO

May 5, 2009

In November 2004, a patient came to me on an emergent basis for bilateral eye pain, blurry vision, burning, photophobia, burning facial skin, and lacrimation.  I tentatively diagnosed a UV photokeratitis based on the signs which included a diffuse SPK as well as bulbar conjunctival staining.  I was troubled by the lack of sunlight or other recognizable UV exposure in the history, as she related to me that she had been indoors at a school in-service meeting all day at the school gymnasium.  I gave the patient lubricants and reassurance that in 48-72 hours all would be well again.  She returned 48 hours later for follow up and had intense sunburn on her exposed face and no resolution in her symptoms.

Through investigation the culprit was found to be a broken Philips Lighting type "R" Metal Halide light bulb.  This bulb had its UV filtering envelope broken by an errant volleyball and had been emitting UV light for an indeterminate time.  My patient received a 5 hour and 20 minute exposure and she was sitting directly under the broken light for a day long in-service.  Theoretically, others could have had less significant injuries; however, typical activities in a gym may have limited longer term UV radiation damage.  Also, the use of UV protecting contact lenses may have mitigated ocular damage.  Four and half years later, this patient is still as symptomatic as when I initially saw her and I now see three other patients with similar injuries.

Photokeratitis is a self limiting condition; unfortunately, the type of injury described above is not.  Given the amount of UV radiation the corneal nerve plexus was damaged (demonstrated with confocal microscopy) and these patients now suffer from trigeminal neuralgia and allodynia.  Their symptoms are severe photophobia and eye pain.  The signs are minimal after initial exposure, but can include conjunctival staining and hyperemia.  Currently, there does not exist a recognized treatment protocol.

Treatments I have utilized included non-preserved lubrication, non-preserved topical steroids, cyclosporine A, topical albumin, bandage soft contact lenses, punctual occlusion, and scleral lenses.  Oral treatments have been directed at controlling the trigeminal neuralgia.  Supportative treatment has included nighttime patching, humidifiers, and moisture chamber sunglasses.  Currently, one patient is undergoing a trial of longer term corneal anesthesia using ropivicaine.

Those injured under intense radiation may not recover and as eye care providers we must focus our treatment at improving their functioning, which can be significantly altered after such an injury.  Further, we must be diligent to avoid the misconception, “no stain - no pain”.  This is a terribly unrecognized entity and many eye care providers dismiss this finding entirely forcing additional psychological burden upon the injured patient.

Thanks to the efforts of these injured patients, Oregon has become the first state to prohibit the use of these types of bulbs in public schools, in favor of Type “T” metal halide bulbs which self extinguish when the protective filter is broken.