Abstract
Purpose:
Many young veteran patients are presenting with chronic aversive light sensitivity (LS), associated with photophobia (PP), and light-induced headache (LHA) despite the absence of any correlated ocular health abnormality or positive neuro-imaging findings, but have a history of potential head trauma. In these patients, LS and LHA are not significantly relieved by headache medications, optical correction or spectral filters. In the course of clinical management attempts we have found, and report here, an unexpectedly long-term relief of symptoms from a single application of pilocarpine, a parasympathetic drug which is a strong stimulus for pupillary and ciliary body constriction.
Methods:
Patients referred to our VA Visual Rehabilitation Clinic for light sensitivity receive a full ocular health workup including optical correction, anterior and posterior segment examinations, and visual fields. They are also administered a multi-part questionnaire that uses 0-10 rating scales for assessing LS & LHA discomfort and interference with daily activities. We have examined the response to a single treatment of pilocarpine (1%, 1-2 drops, O.U.) in 14 patients. Patients were followed for one hour post treatment, by phone the next day, and upon return to the clinic at one week.
Results:
In the immediate post treatment hour, constriction of the pupils was observed in each case, as well as subjective reports of decreased light sensitivity. Also, as expected, a small number of patients developed brow headaches, a known side effect. Within 24 hours pupils returned to normal as self-reported and confirmed by companions. At the one week follow-up, the rating questionnaire was administered again; 70% of subjects reported continuous, substantial relief, with median LS scores dropping from 8.0 to 3.8, LHA scores dropping from 6.5 to 4.0 (Sign Ranked p<.003, n=14). For three subjects relief was gone after the constrictive phase; for one other, relief lasted only a few days post-treatment. The symptoms of the remaining 10 were still reduced by 50% below pre-treatment scores one month later, although symptoms returned in most patients by 6 months.
Conclusions:
Successful treatment with pilocarpine is the first demonstration of a simple, effective drug treatment of PP and LHA. The well established pharmacology is a short term, local effect, suggesting an unknown mechanism triggered by pilocarpine action.
Keywords: 466 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials •
611 neuro-ophthalmology: cortical function/rehabilitation •
667 pupil