A controlled trial of regional sympatholysis in the treatment of photo-oculodynia syndrome.

INTRODUCTION: The mechanism(s) underlying the eye pain syndrome characterized by photo-oculodynia and decreased tears (herein referred to as PODS) is unknown. Postulating a sympathetically maintained pain mechanism, cervical sympathetic ganglion blocks (CSB) were performed in an open-label trial in two patients as a pilot test of our hypothesis. Because these patients experienced clinically dramatic reductions in signs and symptoms, a double-masked controlled trial was initiated.

METHODS: With Institutional Review Board approval and written informed consent, four other subjects with PODS who had experienced temporary reduction (> 50%) of symptoms with a single lidocaine CSB were enrolled. A randomized, double-masked series of three CSBs (saline, bupivacaine, lidocaine) was scheduled for each subject 2-7 days apart.

RESULTS: CSB with lidocaine and bupivicaine, but not saline, reduced spontaneous pain and light sensitivity and increased production of tears. Symptom reduction lasted for hours to days, extending beyond clinical signs of local anesthetic-induced sympatholysis. It was also observed that sympatholysis extinguished associated blepharospasm in those subjects with this dystonic condition (one subject in the open-label pilot trial and two of three in the controlled trial).

CONCLUSIONS: Results of these preliminary data suggest that the sympathetic nervous system is involved in mediating symptoms associated with PODS in certain individuals.