"Worm in the eye": the rationale for treatment of DUSN in south India.

AIM: To discuss the rationale for different techniques of treatment for DUSN (diffuse unilateral subacute neuroretinitis) and their effectiveness in two patients from south India.

METHODS: Two rare cases of live worms in DUSN from India are reported, where filarial Brugia malayi is endemic. Both cases presented with progressive unilateral loss of vision with no history of animal contact. They were 40 year old, apparently healthy men. In case 1, the worm (1500-2000 microm) was easy to identify with wriggling movements among crisscrossing diffuse subretinal tracks. The worm was destroyed by a single shot of laser to its advancing end, which was followed by oral steroid to control the inflammation caused by the dead worm. In case 2, the worm was small and difficult to identify. Initially diffuse neuroretinitis was diagnosed and treated with intravenous methylprednisolone and oral corticosteroid. A week later, a small live worm (400-600 microm) was found and subsequently destroyed by laser photocoagulation followed by a combination of anthelminthics.

RESULTS: The patients' vision had improved to 6/60-6/36 from counting fingers after a few weeks.

CONCLUSION: The role of a combination of laser treatment, systemic steroid, and anthelminthics is discussed.