Diffuse Unilateral Subacute Neuroretinitis Evolving With Submacular Granuloma.

DUSN is an infectious ocular disease that can lead to severe visual impairment and blindness. It usually occurs in young healthy individuals and depending on the stage of the disease, clinical presentation may range from mild vitritis and multifocal gray-white lesions in outer retina to optic atrophy.Parasites of different sizes and species have been proposed as the etiological agent of this disease. Thus, it is hypothesized that different infectious worms may be considered as the likely cause of a both autoimmune and toxic form of nematode retinopathy.Most patients present with already severe visual impairment and in the later stages of the disease, where the likelihood of improvement is low, despite therapy. In cases of early diagnosis, prompt treatment, whether with oral antihelmintic or direct photocoagulation of the worm, patients may show considerable visual improvement and have a more favorable prognosis.