Nitrogen bisphosphonate-induced orbital inflammatory disease: gamma delta T cells--a report and review of 2 cases.

With the increased use of nitrogen bisphosphonate therapy for osteoporosis, multiple myeloma, metastatic prostate carcinoma, and Paget disease, it is now recognized that orbital inflammation is a potential sequelae of treatment. To date, 15 isolated cases of orbital inflammation exist in the literature with additional 2 cases reported herein. While the precise triggering mechanism for orbital inflammation is not definitively understood, it appears that a regulatory response from gamma delta T cells is the most likely causative factor. Nitrogen bisphosphonates are a causative agent of orbital inflammatory disease. These case reports adhered to the principles of Helsinki and the Health Insurance Portability and Accountability Act.