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Retinal neovascularization and hemorrhage associated with the use of imatinib (Gleevec(®)) in a patient being treated for gastrointestinal stromal tumor (GIST).

BACKGROUND
Gastrointestinal stromal tumor (GIST) is a mesenchymal malignancy of the gastrointestinal tract. Imatinib mesylate (Gleevec(®), ST1571, Novartis Pharmaceuticals, Basel, Switzerland) is a selective inhibitor of break point cluster-Ableson (BCR-ABL), c-Kit, and platelet-derived growth factor receptor alpha (PDGFRα) tyrosine kinases. Imatinib has been approved in the U.S. for the treatment of Philadelphia-chromosome positive chronic myeloid leukemia, KIT (CD117)-positive unresectable and metastatic malignant GIST and adjuvant treatment of adult patients following resection. Ocular side effects are commonly reported with Gleevec(®), the most common being periorbital edema and epiphora.


CASE REPORT
Here we present the case of a 62-year-old male with a history of GIST in the jejunum who was started with imatinib mesylate at 400 milligrams daily. Seven months into his therapy, he reported blurry vision. He was evaluated by an ophthalmologist, and was ultimately found to have retinal hemorrhage and neovascularization. His dose was reduced by 50% to 200 milligrams daily with an almost complete resolution of symptoms within several weeks. No recurrence of symptoms or signs was noticed at 6 months follow-up.


DISCUSSION
This patient's Naranjo scale was calculated to be 7, indicating a probable adverse drug reaction. Our patient's symptoms significantly improved with a dose reduction of imatinib, and this hints that there was a dose-dependent effect. The World Health Organization has categorized retinal hemorrhage as an unlikely side-effect of therapy, and to our knowledge this has never been reported before in a patient receiving imatinib mesylate for GIST treatment. Neovascularization also has not been previously reported in patients receiving this medication. It is important to identify less common ocular toxicity in patients receiving imatinib.