Comparison of hemorrhagic complications of warfarin and clopidogrel bisulfate in 25-gauge vitrectomy versus a control group.

PURPOSE: To estimate the risk of hemorrhagic complications associated with 25-gauge pars plana vitrectomy (PPV) when warfarin (Coumadin; Bristol-Myers Squibb, New York, NY) or clopidogrel (Plavix; Bristol-Myers Squibb) are continued throughout the surgical period, as compared with a control group. DESIGN: A single-center, retrospective, cohort study of 289 consecutive patients receiving either warfarin therapy or clopidogrel therapy or neither of those therapies who underwent 25-gauge PPV. PARTICIPANTS: Included were 61 patients (64 eyes; 64 PPV procedures) in the warfarin group and 118 (125 eyes; 136 PPV procedures) in the clopidogrel group. Warfarin patients were subdivided into 4 groups by international normalized ratio (INR). A control group included 110 patients (110 eyes; 110 PPV procedures) who were not receiving warfarin or clopidogrel. METHODS: Retrospective chart review for which the criteria included: 25-gauge PPV, minimum age of 19 years, warfarin or clopidogrel use, and, if taking warfarin, an INR obtained within 5 days of surgery. MAIN OUTCOME MEASURES: Incidence of intraoperative and postoperative hemorrhagic complications. RESULTS: The most common indications for anticoagulation therapy included: atrial fibrillation (38%), valvular heart disease (17%), and thromboembolic disease (16%). The most common indications for antiplatelet therapy included: cardiac stent (49%), coronary artery bypass grafting (24%), and history of transient ischemic attack (16%). No patient experienced anesthesia-related hemorrhagic complications resulting from peribulbar or retrobulbar block. Transient vitreous hemorrhage occurred in 1 (1.6%) of 64 PPV procedures in the warfarin group (P = 0.6531), 5 (3.7%) of 136 PPV procedures in the clopidogrel group (P = 1.0), and 4 (3.6%) of 110 PPV procedures in the control group. No choroidal or retrobulbar hemorrhages occurred in any patient. CONCLUSIONS: The rate of 25-gauge PPV hemorrhagic complications in patients who underwent systemic anticoagulation or who were receiving platelet inhibitor therapy is extremely low. Given the risks associated with stopping these therapies, the authors recommend that patients continue their current therapeutic regimen without cessation.

An unusual case of high altitude-like retinopathy caused by anemia and thrombocytopenia at recreational altitude.

PURPOSE: To report an unusual presentation of high altitude-like retinopathy at recreational altitude after chemotherapy-induced anemia and thrombocytopenia. METHODS: Case report. RESULTS: A 43-year-old man undergoing chemotherapy for testicular cancer traveled to an altitude of 2,930 m and subsequently developed significant visual deficit in his right eye and was later diagnosed with bilateral severe high altitude-like retinopathy pathology with associated retinal hemorrhages. CONCLUSION: Altitude-related illnesses like high-altitude retinopathy result from rapid physiologic adaptation to altitude-induced hypoxia. These illnesses are typically experienced at altitudes above 3,000 m, with high-altitude retinal hemorrhages observed above 4,270 m. The patient participated in no strenuous physical activity but had severe enough retinal hypoxia from chemotherapy-induced anemia and thrombocytopenia that he experienced visually significant retinal hemorrhages. The occurrence of high-altitude retinopathy in such patients could portend the development of high-altitude cerebral edema at lower altitudes than traditionally reported and without exposure to known risk factors. Therefore, funduscopic examination should be performed on patients with anemia and thrombocytopenia who are complaining of decreased vision after traveling at high altitude.