Anterior ischemic optic neuropathy complicating redo coronary artery bypass grafting Redo koroner arter baypas cerrahisi sonrasi gelişen anterior iskemik optik nöropati

Anterior ischemic optic neuropathy (AION) is a rare cause of visual loss in patients who have undergone nonoptical surgery. The incidence of AION, in cardiac surgery differs between 0.06% and 1.3%. AION following cardiac surgery is a multifactorial disease. The etiology includes prolonged cardiopulmonary bypass (CPB) time and myocardial ischemia, the risk for micro-embolization during aortic cannulation and clamping, the CPB-related infl ammatory response, excessive haemodilution, hypo- or hypertension, systemic hypothermia, and the perioperative irregular blood sugar values. A 50-year-old man, with a history of diabetes mellitus (DM), hypertension, coronary artery bypass grafting surgery (CABG) in 1999, underwent a redo CABG in our department. On the fi rst postoperative day, the patient complained of a sudden, painless, almost total loss of vision of his right eye. In the neurological examination, almost total loss of vision in the lower-half of the visual fi eld of right eye was observed, and no other neurological fi nding was observed. The preoperative haemoglobin (Hgb) was 12.8 g/dL with a haematocrit (Htc) of 40.0%; and the erythrocyte sedimentation rate (ESR) was 40 mm/h. The patient’s Htc levels were kept 19.1-21.6% during the operation. The preoperative Haemoglobin A1c was 6.6%. The CPB time was prolonged due to the multiple coronary artery revascularization. AION is an important cause of visual loss and any recovery of vision is unusual and no treatment has been shown to aid recovery. It usually affects patients over the age of 50 years. In this case, we believe that the main etiological factors in the occurence of AION were low Hgb and Htc levels, the prolonged CPB time, and DM.