Methods
In this retrospective study, the patients admitted to Ophthalmology and Hematology Division were enrolled between February 1, 2018, and November 30, 2019. The patients who admitted to the ophthalmology outpatient clinic due to once or recurrent SCH, underwent a complete ophthalmologic examination, including the best corrected visual acuity level, slit-lamp biomicroscopy, intraocular pressure measurement with Goldmann applanation tonometer and dilated fundoscopy. Patients who didn’t have any etiological reasons for bleeding such as conjunctivitis, episcleritis, keratitis, corneal ulcer, glaucoma, dry eye and blepharitis, were referred to the hematology outpatient clinic for evaluation of bleeding disorders.    
All patients were questioned for ocular trauma (including the usage of lenses), systemic hypertension, diabetes, cardiovascular abnormalities, fever and medications affecting platelet function or blood clotting, such as nonsteroidal anti-inflammatory drugs, aspirin, antiplatelet agents, heparin, oral anticoagulants, anti-vitamin K or non-vitamin K oral anticoagulants (NOACs), steroids, antiepileptics or antidepressants and if any, they were excluded from the study. Patients’ bleeding histories were also evaluated using a standardized bleeding assessment tool (BAT) created by International Society on Thrombosis and Hemostasis (ISTH).
Complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, factor VIII, von Willebrand factor antigen (vWF Ag), von Willebrand factor ristocetin cofactor (vWF Rco) and factor XIII antigen levels were tested from all patients meeting inclusion criterias. PFA-100 (collagen / epinephrine (C / Epi), collagen / ADP (C / ADP) and closure time (CT) were studied in available patients. Thrombin time was studied in a small number of patients. According to these laboratory results, the patients with the hemorrhagic disorders were determined and SCH with once and those with 2 or more were compared for the laboratory results.
Statistical Package for the Social Sciences (SPSS) version 15.0 was used for the analysis. The distribution of the datas were assessed using a one-sample Kolmogorov-Smirnov test. Normally distributed continuous variables were expressed as the mean±SD, skew-distributed continuous variables were expressed as the median (minimum-maximum), and categorical variables were expressed as the number and percentage. For comparison of categorical variables, Fisher’s exact test or a chi-square test was used. Differences between numeric variables were tested with Student’s t-test or a Mann-Whitney U-test, where appropriate. A p-value of less than 0.05 was considered as statistically significant.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. (Kecioren Educational and Research Hospital-08.01.2020/2027)