Discussion
The first presentation of patients with SCH is usually to the family medicine and there are few studies on whether these patients should be evaluated for bleeding disorder. SCH is a mucosal hemorrhage and is expected in the qualitative deficiency of platelets or in platelet function disorders and coagulation factor deficiencies. In most of the non-traumatic SCH cases, the etiological causes are hypertension, diabetes mellitus and drugs. In addition, coagulation factor deficiency was detected in less than 1% of patients (10). During anticoagulant and antiaggregant usage, and hemostatic alterations as immune thrombocytopenia, congenital bleeding disorders and hematologic malignancy as leukemia, SCH was reported in previous cases[3, 9-11]. However, in these cases SCH is considered to be a part of other mucocutaneous bleeding, and patients often apply to the hematology outpatient clinic.
Hypertension, diabetes mellitus and other systemic vascular disorders play a major role in the etiology of subconjunctival hemorrhage and their prevalence increases with age. Because of this, the number of patients with SCH increases markedly over 50 years of age[12,13]. Although only spontaneous SCH were included in our study, the mean age of patients was found to be over 50 years as in previous studies. The frequency of non-traumatic SCH was reported to be more common in women in previous studies [4,6]. In our study, although SCH was seen more frequently in women, it was found to be close in frequency to each other in both sexes. In 32.7 % of cases, spontaneous SCH was recurrent in the absence of any identifiable causes or risk factors. This rate was higher than some previous studies [7]. Lens usage is an exclusion criteria in our study since it may lead to traumatic SCH. Although the usage of glasses was not considered to be a risk factor for SCH, it was determined that approximately one third of the cases were wearing glasses. The incidence of SCH is similar in both eyes.
In our country patients pay attention to the SCH rather than cutaneous bleeding. Therefore, patients may consult a doctor when they first underwent SCH despite previous recurrent other mucocutaneous bleeding. From this point we thought that the first finding of congenital bleeding disorders such as vWD may be SCH and we expected increased frequency of congenital or acquired bleeding disorders in patients with spontaneous SCH. However we showed that the prevalence of hemostatic alterations in patients with once or recurrent, spontaneous SCH is not different from that in the general population. There was also no difference between coagulation factor levels and hemostasis tests between those who had once SCH and recurrent SCH.
In few studies, no difference was found in platelet count or coagulation factor levels in recurrent SCH patients from that in the general population as in our study [6,7,10]. Although few studies have shown that homozygosity and heterozygosity for the Val 34Leu mutation of blood clotting factor FXIII is more frequent detected in SCH cases, factor XIII antigen levels were within the normal limits in all patients in our study [8,14]. Likewise in a study, there were no correlation between factor XIII antigen/activity levels and SCH[6].
40 (76.9%) of the patients included in our study had a ISTH-BAT score of 0 and no bleeding disorder was detected. When the other bleeding findings of 2 patients with type 1 vWD were evaluated, it was learned that they had bleeding attacks as epistaxis, cutaneous bleeding, menorrhagia, bleeding after tooth extraction and bleeding from minor wounds. The ISTH-BAT score of these two cases was 3 and 4, respectively. Although there seems to be a strong relationship between ISTH-BAT scores and vWD, there is no statistcal sample size to demonstrate this in our study. The necessity of evaluating patients with spontaneous SCH for bleeding disorder is stil a confusing. Although few studies suggest that spontaneous SCH should be evaluated for bleeding disorder, the conclusion to be drawn from our study is that, it is a more accurate approach to investigate bleeding disorder only in SCH patients with a history of bleeding [1,5]. It is also more cost effective.
In addition, fibrinogen level was the only statistically significant parameter in the comparison between patients with once SCH and recurrent SCH and it was lower in patients with recurrent SCH. Thrombin time was studied in five patients and all results were in normal range. Although it was statistically significant, fibrinogen levels in all patients were within normal limits and it was considered to have no clinical significance. Dysfibrinogenemia was also not considered clinically in any patient.
The first limitation of our study was the fact that the PFA-100 test was performed by appointment, and therefore the PFA-100 test could be performed at 2-3 weeks after subconjunctival hemorrhage in all patients. The second, although factor XIII antigen levels were studied in all patients, none of them had laboratory examination of factor XIII activity and Light transmission aggregometry. However, according to the data from previous studies, it is considered that this situation has no effect on the results of our study.
Patients presenting with SCH should be questioned and examined in details for common etiological risk factors such as hypertension, diabetes mellitus, fever, trauma, drug use, conjunctivitis, blepharitis, episcleritis, and corneal ulcer. If diseases such as dry eye or glaucoma are suspected, the patient should be referred to an ophthalmologist for eye examination.
In addition, in terms of other systemic bleeding findings such as recurrent epistaxis, skin and mucosal, minor post-traumatic bleeding, hematuria, gastrointestinal system bleeding, tooth extraction, post-surgical bleeding, hemarthrosis, menorrhagia, intramuscular, postpartum and central nervous system bleeding should be questioned. It should be known that acutely developing hematological diseases such as leukemias and thrombocytopenia may rarely present with SCH as a single mucosal site. It should be kept in mind that it is often associated with skin and other system bleeding. In congenital bleeding disorders, patients often have a history of previous skin and mucosal bleeding, and a history of prolonged bleeding after surgical procedures. Patients with a history of bleeding should be referred to a hematologist. However, it should be known that less than 1% of SCH patients will develop due to hematological reasons.
In conclusion, we suggest not to examine patients with spontaneous SCH for bleeding disorder, according to the data obtained from our study. Patients with spontaneous SCH should be evaluated with ISTH-BAT score instead of directly laboratory examination for bleeding disorder and evaluation for the congenital bleeding disorders of patients with other bleeding histories and high bleeding score would be more accurate.