The association of platelet counts with development and treatment for retinopathy of prematurity – is thrombocytopenia a risk factor?

INTRODUCTION: Thrombocytes may regulate the activity of vascular endothelial growth factor (VEGF), limiting neovascularization in retinopathy of prematurity (ROP). The aim of this study was to examine the role of platelet counts, thrombocytopenia, and infections in the pathogenesis of ROP. MATERIAL AND METHODS: The study included 163 preterm infants diagnosed with ROP, comparing 76 patients who required treatment with 87 patients in whom ROP resolved spontaneously (control group). Further analysis concerned 52 patients in whom a first line treatment was sufficient to stop ROP progression, and 24 patients who required re-treatment. RESULTS: A statistically significant difference was found in the occurrence of thrombocytopenia (p = 0.015), platelet counts before the diagnosis of ROP (p = 0.008), and the presence of late-onset infection (p = 0.007). The ROC curve analysis showed that the value of platelets above 232 × 10(9)/l may stimulate spontaneous resolution of ROP. A significant difference between patients once treated and patients that required re-treatment was found in platelet count before the diagnosis of ROP (p = 0.017), platelet count before the first intervention (p = 0.013), and the number of transfusions (p = 0.042). CONCLUSIONS: The results of the study confirm the association between ROP development and its severity with thrombocytopenia. While there were no differences in the occurrence of thrombocytopenia right after the birth, its episode before the diagnosis of ROP seems to be significant for ROP development. The deficiency of platelets prior to a treatment intervention may be associated with necessity of re-treatment.