LAUSR

Dear Editor, We have recently observed a peculiar presentation of hemorrhages in patients with retinal vein occlusion (RVO). In addition to the expected scattered intraretinal flameshaped hemorrhages and cystoid macular edema (CME), we noticed that in some areas, hemorrhages appeared in a blood-fluid level (BFL) appearance (Fig. 1). This finding was described in up to 55.7% of patients with branch retinal vein occlusion [1] and 7% in patients with central retinal vein occlusion, which is much more common than in other causes of CME, such as diabetic retinopathy (1.8%) [2]. The clinical relevance, as well as the reason for the occurrence of BFL within cystoid spaces, is not totally understood. It has been suggested that the presence of intraretinal fluid leads to disruption of small capillaries in the outer plexiform layer with subsequent bleeding into the cystoid space [3]. The studies that sought to correlate visual prognosis with this finding presented conflicting trends. Imamura et al. [1] and Muraoka et al. [4] raised the possibility of worse visual outcomes in patients with RVO associated with hemorrhages within cystoid spaces. On the other hand, Reyes et al. [2] studied 472 eyes and concluded that the presence of blood inside the cystic spaces was not related to worse visual outcome or prognosis; however, the study was conducted in the pre-optical coherence tomography (OCT) and antiangiogenic therapy era, which is a limiting factor. In addition, it is inferred that recent well-controlled randomized clinical trials investigating the treatment of RVO (including studies that investigated the safety and efficacy of retinal photocoagulation, intravitreal steroid treatment, and antiangiogenic therapy for the treatment of RVO) did not include BFL as a variable in their analyses. Therefore, we would like to bring this issue to light in the hope of establishing a new biomarker and consequently improving the management of retinal vascular diseases. We believe that if further studies correlate the importance of this clinical finding to the visual outcomes, or if previous clinical trials stratify these data and analyze the clinical relevance of BFL, we will be able to illuminate new rationales for the treatment and follow-up of the patients with RVO. In addition, we encourage readers to investigate the pathophysiology of this finding for better elucidation of the disease and prognosis. * Gabriel Castilho Sandoval Barbosa [email protected]