A Study of the Spectrum of Visual Function and Choroidal Structure in Patients with Histiocytosis
The purpose of this research study is to understand more about how histiocytosis affects the choroid, which is a layer of blood vessels inside the eye. About 5-10% of patients with histiocytosis will have obvious disease in their choroid and this can result in problems with vision. In addition, in our experience, many patients with histiocytosis (40%) tell us that they have problems with their vision but without knowledge of disease in their eyes. In a small group of patients with histiocytosis, we used a special type camera to take images of the eye. This camera does not touch the eye and uses light to make high-resolution images of the inside of the eye including the choroid, in a matter of just minutes. This showed us that the majority of histiocytosis patients we looked at had abnormal thickening of their choroid (and an abnormally thick choroid can change vision in a number of ways). This was an important finding because it suggests that histiocytosis is affecting the eye, and specifically the choroid, in ways that we did not know about and have not be able to previously detect.
For this study, we are going to perform this type of eye imaging (called OCT) to investigate how many patients with histiocytosis have a thick choroid, whether the blood vessels of the choroid look different and whether these findings are linked to certain features like the type of histiocytosis or particular genetics or otherareas in the body that have disease. Finally, we would also like to explore one other possibility: whether the choroid becomes less thick when patients with histiocytosis are on treatment for their disease. With all of this information, we can begin to figure out what parts and functions of the choroid are affected by histiocytosis and the types of effects this has on vision. We believe this study will generate a framework that is needed for future research on how we can detect, understand and treat problems with the choroid in histiocytosis