The Effects of Virtual Colonoscopy on Intraocular Pressure

Glaucoma is a complicated disease in which damage to the optic nerve leads to progressive, irreversible vision loss. Glaucoma is the second leading cause of blindness and associated with elevated intraocular pressure (IOP) as a major risk factor. IOP is influenced by many factors, including ethnicity, heredity, various chemical substances (existing body and external body like drugs), physical changes (postures, neural and vascular autoregulation) and more. Virtual colonoscopy is a common screening test for the early detection and diagnosis of colon cancer. The test is performed by computed tomography (CT) after inflating the colon with carbon dioxide (CO2) gas. The procedure is performed by inserting a Foley catheter through the anus. As a result of gas inflating of the bowel, consequently, there is an increase in the abdominal pressure. Raising intra-abdominal pressure may cause a rise in intraocular pressure. The aim of this research is to examine the changes in IOP before and after the virtual colonoscopy, with the aim to improve the understanding of the relationship between intra-abdominal pressure and IOP. The study will include 100 patients, men and women, that are scheduled for virtual colonoscopy test both in a hospital and in ambulatory.