Eye Signs in Critically Ill Patient

Abstract

The eye is a special sense organ, is situated in a skeletal cavity, the orbit, the walls of which help to protect it from injury.it is made up of three coats or tunics: the outer fibrous layer of connective tissue, the middle vascular layer and the inner neural layer. The eyeball, the peripheral organ of vision, takes in information from the environment in the form of light and send it through optic nerve into the cerebral cortex where analyzes and interprets it. This process of sight and visual perception involves a complex system of structures, each of which is designed for a specific purpose. The organization of each structure enables it to perform its intended function. The human eye, as an organ, can offer critical clues to the presence of systemic illness. Ocular changes are common in the early course of many systemic diseases. Diabetes mellitus (DM), commonly referred to as diabetes, is a group of metabolic diseases in which there are high blood sugar levels over a prolonged period. Diabetic retinopathy is a potentially blinding complication of diabetes mellitus and it is the most common micro-vascular complication of diabetes mellitus. Studies indicated association of the presence of diabetic retinopathy and increased overall-mortality and cardiovascular events both in type 1 and type 2 diabetes. Therefore, an interdisciplinary approach of physicians, endocrinologists, and ophthalmologists is needed for optimal care. Hypertension (HTN or HT), also known as high blood pressure or arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated. Hypertension usually does not cause symptoms initially, but sustained hypertension over time is a major risk factor for hypertensive heart disease, coronary artery disease, stroke, aortic aneurysm, peripheral artery disease, and chronic kidney disease. Hypertension acts as a silent killer many years before overt end organ damage is clinically apparent. Poorly controlled systemic hypertension causes damage to the retinal microcirculation, so that recognition of hypertensive retinopathy may be important in cardiovascular risk stratification of hypertensive patients. Coma is a state of unarousable unconsciousness due to dysfunction of the brain's ascending reticular activating system, which is responsible for arousal and the maintenance of wakefulness. Eye examination for any comatosed patient is important as eye signs can offer critical clues for determination of the causes and reversibility (prognosis) of neurological impairment. There are little means by which a clinician can assess and prognose clinical course in severe cases of disorders of consciousness, limiting effective care of patients. With technological progress, we have been able to measure spontaneous eye movements or ocular responses to stimuli with greater accuracy and precision.