Optometry Club

Roth's spots are retinal hemorrhages with white or pale centers composed of coagulated fibrin. They are usually caused by immune complex mediated vasculitis often resulting from bacterial endocarditis. Roth's spots are named after Moritz Roth. These "white-centered" hemorrhages originally described in patients with bacterial endocarditis, are not specific for that disease. They probably reflect microinfarcts, just like cotton wool spots, and occur in a litany of disorders, including essential hypertension, Leukemia, diabetes,ischemic events, pernicious anaemia , HIV, connective tissue disease Behçet's disease, viremia, and hypercoagulable states. While Roth spots are not specific for endocarditis, discovering them in a patient who has other suggestive features of endocarditis constitutes strong support for the diagnosis.

K-readings, also known as keratometry readings or K-values, are measurements of the curvature of the cornea (the clear, dome-shaped structure at the front of the eye). They are expressed in diopters (a unit of measure for refractive power) and are used to determine the appropriate lens prescription for eyeglasses or contact lenses and to plan refractive corneal surgeries, such as LASIK (laser-assisted in situ keratomileusis). In refractive corneal surgeries, K-readings are used to measure the shape and curvature of the cornea and to determine the amount of correction needed to correct vision problems. They are also used to determine the appropriate size and shape of the laser treatment or other surgical technique that will be used to reshape the cornea. K-readings are usually taken using a keratometer, a specialized instrument that measures the curvature of the cornea. They are usually taken before and after surgery to assess the success of the procedure and to ensure that the cornea h