BY PAYING proper attention to certain clearly defined changes in the retina, it is possible for the general practitioner, as well as the ophthalmologist, to make those observations which will permit him to estimate, within reasonable limits of accuracy, the expected level of a patient's diastolic blood pressure, commensurate with these changes.
It is well known that during the course of hypertension remissions in blood pressure figures occur. During the periods of exacerbation, on the other hand, there take place such profound, irreversible changes in the appearance of the retinal vessels, particularly the arterioles, that they remain as permanent signs, to be read by him who will. So true is this that, although intercurrent coronary thrombosis will markedly lower the sphygmomanometer readings, it will alter not at all the retinal vessel changes developed during the high diastolic levels that were reached previously. Once a persistently elevated diastolic pressure has existed,