Does a retinoscope actually matter in low vision rehabilitation if the patient’s vision is so poor?
I have found that a retinoscope, yes that dusty instrument you only use at health fairs, is invaluable in low vision rehabilitation. Firstly, the typical low vision patient has an etiology where their best field is not centrally, and every auto-refractor only works if the patient is staring straight ahead! Find out with a hand-held eye chart or observing the patient’s eccentric viewing position where that best field is. If it is the inferior field that is the best, raise the patient in the exam chair and measure that field, telling them why. I have found on many patient encounters, this is key to getting the right starting point for your trial frame refraction. In doing a retrospective study where I work at an HMO, I found that in 25 patients, this was an average of 1.55D more plus than the auto-refractor found. In the eventual near prescription, this accounted for a 3 to 4 line improvement in near and computer-monitor visual acuity. Don’t have the patient eccentrically view instead…they will probably do so at a more extreme angle than what is necessary, and of course the VA falls off at that angle.
Gary Asano, OD, FAAO
Council Member, AOA VRS
Vice Chair, COA LV Rehabilitation Section