A Novel Acuity Testing Method

The purpose of this protocol is to develop a valid, reliable, better standardized, and more efficient test of visual acuity (ability to see fine details) for use in clinical trials. Recent improvements in computer video hardware permit calibration, characterization, and accurate rendering of eye-chart-quality letters. The computer can then be used to measure acuity. The modified binary search (MOBS) testing strategy is one method of computer-based testing. This study will compare the accuracy, precision, stability and utility of the MOBS technique with the eye chart method used in the National Eye Institute's Early Treatment for Diabetic Retinopathy Study (ETDRS). The ETDRS method is currently the gold standard for acuity testing in clinical trials. Study subjects will include NEI clinic patients between 7 and 90 years of age with or without eye disease. Eye diseases include poor visual acuity, age-related macular degeneration, cataract, optic nerve abnormality, corneal abnormality, uveitis, glaucoma, other retinal or choroid abnormality, amblyopia or other eye disease. Participants will have their vision tested in each eye using both the ETDRS eye chart method and the MOBS method. The ETDRS method will require subjects to read all the letters on the chart until they can no longer see the details. For the MOBS method, they will read a single letter at a time that will appear on the computer screen. After reading each letter, a new letter will be presented that is either bigger or smaller in size. After completing the last acuity test, participants will fill out a questionnaire regarding their preference for one test type over the other.