Fig. 2

TTO utility value (diamond), SG utility value (square) and consecutive visual acuity of both eyes set against time in months as illustrated by three patients. The abscissa represents time VA measured in months. Scale of TTO utility, SG utility and visual acuity are represented by the ordinate. It runs from 0.0 to 1.0, signifying either Snellen VA, measured TTO utility or measured SG utility. Open diamonds and open squares represent TTO and SG utility at the time of the interview. VA of the right eye is represented by filled-in circles, VA of the left eye by filled-in squares, connected by lines. VA was measured in the months preceding the interview and/or after the interview. The association between visual acuity and the decrease in visual acuity on the one hand, and measured utility on the other hand, is very weak