Abstract
Reading is a primary problem for low vision patients and a functional endpoint for eye disease. However, there is limited agreement on reading assessment methods for clinical outcomes. Many clinical reading tests lack standardized materials for repeated testing and cannot be self-administered, which limit their use for vision rehabilitation and home assessment. We compared three different reading measurements that attempt to address these limitations. Normally-sighted participants (N=13) completed a MNREAD test (Legge et al.,1993), and two different 2AFC reading tasks in counterbalanced order. In one 2AFC task, participants identified whether 5-letter pentagrams, syntactically matched to English, were words or non-words. In the other 2AFC task, participants indicated whether four-word sentences were logically true or false (Crossland et al., 2008). The font size and exposure duration was controlled by a quick Reading algorithm (Lu et al., 2016) that maximized the expected information gain from each trial and updated the posterior distribution of the parameters of the reading function. All lexical stimuli were presented on a computer monitor as black letters on a white background and 2AFC stimuli were pre and post masked with a sequence of Xs. The data from each experiment were fit by an exponential function with parameters for reading acuity (logMAR), acuity reserve and maximum reading speed (words per minute). In all cases, reading speed increased quickly as an exponential function of letter size, in line with previous studies. However, the parameters for the word/non-word, true/false reading and MNREAD methods were significantly different and were not correlated among tasks. These results suggest that these different reading tasks measure different aspects of reading behavior. Evaluating reading performance is an important clinical endpoint and a key quality of life indicator. However, the most effective test that is clinically meaningful is not clear.
Meeting abstract presented at VSS 2017