Reading Performance in Intermediate Age-related Macular Degeneration: Context Effects

Purpose : Our previous study of vision function in intermediate age-related macular degeneration (I-AMD) showed no significant difference in reading performance between I-AMD and age-matched control eyes (C) (Lott et al, ARVO 2016). Reading was tested monocularly using the International Reading Speed Test (IReST), which consists of paragraphs of meaningful text. The purpose of this study is to assess binocular reading in tests with and without context (IReST vs. Pepper Visual Skills for Reading Test: random letters and words [Pepper]). We hypothesize that reading performance for I-AMD will be poorer than C for the Pepper test, due to a lack of context, which places increased demand on vision.

Methods : Sixteen people with I-AMD (mean age =76.1 yrs), and 13 C individuals (mean age =74.7 yrs) participated. All had binocular acuity better than 20/32 (≤ 0.20 logMAR). The IReST and Pepper rates (correct words per minute [wpm]) were the dependent variables. Vision function (SKILL Card: near high contrast acuity [SKL] and the impact of low luminance and contrast on acuity [SKILL Score; SKDark–SKL]), cognitive status (Montreal Cognitive Assessment: MOCA), speech production rate (letters per second for reciting the alphabet), demographic information, and cataract status were the independent variables.

Results : Binocularly measured IReST reading rates were similar for the I-AMD and C groups (mean = 186.6 vs. 190.9 wpm, respectively). However, Pepper rates were significantly lower in I-AMD than C (mean = 93.2 vs. 104.4 wpm). The groups did not differ in SKL, age, sex or MOCA. SKILL score was significantly different for the two groups (0.63 vs 0.54 log units), and speech production rate was higher in I-AMD (4.1 vs. 3.3 letters per second). The prevalence of cataract surgery was also higher in the I-AMD group (56.3% vs. 15.4%). Separate linear regression analyses predicting IReST and Pepper from the independent variables confirmed these findings. For IReST, only speech production was a significant predictor of reading. For Pepper, SKILL Score, speech production and AMD category were significant predictors (p<0.001).

Conclusions : In agreement with our previous research using monocular testing, I-AMD and C read at similar rates using meaningful text, but without context, those with I-AMD are at a greater disadvantage. Of particular note is the dramatic difference in cataract surgery rates between the two subject groups.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.