Reading speed in geographic atrophy: Change over time and relation to patient-reported functioning

Abstract

 

Purpose

 

Maintaining reading ability is important to patients with macular disease and particularly relevant to those with central visual field loss. Reading ability can be measured using objective performance assessment or through a patient-reported outcome measure, which provides insight into the effect of reading impairment on daily life. This study examined objectively measured reading speed and its relationship to patient-reported independence performing everyday activities that require reading

 

Methods

 

This study included secondary analyses of data from MAHALO, a multi-center, randomized, sham-controlled, phase 2 trial that evaluated lampalizumab for geographic atrophy (GA) secondary to age-related macular degeneration. Subjects received sham or lampalizumab injections in 1 eye monthly or every other month for 18 mo. Reading speed, the number of correctly read words per minute (wpm), was measured using MNREAD acuity charts with continuous-text representing everyday reading. Reading fluency was defined as ≥80 wpm. Patient-reported reading independence was measured by the 7-item interviewer-administered Functional Reading Independence (FRI) Index. For each reading activity (eg writing checks or reading written print), the patient was asked if they performed the activity during the past 7 days and the extent to which they required low vision aids, adjustments in the activity, or help from another person. Scores ranged from 1 (unable to do) to 4 (totally independent). Both reading assessments were binocular and measured at baseline and every 6 mo. Treatment arms were collapsed for these analyses (N=100).

 

Results

 

At baseline, the correlation (Spearman’s r) between objectively measured reading speed and functional reading independence was 0.72 (P<0.001). Over 18 mo, average reading speed declined from 105 wpm (n=95) at baseline to 82 wpm (n=80), an average decrease of 26 wpm (SD 44). Fluent readers had higher mean FRI Index scores than less fluent readers at both baseline and 18 mo (both P<0.0001; Table).

 

Conclusions

 

In MAHALO, patients with GA had substantial declines in reading speed over 18 mo. Objectively measured reading speed was strongly correlated with patient-reported functional reading independence. These data support the use of both objectively measured reading speed and patient-reported functional reading independence as outcome measures in clinical trials of patients with GA.