Abstract
Purpose :
Age related macular degeneration (AMD) is a progressive degenerative disease of the retinal pigment epithelium, Bruch’s membrane, and choriocapillaris. Reading difficulty is a common complaint in AMD patients, normal elderly patients, and patients with decreased visual acuity. The purpose of this study was to investigate reading rates in age-matched normal and early to intermediate AMD patients with similar acuity.
Methods :
Twenty-one subjects took part in this study (11 AMD (age 78.4 ± 7.49) and 10 normal controls (age 75.2 ± 5.75) p = 0.53). All subjects had a complete eye exam (VA, fields, OCT, fundus photos). The logMAR visual acuities for the test eye were not significantly different between the groups (AMD = 0.09 ± 0.098 and Control = 0.03 ± 0.043, p = 0.127). The AMD patients were grades 2 – 4 according to the simplified AREDS scale (average = 3.3 ± 0.65) and the control patients did not have drusen within 2 disc diameters of the fovea. The Tobii TX300 Eye Tracker was used to record eye movements (saccades, fixations, regressions, and blinks) during reading. The Wilkins Rate of Reading Test was used to determine reading rate under monocular and binocular conditions. The words were equivalent to a 20/50 Snellen letter at 60 cm. The subjects wore their optimal correction for the reading distance.
Results :
The reading rates for the test eye (AMD = 116.2 ± 22.98 wpm, Control = 146.9 ± 23.01 wpm, p = 0.01) and under binocular conditions (AMD = 122.0 ± 23.47 wpm, Control = 152.6 ± 15.45 wpm, p = 0.004) were significantly slower for the AMD patients. There were no significant differences between AMD patients and normal controls for saccade amplitude, fixation time, number of saccades or fixations, number of regressions, or blinks (all p values > 0.05). The average saccade velocity was greater for the AMD patients (AMD = 70.9 ± 21.18 deg/sec, Control = 54.0 ± 11.23 deg/sec, p = 0.047).
Conclusions :
The reading rate for early to intermediate AMD patients is slower than age-matched normal control patients with similar acuity. The decrease in the reading rate cannot be explained by eye movement parameters.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.