Purchase this article with an account.
D. C. Fletcher, R. A. Schuchard, J. Wada, G. M. Villani; Central Field Defects and Reading Errors in Low Vision Patients Analyzed With Binocular Low Tech Tests. Invest. Ophthalmol. Vis. Sci. 2010;51(13):3066.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To assess central visual field and reading performance in patients referred for low vision rehabilitation using low tech, inexpensive testing protocols that provide binocular vision testing.
249 patients referred for low vision rehabilitation had binocular vision assessed by: visual acuity (VA) with the ETDRS chart at 1 meter; central visual field testing for dense and relative scotomas using the California Central Visual Field Test (CCVFT); contrast sensitivity testing with the Mars chart; and reading performance evaluated with the SKRead chart in their initial evaluation. Scotomas within 2.5 degrees of the PRL (fixation) to either superior, right, left or inferior margins were noted. Right or left sided errors for all sizes of font readable were noted.
Patient age median/range was 83/9 - 100 years and 59% were female. 78% had a maculopathy, with several other diagnoses in the remaining 22%. Visual acuity median/range was 20/120 and 20/20 - 20/4000. 72% (179/249) demonstrated a bordering scotoma of which 39% (96/249) had a dense scotoma and 36% (90/249) had only a relative scotoma. Binocular PRL scotoma borders were: Right - 40% (100/249); Left - 31% (78/249); Right and Left - 16% (39/249); Superior - 45% (113/249); and Inferior - 24% (61/249). 12% (31/249) had a ring scotoma pattern with fixation surrounded by scotomas on all sides. Total SK Read errors were significantly (p<0.05) related to visual acuity but not contrast sensitivity. SK Read testing showed errors on the right side of words were significantly higher in patients with scotomas to the right and both sides of fixation as well as with ring scotomas while left errors were significantly (p<0.05) higher only in patients with left scotomas.
With inexpensive low tech testing methods, the majority of patients referred for low vision rehabilitation demonstrated binocular scotomas near their fixation. There was also a significant correlation between the location of scotomas and the type of reading errors made. Binocular scotoma prevalence and locations is remarkably similar to previous monocular studies done with more expensive scanning laser ophthalmoscope (SLO) macular perimetry. Knowledge of the presence of scotomas and influence on reading accuracy is valuable to the low vision rehabilitation clinician.
This PDF is available to Subscribers Only