Format

Send to

Choose Destination
Invest Ophthalmol Vis Sci. 2014 Oct 28;56(1):139-49. doi: 10.1167/iovs.14-15224.

The effect of Bangerter filters on binocular function in observers with amblyopia.

Author information

1
State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
2
School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada Department of Optometry and Vision Science, Faculty of Science, The University of Auckland, Auckland, New Zealand.
3
School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China.
4
Department of Ophthalmology, McGill University, Montreal, Canada.

Abstract

PURPOSE:

We assessed whether partial occlusion of the nonamblyopic eye with Bangerter filters can immediately reduce suppression and promote binocular summation of contrast in observers with amblyopia.

METHODS:

In Experiment 1, suppression was measured for 22 observers (mean age, 20 years; range, 14-32 years; 10 females) with strabismic or anisometropic amblyopia and 10 controls using our previously established "balance point" protocol. Measurements were made at baseline and with 0.6-, 0.4-, and 0.2-strength Bangerter filters placed over the nonamblyopic/dominant eye. In Experiment 2, psychophysical measurements of contrast sensitivity were made under binocular and monocular viewing conditions for 25 observers with anisometropic amblyopia (mean age, 17 years; range, 11-28 years; 14 females) and 22 controls (mean age, 24 years; range, 22-27; 12 female). Measurements were made at baseline, and with 0.4- and 0.2-strength Bangerter filters placed over the nonamblyopic/dominant eye. Binocular summation ratios (BSRs) were calculated at baseline and with Bangerter filters in place.

RESULTS:

Experiment 1: Bangerter filters reduced suppression in observers with amblyopia and induced suppression in controls (P = 0.025). The 0.2-strength filter eliminated suppression in observers with amblyopia and this was not a visual acuity effect. Experiment 2: Bangerter filters were able to induce normal levels of binocular contrast summation in the group of observers with anisometropic amblyopia for a stimulus with a spatial frequency of 3 cycles per degree (cpd, P = 0.006). The filters reduced binocular summation in controls.

CONCLUSIONS:

Bangerter filters can immediately reduce suppression and promote binocular summation for mid/low spatial frequencies in observers with amblyopia.

KEYWORDS:

amblyopia; binocular vision; contrast sensitivity; psychophysics

PMID:
25352120
DOI:
10.1167/iovs.14-15224
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center