Abstract
Purpose :
To evaluate the binocular summation status in intermittent exotropia patients using the contrast sensitivity test.
Methods :
Eighteen patients with intermittent exotropia and eight controls were assessed with binocular summation ratio using contrast sensitivity test. Binocular summation ratio was defined as the ratio of binocular contrast sensitivity to the contrast sensitivity of the better eye. We compared binocular summation ratio at five spatial frequencies (1.5, 3, 6, 12, and 18 cycles/degree) of intermittent exotropia patients to that of normal controls.
Results :
There was a significant difference at 1.5 cycles/degree spatial frequency, intermittent exotropia patients had a lower binocular summation ratio compared to the normal control group (1.13 vs 1.47, p= 0.05). However, there was no signification differences between intermittent exotropia and control in 3, 6, 12, 18 cycles/degree spatial frequency (1.18 vs 1.08, p= 0.39, 1.52 vs 1.77, p=0.26, 1.99 vs 1.84, p=0.34, 1.80 vs 1.89, p=0.10, respectively).
Conclusions :
Intermittent exotropia patients had significantly lower binocular summation ratio at 1.5 cycles/degree spatial frequency than normal controls. Contrast sensitivity may be useful test for assessing binocular summation ratio status of intermittent exotropia patients.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.