Contrast sensitivity in XXXX . IV. Assessment of vision using vertical and horizontal gratings and optotypes at different contrast levels.

@entity1 @entity432 @entity4457
The contrast sensitivity of 49 amblyopic @entity1 (mean age 9 years) was measured in the beginning and at the end of a treatment period using both vertical gratings and optotypes (LH-4 contrast test) at 2, 3, 5 and 75% contrast. The contrast sensitivity of 37 @entity1 was also measure using horizontal gratings. The contrast sensitivity of the dominant eyes measured with vertical gratings was generally higher than when measured with horizontal gratings. The difference was statistically significant at spatial frequencies 1 and 6 c/deg. A similar difference was present in the amblyopic eyes only at the spatial frequency 1 c/deg both before and after the treatment. Individual variation was great; in a given @entity1 the relationship between the two measurements varied from one spatial frequency to the next. It has been shown in earlier investigations that contrast sensitivity measurements using gratings reveal important new information in the study of @entity4457 . Both tests, used in this investigation, measure visual function in the low contrast domain and improve follow-up of the changes in vision during treatment of @entity4457 when used in addition to visual acuity measurements. Low contrast optotype test seems to measure contrast sensitivity in @entity4457 closely similarly to the grating test. The slight difference in detecting a ' @entity432 ' at the intermediate spatial frequencies needs further study.
