Contrast sensitivity
program

Reference: PVM-SC

Introduction
Principle
Analysis of results
Clinical applications
References
Equipment

Introduction

The evaluation of the contrast sensitivity function presents much more sensitivity than the "standard" visual acuity measurements in alterations of ocular media transparency and diseases of the retina and the optic nerve.

Principle

The tests are sinusoidal gratings whose parameters (luminance, contrast, spatial frequency) are controlled by the computer.

Each grating is first presented with very low contrast, then the contrast is progressively increased.

The patient presses a press button when he/she sees the shape of the grating bars.

Additional information :
Low contrast visual acuity charts are also available on the Vision Monitor.
Click here to see the corresponding leaflet.

example of low spatial frequency grating

example of high spatial frequency grating

Analysis of results

The results of the exam are represented as a curve (here in red) giving the contrast sensitivity versus spatial frequency.

The response curve from a normal subject shows a maximum for medium spatial frequencies (around 3 cycles per degree, corresponding to 3 white bars plus 3 dark bars viewed under an angle of 1 degree). The highest spatial frequency perceived at maximum contrast is around 30 to 45 cycles per degree, which corresponds to a 10 to 15 10th visual acuity.

The curve can be compared to inferior and superior normal limits (here in light grey).

Examples of clinical applications

contrast sensitivity curve before and after YAG laser capsulotomy	before ..................................................after
contrast sensitivity curve before and after LASIK on high myopia	1 week before ...........................1 month after 3 months after

References

DENOYER A., ROGER F., MAJZOUB S., PISELLA P.J. Quality of vision after cataract surgery in patients with prolate aspherical lens J. Fr. Ophtalmol. 2006, 29, 2, 157-163.
DENOYER A., ROGER F., MAJZOUB S., PISELLA P.J. Effect of contrast sensitivity and wavefront aberration improvements on the quality of daily vision. Journal of cataract and refractive surgery. 2007, 33, 2, 210-216.
MACAREZ R., DORDAIN Y., HUGON M. et al. Long-term effects of iterative diving on visual field, color vision and contrast sensitivity in professional divers. J Fr Ophtalmol. 2005, 28, 8, 825-831.
RISSE J.F., SAINT BLANCAT P., BOISSONNOT M., GRILLOT L. Spatial contrast sensitivity in patients with severe myopia. J. Fr. Ophtalmo 1996,19,4,27,1-7.
LIU X.W., PANG G.X., LIU X.P. et al. Static and dynamic contrast sensitivity of myopic eyes before and after laser in situ keratomileusis. Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2003, 25, 5, 585-589.
VINGOLO E.M., GRENGA P.L., IACOBELLI L., GRENGA R. Visual acuity and contrast sensitivity: AcrySof ReSTOR apodized diffractive versus AcrySof SA60AT monofocal intraocular lenses. Journal of cataract and refractive surgery. 2007, 33, 7, 1244-1247.

Vision Monitor systems compatible with this program:

Contrast sensitivity program