A comparison of the optical Stiles-Crawford effect and retinal densitometry in a clinical setting.

PURPOSE

To compare the measurement of the optical Stiles-Crawford effect (SCE) to the densitometry of cone visual pigments in a clinical setting. Both tests provide information on outer retinal integrity, but the optical SCE can be performed in far less time.

METHODS

Images acquired with a custom-built scanning laser ophthalmoscope were used to assess visual pigment density and optical SCE. Visual pigment density was regarded as the "gold standard." More than 100 patients with suspected, and some with known, outer retinal pathology were tested. The group included cases of central serous detachment, cone dystrophy, Stargardt's disease, Best's disease, and retinitis pigmentosa.

RESULTS

Parameters of the optical SCE of 25 healthy subjects and 106 patients were taken through a stepwise linear regression to predict density. The correlation between predicted density from the optical SCE and the measured density was 0.82. The sensitivity of the optical SCE to detect decreased density was 96%. When only the foveal reflectance was considered, sensitivity was still 84%

CONCLUSIONS

The optical SCE is a sensitive and fast method for detecting cone photoreceptor disturbances.