Quantitative anomaloscopy and optical coherence tomography scanning in central serous chorioretinopathy

Dyschromatopsia is a prominent sign in a variety of central retinal diseases, such as central serous chorioretinopathy (CSC). The changes in colour vision may be due to either optical or neuronal factors in the diseased retina. The relative contribution from the two causes is unknown, but may be elucidated by obtaining knowledge of the anatomical derangement in the diseased retina in CSC.

Twenty-six normal persons had their colour vision tested using the Tomey anomaloscope. The calculation of setting range (SR) and central mean point (CMP) for Rayleigh match and Moreland match was optimized, and normal ranges for these values were defined. Subsequently 24 patients with CSC were examined by anomaloscopy and optical coherence tomography scanning, and the measures of colour vision were related to the anatomical changes observed on the scans.

The algorithm for calculating SR and CMP which is integrated into the Tomey anomaloscope could be considerably improved to increase sensitivity and reproducibility of these measures. Fifteen patients had abnormal colour vision. Nine patients had pseudo-protanomaly, seven patients had pseudo-tritanomaly, and three patients had abnormalities in both matches. There was no relation between these colour vision abnormalities and the anatomical derangement as seen by OCT in the diseased central retina.

The findings argue against the notion that the density of retinal cell nuclei, the orientation of photoreceptors, or the size of the central serous detachment are related to the colour vision abnormalities in CSC. The question of whether these abnormalities are due to optical or neuronal factors remains open.