Longitudinal cohort study of patients with birdshot chorioretinopathy II: color vision at baseline

To describe color vision at the baseline examination of 80 participants in a longitudinal cohort study of birdshot chorioretinopathy and to identify relationships between color vision and visual acuity, symptoms, and ophthalmic signs.

Single center cross-sectional study.

Color vision was evaluated with the desaturated Lanthony 15-Hue test. Relationships were sought between the square root of the color confusion scores (CCS) and the following factors: best-corrected visual acuity (BCVA), symptoms, cataract, vitreous inflammatory reactions, retinal vasculitis, cystoid macular edema (CME), and birdshot lesion characteristics.

When compared with published, age-matched normal control subjects, 49 patients (61.3%; 76 eyes [47.5%]) had abnormal CCS values. Abnormal CCS values were found in nine of 51 phakic eyes (18%) with normal BCVA (>or=1.0) and without cataract. Although most eyes did not have classifiable defects, 30 eyes (18.8%) had tritan (blue-yellow) defects (88% of eyes with classifiable defects). With the use of multivariate analyses, there were significant associations between increased CCS values and the symptoms of altered color vision (P = .005) and altered contrast sensitivity (P = .015). There was a significant, but weak, relationship between CCS values and birdshot lesion morphologic condition (P = .049), but no relationships were found with other lesion characteristics or with vitreous inflammatory reactions, retinal vasculitis, or CME.

The Lanthony 15-Hue test provides an objective technique to assess complaints of altered color vision in people with birdshot chorioretinopathy. Color vision can be abnormal in eyes with normal visual acuity; therefore, this parameter may be useful as an additional measure for monitoring the disease.