Improvement in colour vision parameters following successful trabeculectomy

Abstract

To determine whether colour vision improves following reduction of intraocular pressure (IOP) in glaucoma patients. The medical records of 29 glaucoma patients (41 eyes) were reviewed. Inclusion criteria required subjects to have made more than four visits to the Glaucoma Service Laboratory and to undergo a thorough eye examination including a Farnsworth-Munsell 100-hue colour vision test and Goldmann tonometry before and after pressure lowering. Colour vision parameters of total error score (TES), yellow-blue score (YBS) and red-green score (RGS) were measured. The study group consisted of 21 eyes of glaucoma patients who underwent uncomplicated trabeculectomy with an IOP reduction of >/= 20% from baseline. The control group consisted of 21 eyes of glaucoma patients matched for age and colour vision, who received medication and/or underwent surgery with a post-intervention IOP reduction of < 20% from baseline. The primary outcome was a comparison of pre- and post-intervention colour vision parameters between the two groups. There was a statistically significant improvement in TES (43 +/- 44, p < 0.001), RGS (19 +/- 27, p = 0.0077) and YBS (23 +/- 29, p = 0.0007) in the study group compared with the control group. The improvement in TES (r = 0.52, p < 0.001), RGS (r = 0.55, p < 0.001) and YBS (r = 0.40, p = 0.008) was correlated with the percentage of IOP reduction. There was no statistically significant difference between improvement in Y-B and R-G scores in the study group. Intraocular pressure reduction of >/= 20% post-trabeculectomy was associated with an improvement in colour vision. Colour vision tests may be useful as an adjunctive outcome measure for therapeutic interventions.