Impaired fusional vergence facility in young adults with dry eye syndrome

Symptoms associated with dry eye and those related to vergence and accommodative disorders exhibit considerable overlap, suggesting a possible dysfunction in vergence/accommodative performance in individuals with dry eye.

This cross-sectional study aimed to assess the accommodative and binocular vision performance in young adults with dry eye syndrome compared to a control group.

Forty individuals with dry eye syndrome and 40 healthy controls were enrolled. Each participant underwent a comprehensive ocular examination including visual acuity measurement, refraction, slit-lamp examination, tear film evaluation, and assessments of accommodative and binocular vision performance.

The mean age of the participants was 22.70 ± 2.40 years in the dry eye group and 22.51 ± 2.21 years in the control group (p = 0.720). Twelve (30%) and thirteen (32.5%) participants in the dry eye and control groups were male, respectively (p = 0.550). No statistically significant differences were found in best-corrected visual acuity, sphere, cylinder, or spherical equivalent refraction between the dry eye and control groups (all p-values > 0.05). The median vergence facility in the dry eye group was significantly lower than that of the control group (9 vs. 15 cycles per minute p < 0.001). The analysis indicated no statistically significant differences between the groups regarding other measures, such as distance and near phoria, near point of convergence break and recovery, distance and near positive and negative fusional vergence amplitudes, stereoacuity, and accommodative parameters. Furthermore, a statistically significant negative correlation was identified between the vergence facility and the ocular surface disease index (r = -0.285, p = 0.011), while a significant positive correlation (r = 0.288, p = 0.010) was noted between the vergence facility and the tear break-up time.

Dry eye negatively affects vergence facility in young adults. This vergence dysfunction contributes to the symptoms reported by dry eye patients and shows a significant positive correlation with tear film instability.