Effect of vision training on patients with functional visual loss

Abstract

Objective To evaluate the efficacy of vision training on functional vision loss and to analyze binocular vision characteristics in patients. Methods This retrospective study was performed at the ophthalmic center, Tianjin Eye Hospital from July 2012 to October 2013. Twenty patients with functional vision loss were enrolled, including 10 males and 10 females. The average age was 11.2±5.9 years. All patients had routine examinations that excluded eye disease, amblyopia risk factors, and systemic disease. Based on the binocular vision characteristics, all patients participated in personalized vision training. All data were statistically analyzed with a paired samplest test and Pearson correlations. Results Right eye refraction of patients ranged from +2.25 to -8.75 D ; left eye refraction ranged from +2.87 to -8.63 D. Thirteen patients had convergence insufficiency, 4 had accommodative excess, 2 had basic exophoria and 1 had divergence insufficiency. After 2 months of vision training, distance and near vision in all patients had improved to 1.0 (Z=-3.948,P<0.01;Z=-3.193,P<0.01). Near positive relative vergence (PRV) break point improved as well (t=-5.173,P<0.01). Additionally, monocular accommodative facility (MAF,Z=3.928,P<0.01), binocular accommodative facility (BAF,Z=-3.835,P<0.01), positive relative accommodation (PRA,t=4.094,P<0.01), and negative relative accommodation (NRA,t=- 4.254,P<0.01) had significantly improved. In addition, both distance vision (r=- 0.584,P<0.01 ;r=- 0.658,P<0.01) and near vision (r=- 0.451,P<0.01;r=- 0.540,P<0.01) were correlated with far exophoria and near positive relative vergence. Conclusion The occurrence of functional vision loss is apparently related to binocular vision dysfunction in these patients. Visual acuity can be improved with vision training. Key words: Functional vision loss; Binocular vision function; Accommodation, eye