The Clinical Significance of the Effect of Vergence on Fixation Disparity — A Preliminary Investigation*

Effects of Orthoptic Treatment on the CA/C and AC/A Ratios in Convergence Insufficiency

“…4 -6,15,27,31-35 In a well-designed study with a matched-subjects-control-group crossover design, Cooper et al 28 found that a statistically significant improvement in the vergence ranges occurred during the training period but not during the control period. In addition, Arner et al, 21 Sheedy and Saladin 22 and Sheedy 24 found that the forced vergence fixation disparity curves flattened with orthoptic treatment. Schor 23 showed a high correlation between the forced vergence fixation disparity curve and the ability to adapt to prism-induced heterophoria.…”

“…Several researchers 3,5,8,15,[21][22][23][24][25][26][27][28][29][30] have shown that CI is amenable to orthoptic exercises. In general, those patients who gain relief of their symptoms also show improved NPC and fusional convergence.…”