Correlation between reading skills and different measurements of convergence amplitude

Purpose. To find correlations between convergence amplitude and reading ability, as assessed in various methods. Methods. Convergence of 66 children aged 8-10 years was evaluated using 1) Non-accommodative target at near and distance; 2) A near computerized stereogram; and 3) Measurement of near point of convergence (NPC). Reading ability was examined by: 1) a reading comprehension test and 2) the Developmental Eye Movement Test (DEM), which evaluates saccadic speed and accuracy. Results. Convergence amplitudes on a distant target and on a near stereogram were correlated with the DEM score (P = 0.005/0.02, r = -0.38/-0.32 and P < 0.001/0.002, r = -0.53/-0.53 for break/recovery respectively), while NPC and convergence on a near non-accommodative target did not. Reading comprehension test score was not correlated with any of the convergence measurements. Conclusion. Convergence amplitude measured while accommodation is controlled was correlated with the DEM score, which evaluates saccadic speed and accuracy. Further study to evaluate whether improvement in vergence control improves DEM scores is needed.