Masakazu Hirota1, Hiroyuki Kanda1, Takao Endo2, Tibor Karl Lohmann1,3, Tomomitsu Miyoshi4, Takeshi Morimoto1, Takashi Fujikado5. 1. Department of Applied Visual Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan. 2. Department of Ophthalmology, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan. 3. Department of Ophthalmology, University Hospital Aachen RWTH Aachen University, Aachen, Nordrhein-Westfalen, Germany. 4. Department of Integrative Physiology, Osaka University Graduate School of Medicine, Suita-shi, Osaka, Japan. 5. Department of Applied Visual Science, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan. fujikado@ophthal.med.osaka-u.ac.jp.
Abstract
PURPOSE: To determine the relationship between re-reading the same line and saccadic disconjugacy in patients with convergence insufficiency-type intermittent exotropia [CI-type X(T)]. METHODS: Eight patients with CI-type X(T) and ten healthy orthophoric individuals were studied. Video-oculography was used to assess the eye movements during the reading of a Japanese novel displayed on a 23-in. liquid crystal monitor placed 60 cm from the eyes. The sentences were displayed horizontally and read from left to right. The number of unintentional re-readings of the same line was counted, and the disconjugacy at the median of the saccade between the end of a line and the next line was determined. RESULTS: The number of re-readings of the same line in patients with CI-type X(T) was 4.9 ± 2.3 times which was significantly higher than that in the controls at 0.2 ± 0.4 times (P < 0.001). The saccadic disconjugacy was significantly larger in patients with CI-type X(T) at -1.70° ± 0.72° than that in the controls at -0.40°± 0.30° (P < 0.001). The number of re-readings of the same line was significantly and positively correlated with the saccadic disconjugacy (R = 0.84, R (2) = 0.71, P < 0.01). CONCLUSIONS: The results of our study indicate that saccadic disconjugacy is associated with re-reading the same line in patients with CI-type X(T).
PURPOSE: To determine the relationship between re-reading the same line and saccadic disconjugacy in patients with convergence insufficiency-type intermittent exotropia [CI-type X(T)]. METHODS: Eight patients with CI-type X(T) and ten healthy orthophoric individuals were studied. Video-oculography was used to assess the eye movements during the reading of a Japanese novel displayed on a 23-in. liquid crystal monitor placed 60 cm from the eyes. The sentences were displayed horizontally and read from left to right. The number of unintentional re-readings of the same line was counted, and the disconjugacy at the median of the saccade between the end of a line and the next line was determined. RESULTS: The number of re-readings of the same line in patients with CI-type X(T) was 4.9 ± 2.3 times which was significantly higher than that in the controls at 0.2 ± 0.4 times (P < 0.001). The saccadic disconjugacy was significantly larger in patients with CI-type X(T) at -1.70° ± 0.72° than that in the controls at -0.40°± 0.30° (P < 0.001). The number of re-readings of the same line was significantly and positively correlated with the saccadic disconjugacy (R = 0.84, R (2) = 0.71, P < 0.01). CONCLUSIONS: The results of our study indicate that saccadic disconjugacy is associated with re-reading the same line in patients with CI-type X(T).
Authors: Eric J Borsting; Michael W Rouse; G Lynn Mitchell; Mitchell Scheiman; Susan A Cotter; Jeffrey Cooper; Marjean Taylor Kulp; Richard London Journal: Optom Vis Sci Date: 2003-12 Impact factor: 1.973