Abstract
Abstract: :
Purpose: Stereopsis of early–onset esotropia (ET) is generally poor, but some children with treated ET could enjoy three dimensional (3–D) movies in amusement park. Because peripheral visual field is used when we see 3–D movies projected on a wide–angle screen, we developed a stereo–test using a large tangential screen and studied peripheral stereopsis for treated ET with poor macular stereopsis. Methods: Among consecutive ET patients who underwent strabismus surgery at Osaka University Hospital between 2000 and 2003, seventeen patients who showed poor macular stereopsis were studied. The age of examination ranged from 5 to 20 years (average 9.9 ± 4.1 years). Ten patients were infantile ET (infantile ET group) and 4 were partial accommodative ET, 3 were late–onset ET (Late ET group). Circular target with various disparities (0° to 3°) was projected on the screen using two projectors (3D–vision, Sanyo, Osaka) and patients were tested stereopsis wearing glasses with polarized filters. Target was projected with the angle 5°, 10°, 20° temporal from the fixation target. Size of a target ranged from a radius of 2.9° to 8.5°. We examined static peripheral stereopsis (SPS) by changing the position, disparity and size of the target. We also investigated motion peripheral stereopsis (MPS) using a circular target with a linear change of disparity from 0° to 1° (1300’’ per second). We also tested the macular stereopsis by Titmus fly test and the angle of suppression scotoma by 4 dot test. Results: All 17 patients failed Titmus fly test. SPS was identified in 7 patients (2: infantile ET group, 5: late ET group) and was failed in 10 patients (8: infantile ET group, 2: late ET group). Comparing the SPS (+) and SPS (–) group, there was no difference in the angle of strabismus and the age of examination. However, the onset age (months) of ET was significantly (p=0.045) older in SPS (+) group (14.3±12.7) compared with SPS (–) group (6.9±7.6). There was no difference in the detection rate between SPS and MPS. The success of SPS was not related to the angle of suppression scotoma. Conclusions: It was demonstrated that some patients with treated ET and without macular stereopsis showed peripheral stereopsis. The onset age of these patients were mostly late in infancy to early in childhood, suggesting that peripheral stereo test may be effective to detect potential stereopsis of ET patients with poor macular stereopsis.
Keywords: binocular vision/stereopsis • strabismus • visual development: infancy and childhood