Abstract
Abstract: :
Purpose: To verify the changes of mesopic and photopic contrast sensitivity function of sound eye whose visual acuity was kept the same after occlusion therapy in amblyopic children. Methods: Fourteen sound eyes of amblyopic children (Mean;7.67 years; S.D.,1.50 years) which kept their visual acuity the same after the occlusion therapy were tested. The children had 6 hours of part-time patch therapy for 3 months prior to this examination. Among 14 amblyopic children, 8 were anisometric and 6 were strabismic amblyopes. Using ACV, which measures the minimal contrast level from low to high spatial frequencies, the contrast sensitivity of sound eye was measured, under both photopic and mesopic condition, before and after 3 months of occlusion therapy. Results: All amblyopic children had no change in visual acuity of their sound eyes after 3 months of occlusion. Comparing the contrast sensitivity of sound eye after the occlusion therapy to that before the occlusion, there was no statistical difference in photopic condition. When it comes to mesopic condition, the contrast sensitivity decreased after the occlusion therapy in intermediate spastial frequency level(3-13 c.p.d of Landolt ring, p = 0.028, Wilcoxon Signed Ranks Test). Conclusion: There was a decrease in mesopic contrast sensitivity in the sound eye even though the visual acuity was not change after the occlusion therapy. It may indicate that mesopic contrast sensitivity can be considered as early sign of a hidden occlusion amblyopia. The occlusion did not cause any statistically significant decrease in photopic contrast sensitivity, but mesopic contrast sensitivity of them decreased markedly, a early sign of beginning occlusion amblyopia. The amblyopic eye may influence contrast sensitivity of the dominant eye through interocular interactions during occlusion. This process may serve to minimize contrast sensitivity differences between the eyes and maximize binocular vision.
Keywords: 368 contrast sensitivity • 313 amblyopia