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Abstract #46736 Published in IGR 13-3
Astigmatism and optical coherence tomography measurements
Hwang YH; Lee SM; Kim YY; Lee JY; Yoo CGraefe's Archive for Clinical and Experimental Ophthalmology 2011;
See also comment(s) by Tae-Woo Kim •
Background: To evaluate the effect of astigmatism change on measurement of retinal nerve fiber layer (RNFL) and macular thickness by Cirrus HD spectral-domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec, Dublin, CA, USA). Methods: A total of 30 right eyes from 30 healthy young subjects underwent RNFL and macular thickness measurements using Cirrus HD OCT. Measurements were performed at the baseline state and induced with-the-rule (WTR) and against-the-rule (ATR) astigmatism states by wearing toric soft contact lenses (+1.50 -3.25 diopter null 90(degrees) and +1.50 -3.25 diopter null 180(degrees) respectively). Dfferences in RNFL and macular thickness between the baseline state and induced astigmatism states were analyzed. Results: Wearing toric soft contact lenses induced a mean 2.92 diopter WTR and 3.18 diopter ATR astigmatism respectively. After signal strength change adjustment, RNFL thicknesses of average, superior quadrant, 12 and 6 o'clock hour sectors decreased after induction of a WTR astigmatism (mean difference range, 1.58 to 6.88 (mu)m); RNFL thicknesses of average, nasal, temporal quadrants, 2, 3, and 9 o'clock hour sectors decreased after induction of an ATR astigmatism (mean difference range, 0.75 to 5.11 (mu)m) (all P values <0.05). Macular thickness was not significantly affected by astigmatism changes (all P values (greater-than or equal to) 0.250). Conclusion: Although the amount of change was not substantial, RNFL thickness measured by Cirrus HD OCT was affected by astigmatism changes induced by contact lenses. It may be warranted to consider the effect of astigmatism on RNFL thickness measured by OCT in eyes with higher degrees of astigmatism.
Y.Y. Kim. Department of Ophthalmology, Korea University Guro Hospital, #97 Gurodonggil, Guro-gu, Seoul, 152-703, South Korea.
Classification:
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)
8.5 Other (Part of: 8 Refractive errors in relation to glaucoma)
2.2 Cornea (Part of: 2 Anatomical structures in glaucoma)
