To determine whether corneal biomechanical properties and intraocular pressure (IOP) are affected by eye rubbing and breath holding.
Corneal hysteresis, corneal resistance factor, corneal compensated IOP (IOPcc), and Goldmann equivalent IOP (IOPg) were measured on both eyes of 40 subjects. Measurements were taken at baseline before eye rubbing (ER0) and before breath holding (BH0), immediately after 2 episodes of eye rubbing (ER1 and ER2), and during 2 episodes of breath holding (BH1 and BH2).
Corneal hysteresis, corneal resistance factor, and IOPg were significantly lower after ER1 compared with ER0 and were significantly lower after ER2 compared with ER1. In contrast, IOPcc did not decrease significantly. There were no significant differences among BH0, BH1, and BH2 in any of the 4 outcomes.
Eye rubbing should be avoided before measurements of corneal biomechanical properties and IOPg. In contrast, breath holding during measurements is not likely to cause a significant change in IOPg and IOPcc or corneal biomechanical properties.
From the *Department of Ophthalmology, Taoyuan Veterans Hospital, Taoyuan, Taiwan; †School of Medicine, National Yang-Ming University, Taipei, Taiwan; ‡Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan; and §Clinical Research Center and School of Optometry, University of California, Berkeley, CA.
Received for publication April 12, 2010; revision received July 26, 2010; accepted August 11, 2010.
Supported, in part, by grant from the Taoyuan Veterans Hospital, Taiwan (960004643), and by an unrestricted research fund for clinical research fellows from the Clinical Research Center, University of California, Berkeley.
Parts of this research were presented, in abstract form, at the 2009 ARVO Annual Meeting, Fort Lauderdale, FL.
The authors report no commercial or conflicts of interest.
Reprints: Meng C. Lin, Clinical Research Center, School of Optometry, University of California, Berkeley, CA 94720-2020 (e-mail: email@example.com).