Grise Dulac A, Saad A, Abitbol O, Febbraro JL, Azan E, Moulin-Thyrode C, Gatinel D. Assessment of Corneal Biomechanical Properties in Normal Tension Glaucoma and Comparison With Open-angle Glaucoma, Ocular Hypertension, and Normal Eyes. Journal of Glaucoma, Sept 2011