Kazunori Hirasawa1, Shunsuke Nakakura2, Yoshitaka Nakao3, Yuri Fujino4, Masato Matsuura5, Hiroshi Murata4, Yoshiaki Kiuchi3, Ryo Asaoka6. 1. Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan; Moorfields Eye Hospital NHS Foundation Trust and University College London, Institute of Ophthalmology, London, United Kingdom; Department of Ophthalmology, School of Medicine, Kitasato University, Kanagawa, Japan. 2. Department of Ophthalmology, Saneikai Tsukazaki Hospital, Hyogo, Japan. 3. Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan. 4. Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan. 5. Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan; Department of Ophthalmology, Graduate School of Medical Sciences, Kitasato University, Kanagawa, Japan. 6. Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan. Electronic address: rasaoka-tky@umin.ac.jp.
Abstract
PURPOSE: To investigate the effects of cataract surgery on corneal biomechanics and intraocular pressure (IOP) measured with the updated Corvis ST tonometer (CST). DESIGN: Prospective, interventional case series study. METHODS: This study included 39 eyes of 39 cataract patients. CST measurements were performed at presurgery (Pre) as well as 1 week (1W), 1 month (1M), and 3 months (3M) postsurgery. The following CST parameters were recorded: deformation amplitude max (DA max), DA ratio max 1 mm and 2 mm, integrated radius, stiffness parameter at applanation 1 (SP A1), Ambrosio relational thickness to the horizontal profile (ARTh), Corvis biomechanical index (CBI), central corneal thickness (CCT), noncorrected intraocular pressure (IOPnct), and biomechanically corrected IOP (bIOP). IOP was also measured with Goldmann applanation tonometry and the noncontact tonometer CT-90A. All measurements were compared at each period using the linear mixed model, with and without adjustment for bIOP and CCT. RESULTS: All IOP measurements decreased over time (P < .01). CCT was increased at 1W and 3M (P < .01), whereas ARTh was decreased at 1W and 1M (P < .01), but returned to its Pre level at 3M. DA max and Integrated radius were increased at 3M (P < .01), whereas SP A1 was decreased at 3M (P < .01). CBI was increased at 1W (P < .01), but returned to its Pre level at 1M. CONCLUSIONS: IOP and Corneal biomechanical properties are changed after cataract surgery. In particular, SP A1 decreases while DA max and integrated radius increase, even at 3M, suggesting a less stiff cornea.
PURPOSE: To investigate the effects of cataract surgery on corneal biomechanics and intraocular pressure (IOP) measured with the updated Corvis ST tonometer (CST). DESIGN: Prospective, interventional case series study. METHODS: This study included 39 eyes of 39 cataractpatients. CST measurements were performed at presurgery (Pre) as well as 1 week (1W), 1 month (1M), and 3 months (3M) postsurgery. The following CST parameters were recorded: deformation amplitude max (DA max), DA ratio max 1 mm and 2 mm, integrated radius, stiffness parameter at applanation 1 (SP A1), Ambrosio relational thickness to the horizontal profile (ARTh), Corvis biomechanical index (CBI), central corneal thickness (CCT), noncorrected intraocular pressure (IOPnct), and biomechanically corrected IOP (bIOP). IOP was also measured with Goldmann applanation tonometry and the noncontact tonometer CT-90A. All measurements were compared at each period using the linear mixed model, with and without adjustment for bIOP and CCT. RESULTS: All IOP measurements decreased over time (P < .01). CCT was increased at 1W and 3M (P < .01), whereas ARTh was decreased at 1W and 1M (P < .01), but returned to its Pre level at 3M. DA max and Integrated radius were increased at 3M (P < .01), whereas SP A1 was decreased at 3M (P < .01). CBI was increased at 1W (P < .01), but returned to its Pre level at 1M. CONCLUSIONS: IOP and Corneal biomechanical properties are changed after cataract surgery. In particular, SP A1 decreases while DA max and integrated radius increase, even at 3M, suggesting a less stiff cornea.
Authors: Majid Moshirfar; Mahsaw N Motlagh; Michael S Murri; Hamed Momeni-Moghaddam; Yasmyne C Ronquillo; Phillip C Hoopes Journal: Med Hypothesis Discov Innov Ophthalmol Date: 2019