August 2019

ASCRS NEWS

Comparison of effect of eye rubbing in keratoconus and healthy eyes using Scheimpflug analysis and a dynamic bidirectional applanation device


María Henriquez, MD, PhD, Michelle Cerrate, MD, Martha Hadid, MD, Laura Cañola-Ramirez, MD, Farhad Hafezi, MD, PhD, Luis Izquierdo Jr., MD, PhD

J Cataract Refract Surg. 2019;45(8):1156–1162.

Purpose: To compare the effect of eye rubbing on Scheimpflug imaging parameters and corneal biomechanics in keratoconus (KC) and healthy eyes.
Setting: Oftalmosalud Instituto de Ojos, Lima, Peru.
Design: Prospective cohort study.
Methods: The study included 30 healthy eyes and 31 KC eyes that attended the Institution between January 2017 and July 2017. Eye rubbing was performed for 1 minute followed by a 5-second break, followed by further rubbing for 1 minute. Baseline tests were performed before rubbing; post-rubbing tests were performed immediately after (0 minutes), and then again at 7 and 14 minutes. Parameters related to anterior and posterior curvature and elevation, pachymetry, and corneal biomechanics obtained from tomography with a rotating Scheimpflug camera (Oculus Instruments) and the Ocular Response Analyzer were measured and compared between healthy and KC eyes.
Results: In the healthy group, the immediate mean change in steeper anterior keratometry, posterior astigmatism, anterior chamber volume, flattest posterior keratometry, and Goldman correlated intraocular pressure (IOPG) after eye rubbing was 0.07±0.15 diopters (D), –0.01±0.08 D, 0.03±7.06 mm3, –0.001±0.04 mm, and –1.21±1.99 mm Hg, whereas the mean change in the KC group was –0.03±0.32 D, 0.14±0.50 D, –5.09±8.45 mm3, 0.03±0.06 mm, and –1.61±1.41 mm Hg, respectively. There were statistically significant differences between pre- and post-eye rubbing values of posterior astigmatism, anterior chamber volume, and IOPG in the KC group (p=0.03, p=0.0003, and p=0.001, respectively) and not in the healthy group (p=0.65, p=0.85, and p=0.23, respectively).
Conclusions: Unlike the healthy eyes group, the keratoconus group experienced significant changes in anterior chamber volume, IOP, and corneal posterior astigmatism after eye rubbing.

Comparison of effect of eye rubbing in keratoconus and healthy eyes using Scheimpflug analysis and a dynamic bidirectional applanation device Comparison of effect of eye rubbing in keratoconus and healthy eyes using Scheimpflug analysis and a dynamic
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2019-07-29T15:03:41Z
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