Changes in corneal biomechanical properties after 24 hours of continuous intraocular pressure monitoring using a contact lens sensor

Abstract

Objective: This study was designed to assess changes in corneal topography and biomechanics after intraocular pressure (IOP) monitoring using the Triggerfish contact lens sensor (CLS).

Methods: For this prospective study, 30 eyes of 30 subjects: 14 healthy subjects (G1) and 6 glaucoma patients (G2), were recruited for 24 hours of continuous IOP monitoring using the CLS. The following measurements were taken before CLS fitting and after lens removal: maximum keratometry (Kmax), mean keratometry (MK), and corneal astigmatism (Cyl) measured through Pentacam corneal topography, and the corneal biomechanical variables corneal hysteresis (CH) and corneal resistance factor (CRF) measured with the Ocular Response Analyzer (ORA).

Results: Pentacam data revealed significant changes after CLS removal in Kmax (+3.14 ± 2.46 D, p = 0.002), MK (+0.52 ± 0.63 D, p = 0.02), and Cyl (+0.48 ± 0.53 D, p = 0.019) in G1; and Kmax (+1.38 ± 1.43 D, p = 0.002) in G2. The changes observed were more pronounced in G1 than in G2 but differences were not significant. The ORA results indicated higher CH (11.35 ± 2.42 vs 8.17 ± 2.09) and CRF (10.3 ± 2.03 vs 9.1 ± 1.81) before lens fitting in G1 than G2, while no significant changes were produced after CLS removal in either group.

Conclusions: The use of CLS for IOP monitoring over 24 hours caused topographic changes in both healthy subjects and glaucoma patients. No changes were produced in corneal biomechanics.