Correlations among Corneal Biomechanical Parameters, Stiffness, and Thickness Measured Using Corvis ST and Pentacam in Patients with Ocular Hypertension

Abstract

Background. To preliminary explore the correlations among corneal biomechanical parameters, stiffness, and thickness in patients with ocular hypertension (OHT) before and after treatment with topical antiglaucoma medications. Methods. This was a retrospective study that included 35 eyes with newly diagnosed OHT. Axial length (AL), apical corneal thickness, and minimum corneal thickness were measured using Pentacam. The lengths, velocities, and times of the first and second corneal applanations (A1L, A1V, A1T, A2L, A2V, and A2T, respectively); the highest concavity radius; highest concavity peak distance (PDHC); highest concavity deformation amplitude (DAHC); highest concavity time (HCT); pachymetry (PACH); stress-strain index (SSI); stiffness parameter-A1 (SP-A1); deformation amplitude ratio (DA ratio); integrated radius (IR); Ambrosio’s relational thickness horizontal (ARTh); corneal biomechanical index; noncorrected intraocular pressure (IOPnct); and biomechanically corrected IOP (bIOP) values were measured using the corneal visualization Scheimpflug technology (Corvis ST/CST). Results. After 5 weeks of treatment, Goldman applanation tonometer-IOP, IOPnct, bIOP, PACH, A1T, A2V, SSI, SP-A1, and ARTh decreased, but A1V, A2T, PDHC, DAHC, DA ratio, and IR increased significantly (all p < 0.05 ). SP-A1 and A1T were positively associated with premedication IOP and IOP changes, whereas A1V, A2T, PDHC, and IR were negatively associated (all p < 0.05 ). DAHC and DA ratio had significantly negative correlations with IOP variations. PDHC was found to be positively correlated with AL ( p < 0.05 ). A positive relationship was noted between SP-A1 and HCT before medication ( p < 0.05 ). Conclusions. SP-A1 was significantly and consistently associated with IOP. HCT might be correlated with SP-A1. SP-A1 and CST parameters could serve as potential biomarkers for evaluating OHT treatment efficacy.

Comprehensive Assessment of Corvis ST Biomechanical Indices in Normal and Keratoconus Corneas with Reference to Corneal Enantiomorphism

“…A recent study has demonstrated a progressive decrease in the SSI with more advanced keratoconus stages, while the SSI was relatively independent of IOP and corneal central thickness but positively correlated with age [ 37 ]. A recent study showed that in eyes with ocular hypertension, the SSI decreases after initiation of treatment with topical antiglaucoma medications [ 38 ]. Whether this decrease is related to decreased intraocular pressure or drug-related ocular surface damage is still to be determined.…”

Quantitative changes in the corneal endothelium and central corneal thickness during anterior chamber inflammation: A systematic review and meta-analysis

“…This variation in CCT poses potential inaccuracies when measuring IOP using applanation tonometers during acute ACI episodes [39]. Utilizing noncontact measuring instruments could provide more accurate estimates of IOP in patients active and acute ACI [55]. However, such equipment has not been comprehensively tested in patients with ACI, and their use requires further investigation [56].…”