Corneal biomechanics and biomechanically corrected intraocular pressure in primary open-angle glaucoma, ocular hypertension and controls

Abstract

AimsTo compare the biomechanically corrected intraocular pressure (IOP) estimate (bIOP) provided by the Corvis-ST with Goldmann applanation tonometry (GAT-IOP) in patients with high-tension and normal-tension primary open-angle glaucoma (POAG; HTG and NTG), ocular hypertension (OHT) and controls. Moreover, we compared dynamic corneal response parameters (DCRs) of the Corvis-ST in POAG, OHT and controls, evaluated the correlation between global visual field parameters mean deviation and pattern SD (MD and PSD) and DCRs in the POAG group.Methods156 eyes of 156 patients were included in this prospective, single-centre, observational study, namely 41 HTG and 33 NTG, 45 OHT cases and 37 controls. Central corneal thickness (CCT), GAT-IOP and bIOP were measured, GAT-IOP was also adjusted for CCT (GATAdj). DCRs provided by Corvis-ST were evaluated, MD and PSD were recorded by 24–2 full-threshold visual field. To evaluate the difference in DCRs between OHT, HTG and NTG, a general linear model was used with sex, medications and group as fixed factors and bIOP and age as covariates.ResultsThere was a significant difference between GAT-IOP, GATAdj and bIOP in NTG and HTG, OHT and controls. NTG corneas were significantly softer and more deformable compared with controls, OHT and HTG as demonstrated by significantly lower values of stiffness parameters A1 and highest concavity and higher values of inverse concave radius (all p<0.05). There was a significant correlation (p<0.05) between MD, PSD and many DCRs with POAG patients with softer or more compliant corneas more likely to show visual field defects.ConclusionsCorneal biomechanics might be a significant confounding factor for IOP measurement that should be considered in clinical decision-making. The abnormality of corneal biomechanics in NTG and the significant correlation with visual field parameters might suggest a new risk factor for the development or progression of NTG.

Dynamic Scheimpflug Ocular Biomechanical Parameters in Untreated Primary Open Angle Glaucoma Eyes

“…16 Several previous studies showed differences in the dynamic Scheimpflug biomechanical parameters between healthy and glaucoma eyes. [17][18][19][20][21] However, these results are conflicting with respect to the biomechanical changes associated with glaucoma. [17][18][19][20][21] Part of the discrepancy may be explained by the confounding effects of baseline factors such as age, IOP, type of disease, and axial length.…”

“…[17][18][19][20][21] However, these results are conflicting with respect to the biomechanical changes associated with glaucoma. [17][18][19][20][21] Part of the discrepancy may be explained by the confounding effects of baseline factors such as age, IOP, type of disease, and axial length. 16,22 For example, most prior studies included glaucoma patients with high baseline 18,19 or relatively high treated IOP.…”

Künstliche Intelligenz zur Entwicklung von Screening-Parametern im Bereich der kornealen Biomechanik

“…Bereits seit Längerem ist bekannt, dass die Biomechanik der Augenhülle bei Offenwinkelglaukomen verändert ist [18]. Auch mit dem Corvis ST konnten in verschiedenen Arbeiten signifikante Unterschiede von Biomechanikparametern zwischen gesunden und pathologischen Patientenkollektiven festgestellt werden [19]. Wieder stellte sich die Frage, inwiefern Machine-Learning-Algorithmen bei der Entwicklung eines Gesamtparameters behilflich sein könnten.…”

Comparison of intraocular pressure measured by ocular response analyzer and Goldmann applanation tonometer after corneal refractive surgery: a systematic review and meta-analysis

“…And the biomechanical corrected IOP (bIOP) [31] is purported to be less dependent on biomechanical properties. At present, there are some researches to further explore and verify the IOP measurement of bIOP in healthy people [32] , glaucoma [33] and even keratoconus patients [32] . In addition, it has been proposed [34] that bIOP is able to reduce the known correlation between CCT and IOP readings before and after refractive surgery, such as LASIK and small-incision lenticule extraction (SMILE) [34] .…”