Comparison Of Corneal Biomechanics In Open-Angle Glaucoma Patients Between Normal And High Pressure Glaucoma.
Published 2025 - 43rd Congress of the ESCRS
Reference: PO653 | Type: Free paper | DOI: 10.82333/hv60-hn89
Authors: Dimitrios Kyroudis* 1 , Christoph Tappeiner 2 , David Goldblum 3
1Refractive surgery,Pallas Kliniken AG,Bern,Switzerland, 2Cornea & Uveitis,Pallas Kliniken AG,Bern,Switzerland;Ophthalmology,University Duisburg-Essen,Essen,Germany;Ophthalmology,University of Bern,Bern,Switzerland, 3Cornea & Ocular surface,Pallas Kliniken AG,Bern,Switzerland;Ophthalmology,University of Basel,Basel,Switzerland
Purpose
Normal-pressure glaucoma is a form of primary open angle glaucoma (POAG) with normal IOP, resulting in axonal damage. The cornea and lamina cribrosa are continuous collagen sheaths made up of similar extracellular matrix components. Consequently, the biomechanical properties of the cornea may represent those of the lamina Cribrosa tissue.
We aim in this study to show the differences in corneas of POAG and Normal tension glaucoma (NTG)
Setting
We carried out a comparative study at mohammed VI University Hospital over a 4-month period Patients were selected on the basis of a specialized glaucoma consultation
All patients underwent a complete ophthalmological examination with 2 visual fields and a papillary OCT All patients with secondary glaucoma were not included in our study
Methods
This study compared the biomechanical characteristics of the 2 groups using CorVis-ST (Corneal Visualization Scheimpflug Technology).
The parameters assessed by CorVis-ST are as follows:
-Intraocular pressure adapted to corneal biomechanics bPIO
-Parameters exploring corneal deformability: Inverse Concave Radius (ICR) and its integral (Intergral Radius IR), Deformation Amplitude Ratio (DA R) , and Stiffness Parameter at first applanation (SP-A1)
-Biomechanical glaucoma factor BGF
Results
We counted a total of 35 eyes, 19 with high-pressure glaucoma and 16 with normal pressure. The median age of our participants was 68 years [62-71] , with a male/female sex ratio of 0.63. Mean ocular tonus per applanation in the 2 groups was 18.96 mmHg, with a significant difference between the 2 groups p=0.013, higher in group 1 with a median value of 15.50 versus 13.50 in group 2, and mean corneal pacchymetry 518 μm finer in glaucoma patients at normal pressure (510 μm, p=0.025),
Comparative analysis between the 2 groups showed:
BGF: 0.35 [0.29-0.45] VS 0.745 [0.60-0.85], p<0.001
DAR: 4.40 [4.06-4.55] VS 4.96 [4.38-5.32], p=0.001
SPA1: 118.80 [109.10-124.60] VS 100.70 [98.20-116.47], p=0.005 Reflecting a more deformable cornea in group 2.
Conclusions
These results affirm that the cornea of Normal tension glaucoma were more deformable than that of patients with hypertension glaucoma, and therefore more sensitive to the same IOP stress conditions, resulting in a lower target IOP, adapted to corneal biomechanics