Corneal biomechanics: A diagnostic tool for differentiating high astigmatism and mild keratoconus
Background: High astigmatism (HA) can be misinterpreted as keratoconus (KCN), is highly prone to developing KCN and is normally reconfirmed using corneal topography. Aim: To determine the diagnostic value of corneal biomechanical parameters in distinguishing HA and normal eyes from mild KCN. Setti...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
AOSIS
2025-01-01
|
| Series: | African Vision and Eye Health |
| Subjects: | |
| Online Access: | https://avehjournal.org/index.php/aveh/article/view/953 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Background: High astigmatism (HA) can be misinterpreted as keratoconus (KCN), is highly prone to developing KCN and is normally reconfirmed using corneal topography.
Aim: To determine the diagnostic value of corneal biomechanical parameters in distinguishing HA and normal eyes from mild KCN.
Setting: This is a comparative retrospective study.
Methods: This study assessed 55 eyes with mild KCN (stages I and II), 56 eyes with HA ( 2.0 DC) without KCN and 55 normal healthy eyes. Corneal biomechanical and tomography parameters were measured using the Corvis ST and Pentacam HR (Oculus Optikgeräte GmbH, Germany). Keratoconus was diagnosed through slit lamp examination and abnormal corneal tomography patterns. The Kruskal–Wallis test evaluated each parameter’s distinguishing capability, and the receiver operating characteristic curve (ROC) analyzed the ability to differentiate high astigmatism and normal eyes from mild KCN.
Results: The Corvis biomechanical index (CBI) between HA and mild KCN reflected a lower area under the curve (AUC) of 0.859, with a sensitivity of 92.7% and specificity of 65.4%, than CBI between normal and mild KCN, with an AUC of 0.896. The AUC for the Belin / Ambrósio enhanced ectasia deviation index (BAD-D) was 0.993, while the tomographical and biomechanical index (TBI) achieved an AUC of 0.99.
Conclusion: Scheimpflug-derived biomechanical parameters effectively differentiated suspected HA and normal corneas from mild KCN corneas, indicating that corneal stiffness decreases at the early KCN stage.
Contribution: Oculus Corvis ST effectively screens for ectasia risk, enabling early detection of KCN in individuals with high astigmatism and asymmetric curvature. |
|---|---|
| ISSN: | 2413-3183 2410-1516 |