Anterior ocular surface sagittal height prediction

Stefan Bandlitz*, Matthias Lagodny, Corinna Kurz, James S. Wolffsohn

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Purpose: To investigate the validity of Placido-based corneal topography parameters to predict corneoscleral sagittal heights measured by Fourier-based profilometry at various diameters. Methods: Minimal (Min sag), maximal (Max sag) sagittal height, toricity (Max sag − Min sag) and axis of the flattest meridian (Min sag) of 36 subjects (mean age 25.4 SD ± 3.2 years; 21 female) were measured using the Eye Surface Profiler and analysed for diameters (chord length) of 8 to 16 mm (in 2-mm intervals). Furthermore, corneal central radii, corneal astigmatism, eccentricity and diameter were measured using the Keratograph 5 M. Results: Using multiple linear regression analysis, the best equation for predicting the sagittal heights for 8 mm (r 2 = 0.95), and 10 mm (r 2 = 0.93) diameters included corneal central radii and eccentricity. The best equation for predicting sagittal heights for 12 mm (r 2 = 0.86), 14 mm (r 2 = 0.78) and 16 mm (r 2 = 0.65) diameters included corneal central radii, eccentricity and corneal diameter. Corneal astigmatism was significantly correlated with sagittal height toricity for 8 and 10 mm diameters (r 2 = 0.50 and 0.29; p < 0.01), while no correlation was observed for 12, 14 and 16 mm diameters (p = 0.18 to p = 0.76). The axis of the flattest corneal meridian measured by Placido-based topography was significantly correlated with the axis of the flattest meridian measured by Fourier-based profilometry for 8, 10 and 12 mm diameters (r 2 = 0.17 to 0.44; p < 0.05), while there was no correlation for 14 and 16 mm diameters (p = 0.48 and p = 0.75). For a typical soft contact lens diameter of 14 mm, 78% of the variance could be determined with a corneal topographer and 68% with keratometry and corneal diameter measurement. Conclusions: The combination of corneal central radii, eccentricity and corneal diameter measured by Placido-based topography is a valid predictor of the corneoscleral sagittal height in healthy eyes. Scleral toricity and axis of the flattest meridian seem to be independent from Placido-based corneal parameters and requires additional measuring tools.

Original languageEnglish
JournalOphthalmic and Physiological Optics
Early online date15 Jun 2022
DOIs
Publication statusE-pub ahead of print - 15 Jun 2022

Keywords

  • Fourier-based profilometry
  • Placido-based topography
  • corneal diameter
  • corneal eccentricity
  • corneal radius
  • corneoscleral sagittal heights

Fingerprint

Dive into the research topics of 'Anterior ocular surface sagittal height prediction'. Together they form a unique fingerprint.

Cite this