Repeatability Of Anterior Segment Optical Coherence Tomography In Patients With Keratoconus
Published 2025 - 43rd Congress of the ESCRS
Reference: PP02.01 | Type: Poster | DOI: 10.82333/8z8p-0p76
Authors: Tadas Naujokaitis* 1 , Ramin Khoramnia 2 , Maximilian Friedrich 1 , Hyeck-Soo Son 1 , Gerd U. Auffarth 1 , Victor A. Augustin 1
1Department of Ophthalmology,University of Heidelberg,Heidelberg,Germany, 2Department of Ophthalmology,University of Heidelberg,Heidelberg,Germany;Department of Ophthalmology,Carl Gustav Carus Dresden University Hospital,Dresden,Germany
Purpose
To assess the repeatability of corneal parameters measured by optical coherence tomography in patients with keratoconus compared to healthy subjects.
Setting
International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany
Methods
The cross-sectional study included 269 eyes from a total of 137 subjects: 188 eyes from 96 keratoconus patients and 81 eyes from 41 healthy subjects. Using anterior segment optical coherence tomography (Anterion; Heidelberg Engineering), 3 measurements per eye were performed and the parameters of the anterior and posterior surface of the cornea, pachymetry, and epithelial and stromal parameters were evaluated. To assess repeatability, the intraindividual standard deviations of the three measurements were calculated and compared between the groups using the t-test. Mean values and standard deviations are provided. The differences between the maximum and minimum measured values (max-min) are presented as measurement fluctuations.
Results
The repeatability of mean anterior keratometry was 0.08±0.07D in keratoconus eyes and 0.05±0.04D in healthy eyes (p<0.001), of maximum keratometry (Kmax) 0.15±0.13D and 0.09±0.07D (p<0.001), of anterior astigmatism 0.09±0.07D and 0.07±0.05D (p=0.004), of posterior astigmatism 0.01±0.02D and 0.01±0.00D (p=0.31), of maximum posterior elevation of the 0.7±0.8µm and 0.5±0.4µm (p=0.04), of minimum pachymetry 0.5±0.5µm and 0.4±0.3µm (p=0.10), of mean epithelial thickness 0.4±0.5µm and 0.4±0.4µm (p=0.53), and of mean stromal thickness 0.6±0.9µm and 0.6±0.8µm (p=0.55). The measurement fluctuations (max-min) of Kmax were 0.2±0.2D in eyes with Kmax <50D (n=171), 0.4±0.3D with Kmax between 50D and 60D (n=86) and 0.6±0.4D with Kmax >60D (n=12).
Conclusions
Good repeatability of corneal parameters was observed in both keratoconus patients and healthy subjects. The repeatability of anterior curvature parameters was lower in keratoconus patients compared to healthy subjects. The measurement fluctuations of the Kmax value increased with increasing parameter value.