Repeatability of Corneal Astigmatism and Equivalent Power with the MS-39 Tomographer Derived from Model Surface Fitting in a Cataractous Population
Abstract
Highlights
- Modern high-resolution anterior segment tomographers are capable of extracting surface height data from the corneal front and back surfaces and from the epithelium–stroma interface.
- The higher refractive index of the corneal epithelium suggests that the cornea should be considered as a dual-layer structure to account for potential inhomogeneity in the epithelial thickness.
- Model surfaces, such as floating best-fit spheres or conoids, could be fitted to the height map data within a specific region of interest to determine relevant surface characteristics such as curvatures, asphericities, and apex positions.
- Based on a dataset with bilateral repeat measurements in a cataractous population, we were able to confirm that the extracted surface characteristics seem to be very robust. However, surface asphericity should be extracted from a larger region of interest to ensure more robust data.
Abstract
1. Introduction
- to extract height map data for the epithelium, stroma, and endothelium from a high-resolution anterior segment optical coherence tomographer,
- to develop a strategy for fitting floating spherocylinders, cylindrical conoids, and biconic surfaces to these height map data within a specific region of interest, and to extract the apical radii R1 and R2 together with the axis A1 and optionally the asphericity Q or Q1 and Q2,
- and using a large dataset of repeat measurements in a study population measured prior to cataract surgery to investigate the robustness of these parameters in order to quantify the repeatability of these characteristic metrics.
2. Materials and Methods
2.1. Dataset for Our Evaluation
2.2. Data Pre-Processing in Matlab
2.3. Data Processing in Matlab and Statistics
3. Results
4. Discussion
5. Conclusions
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Kose, B. Agreement between swept-source optical biometry and Scheimpflug-based topography measurements of posterior corneal curvature. J. Cataract Refract. Surg. 2022, 48, 185–189. [Google Scholar] [CrossRef] [PubMed]
- Langenbucher, A.; Taroni, L.; Coutinho, C.P.; Cayless, A.; Szentmáry, N.; Hoffmann, P.; Wendelstein, J.; Savini, G. Evaluating keratometry and corneal astigmatism data from biometers and anterior segment tomographers and mapping it to reconstructed corneal astigmatism. Clin. Exp. Ophthalmol. 2024, 52, 627–638. [Google Scholar] [CrossRef] [PubMed]
- Schiano-Lomoriello, D.; Hoffer, K.J.; Abicca, I.; Savini, G. Repeatability of automated measurements by a new anterior segment optical coherence tomographer and biometer and agreement with standard devices. Sci. Rep. 2021, 11, 983. [Google Scholar] [CrossRef] [PubMed]
- Zhang, T.; Zhou, Y.; Young, C.A.; Chen, A.; Jin, G.; Zheng, D. Comparison of a new swept-source anterior segment optical coherence tomography and a Scheimpflug camera for measurement of corneal curvature. Cornea 2020, 39, 818–822. [Google Scholar] [CrossRef]
- Asawaworarit, R.; Satitpitakul, V.; Taweekitikul, P.; Pongpirul, K. Agreement of total corneal power between 2 swept-source optical coherence tomography and Scheimpflug tomography in normal and keratoconic patients. PLoS ONE 2022, 17, e0268856. [Google Scholar] [CrossRef]
- Biswas, S.; Biswas, P. Agreement and repeatability of corneal thickness and radius among three different corneal measurement devices. Optom. Vis. Sci. 2021, 98, 1196–1202. [Google Scholar] [CrossRef]
- Cheng, S.; Zhang, J.; Zhou, K.; Li, T.; Lin, J.; Yu, A.Y. Repeatability and agreement of two swept-source optical coherence tomographers and Scheimpflug imaging for measurements of corneal curvature. BMC Ophthalmol. 2024, 24, 439. [Google Scholar] [CrossRef]
- Cheng, S.M.; Zhang, J.S.; Li, T.T.; Wu, Z.T.; Wang, P.; Yu, A.Y. Repeatability and agreement of two swept-source optical coherence tomographers for anterior segment parameter measurements. J. Glaucoma 2022, 31, 602–608. [Google Scholar] [CrossRef]
- Cheng, S.M.; Zhang, J.S.; Shao, X.; Wu, Z.T.; Li, T.T.; Wang, P.; Lin, J.H.; Yu, A.Y. Repeatability of a new swept-source optical coherence tomographer and agreement with other three optical biometers. Graefe’s Arch. Clin. Exp. Ophthalmol. 2022, 260, 2271–2281. [Google Scholar] [CrossRef]
- Dembski, M.; Nowińska, A.; Ulfik-Dembska, K.; Wylęgała, E. Swept source optical coherence tomography analysis of selected eye’s anterior segment parameters. J. Clin. Med. 2021, 10, 1094. [Google Scholar] [CrossRef]
- Jin, G.M.; Xiao, B.; Zhou, Y.J.; Wang, Y.Y.; Li, X.P.; Zheng, D.Y. Agreement of corneal curvature and central corneal thickness obtained from a swept-source OCT and Pentacam in ectopia lentis patients. Int. J. Ophthalmol. 2020, 13, 1244–1249. [Google Scholar] [CrossRef]
- Kiraly, L.; Stange, J.; Kunert, K.S.; Sel, S. Repeatability and agreement of central corneal thickness and keratometry measurements between four different devices. J. Ophthalmol. 2017, 2017, 6181405. [Google Scholar] [CrossRef] [PubMed]
- Langenbucher, A.; Szentmáry, N.; Cayless, A.; Schartmüller, D.; Lisy, M.; Menapace, R.; Wendelstein, J.; Leydolt, C. Repeatability of corneal measurements from the Casia2 anterior segment tomographer in a cataractous population. PLoS ONE 2025, 20, e0328894. [Google Scholar] [CrossRef]
- Li, X.; Zhou, Y.; Young, C.A.; Chen, A.; Jin, G.; Zheng, D. Comparison of a new anterior segment optical coherence tomography and Oculus Pentacam for measurement of anterior chamber depth and corneal thickness. Ann. Transl. Med. 2020, 8, 857. [Google Scholar] [CrossRef] [PubMed]
- Savini, G.; Schiano-Lomoriello, D.; Hoffer, K.J. Repeatability of automatic measurements by a new anterior segment optical coherence tomographer combined with Placido topography and agreement with 2 Scheimpflug cameras. J. Cataract Refract. Surg. 2018, 44, 471–478. [Google Scholar] [CrossRef]
- Schröder, S.; Eppig, T.; Langenbucher, A. A Concept for the analysis of repeatability and precision of corneal shape measurements. Z. Med. Phys. 2016, 26, 150–158. [Google Scholar] [CrossRef]
- Feng, Y.; Reinstein, D.Z.; Nitter, T.; Archer, T.J.; McAlinden, C.; Bertelsen, G.; Stojanovic, A. Epithelial thickness mapping in keratoconic corneas: Repeatability and agreement between CSO MS-39, Heidelberg Anterion, and Optovue Avanti OCT devices. J. Refract. Surg. 2023, 39, 474–480, Erratum in J. Refract. Surg. 2024, 40, e62. [Google Scholar] [CrossRef]
- Farrell, P.J.; Salibian-Barrera, M.; Naczk, K. On tests for multivariate normality and associated simulation studies. J. Stat. Comput. Simul. 2007, 77, 1065–1080. [Google Scholar] [CrossRef]
- Nabil, H. Mustafa, Saurabh Ray. An optimal extension of the centerpoint theorem. Comput. Geom. 2009, 42, 505–510. [Google Scholar] [CrossRef]
- Small, C.G. A Survey of multidimensional medians. Int. Stat. Rev. 1990, 58, 263–277. [Google Scholar] [CrossRef]
- Small, C.G. Measures of centrality for multivariate and directional distributions. Can. J. Stat./Rev. Can. Stat. 1987, 5, 31–39. [Google Scholar] [CrossRef]
- Welk, M.; Breuß, M. The Convex-Hull-Stripping median approximates affine curvature motion. In Scale Space and Variational Methods in Computer Vision. Lecture Notes in Computer Science; Lellmann, J., Burger, M., Modersitzki, J., Eds.; Springer: Cham, Germany, 2025; Volume 11603, pp. 198–210. [Google Scholar] [CrossRef]
- Langenbucher, A.; Szentmáry, N.; Cayless, A.; Bolz, M.; Hoffmann, P.; Wendelstein, J. Prediction of spectacle refraction uncertainties with discrete IOL power steps and manufacturing tolerances according to ISO using a Monte Carlo model. Br. J. Ophthalmol. 2024, 108, 793–800. [Google Scholar] [CrossRef]
- Langenbucher, A.; Szentmáry, N.; Cayless, A.; Cooke, D.; Hoffmann, P.; Wendelstein, J. Prediction of refraction error after toric lens implantation with biometric input data uncertainties and power labelling tolerances. Clin. Exp. Ophthalmol. 2025, 53, 26–38, Response in Clin. Exp. Ophthalmol. 2025, 53, 219–220. [Google Scholar] [CrossRef]







| Radii(R1, R2) [mm], Asphericity (Q, Q1, Q2) [1] | R1 | R2 | R1 | R2 | Q | R1 | R2 | Q1 | Q2 | |
|---|---|---|---|---|---|---|---|---|---|---|
| ROI 3 mm | SphCyl3 | CylConoid3 | Biconic3 | |||||||
| Epithelium | Mean | 7.8013 | 7.5671 | 7.7882 | 7.5538 | −0.1685 | 7.7950 | 7.5493 | −0.1526 | −0.2290 |
| SD | 0.3404 | 0.3286 | 0.3466 | 0.3358 | 0.2623 | 0.3475 | 0.3358 | 0.2759 | 0.3110 | |
| Median | 7.7778 | 7.5754 | 7.7581 | 7.5529 | −0.1896 | 7.7490 | 7.5507 | −0.1772 | −0.2320 | |
| 2.5% quantile | 7.1810 | 6.9388 | 7.1815 | 6.9222 | −0.7001 | 7.1832 | 6.9144 | −0.7342 | −0.8694 | |
| 97.5% quantile | 8.5964 | 8.3171 | 8.6126 | 8.3466 | 0.4119 | 8.6426 | 8.3370 | 0.4444 | 0.4510 | |
| Stroma | Mean | 7.7704 | 7.4730 | 7.7056 | 7.4057 | −0.3837 | 7.7463 | 7.3846 | −0.3335 | −0.4222 |
| SD | 0.3845 | 0.3658 | 0.4002 | 0.3915 | 0.3210 | 0.3932 | 0.3891 | 0.3104 | 0.3066 | |
| Median | 7.7280 | 7.4601 | 7.6685 | 7.3894 | −0.3640 | 7.7081 | 7.3675 | −0.2926 | −0.3674 | |
| 2.5% quantile | 7.1605 | 6.7021 | 6.9875 | 6.5276 | −1.1442 | 7.0316 | 6.5862 | −1.0877 | −1.0880 | |
| 97.5% quantile | 8.7329 | 8.2779 | 8.6579 | 0.2534 | 0.3771 | 8.7334 | 8.2202 | 0.3268 | 0.3751 | |
| Endothelium | Mean | 6.6194 | 6.2590 | 6.5972 | 6.2357 | −0.2886 | 6.6008 | 6.2269 | −0.2141 | −0.2904 |
| SD | 0.3367 | 0.3352 | 0.3515 | 0.3534 | 0.4297 | 0.3570 | 0.3500 | 0.4144 | 0.3612 | |
| Median | 6.5954 | 0.2519 | 6.5739 | 6.2389 | −0.2414 | 6.5912 | 6.2347 | −0.2448 | −0.2971 | |
| 2.5% quantile | 6.0315 | 5.6346 | 5.9935 | 5.4012 | −1.1163 | 5.9880 | 5.3974 | −1.0655 | −1.0519 | |
| 97.5% quantile | 7.4164 | 6.9361 | 7.4166 | 6.9009 | 0.5272 | 7.4329 | 6.8924 | 0.5338 | 0.3849 | |
| ROI 6 mm | SphCyl6 | CylConoid6 | Biconic6 | |||||||
| Epithelium | Mean | 7.8261 | 7.6124 | 7.7809 | 7.5664 | −0.1866 | 7.7895 | 7.5586 | −0.1614 | −0.2137 |
| SD | 0.3232 | 0.3109 | 0.3441 | 0.3364 | 0.1854 | 0.3500 | 0.3354 | 0.2025 | 0.2069 | |
| Median | 7.8193 | 7.6253 | 7.7593 | 7.5606 | −0.1948 | 7.7720 | 7.5597 | −0.1796 | −0.2043 | |
| 2.5% quantile | 7.2420 | 7.0143 | 7.1393 | 6.9470 | −0.5222 | 7.1448 | 6.9246 | −0.4661 | −0.7409 | |
| 97.5% quantile | 8.4622 | 0.2677 | 8.6511 | 8.4193 | 0.2153 | 8.6390 | 8.3981 | 0.3803 | 0.1831 | |
| Stroma | Mean | 7.7598 | 7.5330 | 7.6969 | 7.4689 | −0.2466 | 7.7217 | 7.4455 | −0.1568 | −0.3331 |
| SD | 0.3512 | 0.3219 | 0.3984 | 0.3743 | 0.2528 | 0.3972 | 0.3813 | 0.2378 | 0.2563 | |
| Median | 7.7473 | 7.5436 | 7.6746 | 7.4416 | −0.2312 | 7.7019 | 7.4184 | −0.1440 | −0.3181 | |
| 2.5% quantile | 7.1196 | 6.8844 | 7.0177 | 6.8457 | −0.8834 | 7.0455 | 6.7393 | −0.6605 | −0.8961 | |
| 97.5% quantile | 8.5927 | 8.2746 | 8.6746 | 8.4288 | 0.3078 | 8.7061 | 8.4090 | 0.3573 | 0.1217 | |
| Endothelium | Mean | 6.6557 | 6.3320 | 6.5426 | 6.2133 | −0.3187 | 6.5416 | 6.2100 | −0.2962 | −0.3433 |
| SD | 0.2889 | 0.2800 | 0.3226 | 0.3374 | 0.2174 | 0.3258 | 0.3426 | 0.2603 | 0.2353 | |
| Median | 6.6369 | 6.3357 | 6.5227 | 6.1929 | −0.3281 | 6.5238 | 6.1929 | −0.3005 | −0.3335 | |
| 2.5% quantile | 6.1629 | 5.8419 | 6.9037 | 5.5799 | −0.7444 | 5.9392 | 5.5858 | −0.9739 | −0.8602 | |
| 97.5% quantile | 7.3289 | 6.9063 | 7.2769 | 6.8808 | 0.1680 | 7.2761 | 6.9015 | 0.2548 | 0.1078 | |
| Radii(R1, R2) [mm], Asphericity (Q, Q1, Q2) [1] | R1 | R2 | R1 | R2 | Q | R1 | Q1 | R2 | Q2 | |
|---|---|---|---|---|---|---|---|---|---|---|
| ROI 3 mm | SphCyl3 | CylConoid3 | Biconic3 | |||||||
| Epithelium | SD | 0.0112 | 0.0099 | 0.0167 | 0.0164 | 0.0555 | 0.0187 | 0.0174 | 0.0586 | 0.0637 |
| Median | 0.0000 | 0.0002 | 0.0001 | 0.0000 | 0.0010 | −0.0001 | −0.0001 | 0.0000 | 0.0000 | |
| 2.5% quantile | −0.0219 | −0.0215 | −0.0347 | −0.0360 | −0.1131 | −0.0412 | −0.0377 | −0.1123 | −0.1139 | |
| 97.5% quantile | 0.0216 | 0.0215 | 0.0320 | 0.0342 | 0.1117 | 0.0379 | 0.0337 | 0.1119 | 0.1135 | |
| Stroma | SD | 0.0726 | 0.0348 | 0.0714 | 0.0467 | 0.0508 | 0.0754 | 0.0522 | 0.0544 | 0.0504 |
| Median | −0.0003 | 0.0001 | 0.0000 | 0.0010 | 0.0000 | 0.0003 | 0.0000 | 0.0000 | 0.0000 | |
| 2.5% quantile | −0.0396 | −0.0429 | −0.0512 | −0.0732 | −0.1117 | −0.0786 | −0.0773 | −0.1132 | −0.1108 | |
| 97.5% quantile | 0.0444 | 0.0371 | 0.0560 | 0.0604 | 0.1124 | 0.0749 | 0.0784 | 0.1139 | 0.1102 | |
| Endothelium | SD | 0.0875 | 0.0304 | 0.0892 | 0.0336 | 0.0652 | 0.0890 | 0.0377 | 0.0659 | 0.0629 |
| Median | −0.0007 | 0.0005 | −0.0005 | 0.0008 | 0.0000 | −0.0008 | 0.0000 | 0.0000 | 0.0017 | |
| 2.5% quantile | −0.0295 | −0.231 | −0.0356 | −0.0359 | −0.1135 | −0.0510 | −0.0506 | −0.1139 | −0.1142 | |
| 97.5% quantile | 0.0230 | 0.0248 | 0.0335 | 0.0393 | 0.1145 | 0.0568 | 0.0556 | 0.1149 | 0.1141 | |
| ROI 6 mm | SphCyl6 | CylConoid6 | Biconic6 | |||||||
| Epithelium | SD | 0.0061 | 0.0067 | 0.0094 | 0.0093 | 0.0228 | 0.0108 | 0.0106 | 0.0281 | 0.0312 |
| Median | −0.0001 | 0.0000 | 0.0000 | 0.0001 | −0.0002 | −0.0001 | −0.0001 | 0.0001 | −0.0005 | |
| 2.5% quantile | −0.0133 | −0.0131 | −0.0198 | −0.0191 | −0.0440 | −0.0218 | −0.0221 | −0.0592 | −0.0702 | |
| 97.5% quantile | 0.0143 | 0.0134 | 0.0186 | 0.0214 | 0.0456 | 0.0215 | 0.0229 | 0.0589 | 0.0687 | |
| Stroma | SD | 0.0204 | 0.0251 | 0.0261 | 0.0233 | 0.0350 | 0.0244 | 0.0250 | 0.0507 | 0.0493 |
| Median | −0.0002 | 0.0002 | −0.0005 | −0.0002 | −0.0007 | −0.0002 | 0.0002 | −0.0001 | 0.0007 | |
| 2.5% quantile | −0.0202 | −0.0162 | −0.0281 | −0.0347 | −0.0753 | −0.0426 | −0.0397 | −0.0961 | −0.1054 | |
| 97.5% quantile | 0.0204 | 0.0211 | 0.0329 | 0.0313 | 0.0742 | 0.0437 | 0.0372 | 0.1091 | 0.1021 | |
| Endothelium | SD | 0.0139 | 0.0251 | 0.0257 | 0.0216 | 0.0238 | 0.0302 | 0.0226 | 0.0378 | 0.0348 |
| Median | 0.0001 | 0.0002 | −0.0004 | −0.0002 | 0.0000 | −0.0003 | 0.0000 | −0.0001 | −0.0003 | |
| 2.5% quantile | −0.0167 | −0.0162 | −0.0252 | −0.0172 | −0.0501 | −0.0280 | −0.0266 | −0.0781 | −0.0770 | |
| 97.5% quantile | 0.0164 | 0.0211 | 0.0216 | 0.0208 | 0.0481 | 0.0264 | 0.0259 | 0.0827 | 0.0741 | |
| Epithelial/Stromal/Total Corneal Thickness | Epi | Stroma | Total | Epi | Stroma | Total | Epi | Stroma | Total | |
|---|---|---|---|---|---|---|---|---|---|---|
| Mean value of the 3 repeat measurements | ROI = 3 mm | SphCyl3 | CylConoid3 | Biconic3 | ||||||
| Mean | 0.0547 | 0.4856 | 0.5403 | 0.0546 | 0.4857 | 0.5402 | 0.0546 | 0.4856 | 0.5402 | |
| SD | 0.0044 | 0.0388 | 0.0389 | 0.0044 | 0.0388 | 0.0389 | 0.0044 | 0.0388 | 0.0389 | |
| Median | 0.0547 | 0.4834 | 0.5386 | 0.0546 | 0.4835 | 0.5384 | 0.0547 | 0.4835 | 0.5385 | |
| 2.5% quantile | 0.0474 | 0.4083 | 0.4548 | 0.0474 | 0.4086 | 0.4551 | 0.0474 | 0.4086 | 0.4551 | |
| 97.5% quantile | 0.0628 | 0.5538 | 0.6123 | 0.0627 | 0.5542 | 0.6125 | 0.0627 | 0.5542 | 0.6123 | |
| ROI = 6 mm | SphCyl6 | CylConoid6 | Biconic6 | |||||||
| Mean | 0.0547 | 0.4864 | 0.5411 | 0.0546 | 0.4855 | 0.5401 | 0.0545 | 0.4855 | 0.5400 | |
| SD | 0.0043 | 0.0388 | 0.0390 | 0.0045 | 0.0388 | 0.0390 | 0.0045 | 0.0389 | 0.0390 | |
| Median | 0.0546 | 0.4854 | 0.5396 | 0.0545 | 0.4835 | 0.5384 | 0.0545 | 0.4835 | 0.5384 | |
| 2.5% quantile | 0.0479 | 0.4076 | 0.4551 | 0.0469 | 0.4086 | 0.4547 | 0.0469 | 0.4086 | 0.4548 | |
| 97.5% quantile | 0.0633 | 0.5578 | 0.6118 | 0.0626 | 0.5539 | 0.6123 | 0.0626 | 0.5555 | 0.6123 | |
| Deviation of the 3 measurements from the mean value | ROI = 3 mm | SphCyl3 | CylConoid3 | Biconic3 | ||||||
| SD | 0.0006 | 0.0008 | 0.0010 | 0.0006 | 0.0008 | 0.0009 | 0.0006 | 0.0008 | 0.0009 | |
| Median | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | |
| 2.5% quantile | −0.0010 | −0.0012 | −0.0012 | −0.0010 | −0.0011 | −0.0011 | −0.0010 | −0.0012 | −0.0012 | |
| 97.5% quantile | 0.0010 | 0.0014 | 0.0013 | 0.0010 | 0.0012 | 0.0013 | 0.0010 | 0.0013 | 0.0013 | |
| ROI = 6 mm | SphCyl6 | CylConoid6 | Biconic6 | |||||||
| SD | 0.0007 | 0.0009 | 0.0012 | 0.0007 | 0.0008 | 0.0011 | 0.0007 | 0.0009 | 0.0012 | |
| Median | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | 0.0000 | |
| 2.5% quantile | −0.0009 | −0.0014 | −0.0012 | −0.0010 | −0.0014 | −0.0012 | −0.0010 | −0.0015 | −0.0013 | |
| 97.5% quantile | 0.0010 | 0.0014 | 0.0012 | 0.0010 | 0.0014 | 0.0013 | 0.0010 | 0.0015 | 0.0013 | |
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content. |
© 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
Share and Cite
Langenbucher, A.; Szentmáry, N.; Cayless, A.; Al Karam, M.; Hoffmann, P.; Seiler, T.G.; Wendelstein, J. Repeatability of Corneal Astigmatism and Equivalent Power with the MS-39 Tomographer Derived from Model Surface Fitting in a Cataractous Population. Sensors 2025, 25, 6171. https://doi.org/10.3390/s25196171
Langenbucher A, Szentmáry N, Cayless A, Al Karam M, Hoffmann P, Seiler TG, Wendelstein J. Repeatability of Corneal Astigmatism and Equivalent Power with the MS-39 Tomographer Derived from Model Surface Fitting in a Cataractous Population. Sensors. 2025; 25(19):6171. https://doi.org/10.3390/s25196171
Chicago/Turabian StyleLangenbucher, Achim, Nóra Szentmáry, Alan Cayless, Muntadher Al Karam, Peter Hoffmann, Theo G. Seiler, and Jascha Wendelstein. 2025. "Repeatability of Corneal Astigmatism and Equivalent Power with the MS-39 Tomographer Derived from Model Surface Fitting in a Cataractous Population" Sensors 25, no. 19: 6171. https://doi.org/10.3390/s25196171
APA StyleLangenbucher, A., Szentmáry, N., Cayless, A., Al Karam, M., Hoffmann, P., Seiler, T. G., & Wendelstein, J. (2025). Repeatability of Corneal Astigmatism and Equivalent Power with the MS-39 Tomographer Derived from Model Surface Fitting in a Cataractous Population. Sensors, 25(19), 6171. https://doi.org/10.3390/s25196171

