Evaluating keratometry and corneal astigmatism data from biometers and anterior segment tomographers and mapping to reconstructed corneal astigmatism

• DOI: 10.1111/ceo.14387
• Publication Date: 2024-05-14T03:25:02Z
• Authors: Achim Langenbucher; Leonardo Taroni; Catarina P. Coutinho; Alan Cayless; Nóra Szentmáry; Peter Hoffmann; Jascha Wendelstein; Giacomo Savini
• Keywords: Astigmatism

Abstract Background To compare results from different corneal astigmatism measurement instruments; to reconstruct the postimplantation spectacle refraction and toric intraocular lens (IOL) power; derive models for mapping measured reconstructed astigmatism. Methods Retrospective single centre study involving 150 eyes treated with a IOL (Alcon SN6AT, DFT or TFNT). Measurements included IOLMaster 700 keratometry (IOLMK) total (IOLMTK), Pentacam (PK) refractive power in 3 4 mm zones (PTCRP3 PTCRP4), Aladdin (AK). Regression‐based C0 C45 components (Alpin's method) were derived. Results Mean 0.50/0.59/0.51 dioptres (D) IOLMK/PK/AK; 0.2/0.26/0.31 D IOLMTK/PTCRP3/PTCRP4; 0.26 All corresponding ranged around 0. The prediction had main diagonal elements lower than 1 some crosstalk between (nonzero off‐diagonal elements). Root‐mean‐squared residuals 0.44/0.45/0.48/0.51/0.50/0.47 IOLMK/IOLMTK/PK/PTCRP3/PTCRP4/AK. Conclusions modalities are not consistent. On average IOLMTK/PTCRP3/PTCRP4 match astigmatism, whereas IOLMK/PK/AK show systematic offsets of 0.25 D. IOLMTK/PTCRP3/PTCRP4. Prediction can reduce but fully eliminate residual after implantation.