Evidence map›Paper›PMID 40536262›Full record

ArticleOphthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists)2025

Deciphering the performance of different surface models for corneal topography.

Achim Langenbucher, Nóra Szentmáry, Alan Cayless, Peter Hoffmann, Jascha Wendelstein

Abstract read
In one paragraph

Article in Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists), 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Deciphering the performance of different surface models for corneal topography.Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians (Optometrists) · 2025
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Achim LangenbucherDepartment of Experimental Ophthalmology, Saarland University, Homburg/Saar, Germany.ORCID https://orcid.org/0000-0001-9175-6177
Nóra SzentmáryDr. Rolf M. Schwiete Centre for Limbal Stem Cell and Aniridia Research, Saarland University, Homburg/Saar, Germany.
Alan CaylessSchool of Physical Sciences, The Open University, Milton Keynes, UK.
Peter HoffmannAugen- Und Laserklinik Castrop-Rauxel, Castrop-Rauxel, Germany.
Jascha WendelsteinDepartment of Experimental Ophthalmology, Saarland University, Homburg/Saar, Germany.ORCID https://orcid.org/0000-0003-4145-2559

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

purposeTo study the performance of different corneal surface models to be used for ray tracing. Models based on geometric surfaces and polynomial fits were compared and the differences discussed.

methodsFor this simulation study, five characteristic generic surface configurations were generated: (A) perfect biconic, (B) decentred biconic with white noise, (C) biconic with paracentral hollow simulating the situation after myopic LASIK, (D) biconic with random dot irregularities and (E) rotationally symmetric conic with mid-peripheral bump simulating the situation of corneal ectasia. A floating best fit sphere (BFS), conic (BFC), biconic (BFBC), fringe Zernike on top of a BFS (BFSZ), fringe Zernike (BFZ) and Gaussian process surface model (BFGP) were fitted and the root-mean-squared fit error was analysed.

resultsSurfaces A and B were well described by BFBC, BFSZ, BFZ and BFGP, but not by BFS and BFC. Surface C was not well represented by BFS, BFC and BFBC, but reasonably with BFSZ and BFZ and quite well with BFGP. Surfaces D and E were poorly represented, especially with BFS, BFC and BFBC, but also with BFSZ and BFZ and quite well with BFGP. There was no systematic difference between the two Zernike representations BFSZ and BFZ, even for surface B.

conclusionsRepresenting corneal point cloud data with a closed surface model plays a key role in ray tracing. Simple surface models such as BFS, BFC or BFBC are easy to handle but do not fully represent clinical situations with local irregularities after corneal refractive surgery or with ectasia.

Indexed as

CorneaCorneal TopographyComputer SimulationHumansKeratomileusis, Laser In SituMyopiacorneal surface fittingGaussian process surfacemodel surfacesraytracingZernike surface

Identifiers

PMID40536262
PMCPMC12357221

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.