Evidence map›Paper›PMID 30399144›Full record

ArticlePloS one2018

Keratoconus severity identification using unsupervised machine learning.

Siamak Yousefi, Ebrahim Yousefi, Hidenori Takahashi, Takahiko Hayashi, Hironobu Tampo, Satoru Inoda, Yusuke Arai, Penny Asbell

Abstract read
In one paragraph

Article in PloS one, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 52 papers, 4 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
52citing papers in PubMed, 4 pooled it
–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

52 citing papers in PubMed, 4 syntheses or guidelines pooled it.

  1. Pooled it
  2. Comparison of different corneal imaging modalities using artificial intelligence for diagnosis of keratoconus: a systematic review and meta-analysis.Graefe's archive for clinical and experimental ophthalmology = Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie · 2024
    Pooled it
  3. Pooled it
  4. Artificial intelligence for detecting keratoconus.The Cochrane database of systematic reviews · 2023
    Pooled it
  5. Article
  6. Article
  7. Review
  8. Observational
  9. Screening with the Bilateral Corneal Symmetry 3-D Analyzer.International journal of environmental research and public health · 2025
    Article
  10. Review
  11. An explainable unsupervised learning approach for anomaly detection on cornealFrontiers in bioengineering and biotechnology · 2025
    Article
  12. Article
  13. Article
  14. Review
  15. Review
  16. Observational
  17. Deep learning in precision medicine and focus on glioma.Bioengineering & translational medicine · 2023
    Review
  18. Performance of ChatGPT in Diagnosis of Corneal Eye Diseases.medRxiv : the preprint server for health sciences · 2023
    Article
  19. Review
  20. 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

8 authors.

Siamak YousefiDepartment of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.ORCID 0000-0001-8633-5730
Ebrahim YousefiDepartment of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.
Hidenori TakahashiDepartment of Ophthalmology, Jichi Medical University, Tochigi, Japan.ORCID 0000-0001-5331-4730
Takahiko HayashiDepartment of Ophthalmology, Yokohama Minami Kyosai Hospital, Kanagawa, Japan.ORCID 0000-0001-8704-680X
Hironobu TampoDepartment of Ophthalmology, Jichi Medical University, Tochigi, Japan.
Satoru InodaDepartment of Ophthalmology, Jichi Medical University, Tochigi, Japan.
Yusuke AraiDepartment of Ophthalmology, Jichi Medical University, Tochigi, Japan.
Penny AsbellDepartment of Ophthalmology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

We developed an unsupervised machine learning algorithm and applied it to big corneal parameters to identify and monitor keratoconus stages. A big dataset of corneal swept source optical coherence tomography (OCT) images of 12,242 eyes acquired from SS-1000 CASIA OCT Imaging Systems in multiple centers across Japan was assembled. A total of 3,156 eyes with valid Ectasia Status Index (ESI) between zero and 100% were selected for the downstream analysis. Four hundred and twenty corneal topography, elevation, and pachymetry parameters (excluding ESI Keratoconus indices) were selected. The algorithm included three major steps. 1) Principal component analysis (PCA) was used to linearly reduce the dimensionality of the input data from 420 to eight significant principal components. 2) Manifold learning was used to further reducing the selected principal components nonlinearly to two eigen-parameters. 3) Finally, a density-based clustering was applied to the eigen-parameters to identify eyes with keratoconus. Visualization of clusters in 2-D space was used to validate the quality of learning subjectively and ESI was used to assess the accuracy of the identified clusters objectively. The proposed method identified four clusters; I: a cluster composed of mostly normal eyes (224 eyes with ESI equal to zero, 23 eyes with ESI between five and 29, and nine eyes with ESI greater than 29), II: a cluster composed of mostly healthy eyes and eyes with forme fruste keratoconus (1772 eyes with ESI equal to zero, 698 eyes with ESI between five and 29, and 117 eyes with ESI greater than 29), III: a cluster composed of mostly eyes with mild keratoconus stage (184 eyes with ESI greater than 29, 74 eyes with ESI between five and 29, and 6 eyes with ESI equal to zero), and IV: a cluster composed of eyes with mostly advanced keratoconus stage (80 eyes had ESI greater than 29 and 1 eye had ESI between five and 29). We found that keratoconus status and severity can be well identified using unsupervised machine learning algorithms along with linear and non-linear corneal data transformation. The proposed method can better identify and visualize the keratoconus stages.

Indexed as

Severity of Illness IndexUnsupervised Machine LearningAgedAlgorithmsCorneaDilatation, PathologicFemaleHumansKeratoconusMalePrincipal Component Analysis

Identifiers

PMID30399144
PMCPMC6219768

What OpenQuestion holds

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LicenceCC BY
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Registered trials

None linked

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.