| Study characteristics |
| Patient Sampling |
Case‐control study that recruited participants from the Casey Eye Institute at Oregon Health & Science University (Portland, Oregon) and the Affiliated Eye Hospital of Wenzhou Medical College (Wenzhou, China) |
| Patient characteristics and setting |
The study grouped eyes as follows.
Normal eyes: normal slit‐lamp examination, corrected distance visual acuity (CDVA) ≥ 20/20, normal topography appearance, and KISA% index < 100% Keratoconus eyes: manifest, subclinical, and forme fruste
|
| Index tests |
Custom‐made MATLAB algorithms generated pattern deviation maps of pachymetry and epithelial thickness, captured using Fourier‐domain OCT images of the cornea. The co‐localized thinning of the 2 maps was quantified using a novel coincident thinning index, which was calculated from Gaussian fits of the regions of maximum relative thinning. |
| Target condition and reference standard(s) |
OCT scans were obtained using commercial Fourier‐domain OCT systems (RTVue or Avanti; Optovue, Inc) with a corneal adaptor module for imaging of the anterior eye. It is unclear how the diagnosis was made. It seems the cases were divided into normal and keratoconus groups before they were analysed with the algorithm. |
| Flow and timing |
It is unclear if all cases received the same reference standard. All data were included in a 2 × 2 table. |
| Comparative |
Not applicable |
| Notes |
Supported by the National Institutes of Health, Bethesda, MD (Grant Nos. R01EY028755, R01EY029023, T32EY023211, and P30EY010572); a research grant and equipment support from Optovue, Inc, Fremont, California; and unrestricted grants to Casey Eye Institute and Bascom Palmer Eye Institute from Research to Prevent Blindness, Inc, New York, New York. |
| Methodological quality |
| Item |
Authors' judgement |
Risk of bias |
Applicability concerns |
| DOMAIN 1: Patient selection |
| Was a consecutive or random sample of patients enrolled? |
No |
|
|
| Was a case‐control design avoided? |
No |
|
|
| Did the study avoid inappropriate exclusions? |
No |
|
|
| Could the selection of patients have introduced bias? |
|
High risk |
|
| Are there concerns that the included patients and setting do not match the review question? |
|
|
High |
| DOMAIN 2: Index test (All tests) |
| Were the index test results interpreted without knowledge of the results of the reference standard? |
Yes |
|
|
| If a threshold was used, was it pre‐specified? |
Yes |
|
|
| Was the model designed in an appropriate manner? |
Yes |
|
|
| Could the conduct or interpretation of the index test have introduced bias? |
|
Low risk |
|
| Are there concerns that the index test, its conduct, or interpretation differ from the review question? |
|
|
Low concern |
| DOMAIN 3: Reference standard |
| Is the reference standard likely to correctly classify the target condition? |
Unclear |
|
|
| Were the reference standard results interpreted without knowledge of the results of the index tests? |
Yes |
|
|
| Could the reference standard, its conduct, or its interpretation have introduced bias? |
|
Unclear risk |
|
| Are there concerns that the target condition as defined by the reference standard does not match the question? |
|
|
Low concern |
| DOMAIN 4: Flow and timing |
| Did all patients receive the same reference standard? |
Unclear |
|
|
| Were all patients included in the analysis? |
Yes |
|
|
| Could the patient flow have introduced bias? |
|
Unclear risk |
|
| DOMAIN 5: Comparative |
