Kamiya 2021.
| Study characteristics | |||
| Patient Sampling | Retrospective, single‐centre (Japan), case‐control study involving 349 keratoconus eyes and 170 normal eyes (refractive surgery candidates, contact lens fitting candidates). | ||
| Patient characteristics and setting | A total of 349 eyes with good‐quality images of corneal topography measured with a Placido disc corneal topographer (TMS‐4 TM, Tomey, Aichi, Japan) were included. The disease was graded according to the Amsler‐Krumeich classification, as follows.
Control group: 170 eyes in people with normal ocular findings applying for a contact lens fitting or for a refractive surgery consultation, who had a refractive error of < 6 D as well as astigmatism of < 3 D. |
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| Index tests | Deep learning (convolutional neural network) of a single colour‐coded topography map. | ||
| Target condition and reference standard(s) | Multiple corneal specialists diagnosed keratoconus with distinctive features (e.g. corneal colour‐coded map with asymmetric bowtie pattern with or without skewed axes), and ≥ 1 keratoconus sign (e.g. stromal thinning, conical bulging, Fleischer's ring, Vogt's striae, or apical scar). It is unclear how many corneal specialists classified the cases; however, classification was performed before inclusion. | ||
| Flow and timing | All cases were included in the reference standard and index test. All data were included in a 2 × 2 table. | ||
| Comparative | Not applicable | ||
| Notes | This work was in part supported by Grants‐in‐Aid for Scientific Research (Grant Number 21K09706). | ||
| 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? | Unclear | ||
| 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? | Unclear | ||
| 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? | Yes | ||
| 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? | Low 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? | Yes | ||
| Were all patients included in the analysis? | Yes | ||
| Could the patient flow have introduced bias? | Low risk | ||
| DOMAIN 5: Comparative | |||