Carvalho 2005.

Study characteristics
Patient Sampling	Retrospective, single‐centre case‐control study. 80 corneal maps were selected from the database of the EyeSys System 2000 (EyeSys Vision, Houston, TX) topographer in Brazil.
Patient characteristics and setting	80 corneal maps of different people were selected according to the following 5 categories (16 corneas for each category). Regular cornea With‐the‐rule astigmatisms Against‐the‐rule astigmatisms Keratoconus Post‐LASIK Criteria for diagnosis of keratoconus are unclear. Corneal maps had few or no nose or eyelid shadows; only the right eye of each person was allowed. Right and left eyes of the same person were not used. The investigators excluded corneas with incipient keratoconus, keratoconus with high degrees of symmetrical astigmatism, and other cases for which a single prevailing diagnosis could not be issued. In the case of regular profiles, given that even the most symmetrical corneas have some degree of with‐the‐rule astigmatism, only corneas with simulated keratometry 0.25 D were considered "regular" or "normal."
Index tests	A neural network which used the first 15 Zernike coefficients
Target condition and reference standard(s)	The selection and classification were performed by 2 eye care specialists, with unclear criteria. However, cases were classified before inclusion.
Flow and timing	All cases were included in the reference standard and index. All data were included in a 2 × 2 table.
Comparative	Not applicable
Notes	Supported in part by FAPESP (São Paulo Research Foundation) process #03132–8.
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?	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