Table 4.

Characteristics of machine learning-assisted studies for detection of KC severity.

First Author	Year	Severity Grading (No. of Eyes)	Definition/Classification Methods	Corneal Imaging Modality	Reported Sensitivity in Detection of Each Severity Level
Maeda et al. [12]	1995	Mild (15) Moderate (18) Advanced (11)	NA	TMS-1	Mild: 100% Moderate: 100% Advanced: 91%
Kamiya et al. [42]	2019	Grade 1 (108) Grad e2 (75) Grade 3 (42) Grade 4 (79)	Amsler–Krumeich classification	AS-OCT	Grade 1: 88.9% Grade 2: 68% Grade 3: 71.4% Grad e4: 74.7%
Issarti et al. [33]	2019	Mild KC (220)	a Self-defined	Pentacam	98.81%
Issarti et al. [33]	2019	Moderate KC (229)	b Self-defined	Pentacam	99.91%
Bolarin et al. [35]	2020	Grade I (44) Grade II (18) Grade III (15) Grade IV (15) Grade IV plus (15)	RETICS grading	Sirius	Grade I: 59.1% Grade II: 33.3% Grade III: 40% Grade IV: 80% Grade IV plus: 86.7%
Velazquez-Blazquez et al. [40]	2020	Mild KC (42)	RETICS grading	Sirius	Mild KC: 63%

^a A clear cornea, tomography maps compatible with KC, a Fleischer ring at the apex base, slight thinning, and anterior and/or posterior corneal steepening; ^b Slit-lamp findings compatible with KC, corneal thinning at the apex, Vogt striae, a clearly visible Fleischer ring and corneal tomography compatible with KC; The severity of KC was considered to be increasing from Grade 1 to Grade 4 and for Grade I to Grade IV plus.