Therapeutics Advances
Copyright ©2013 Baishideng Publishing Group Co.
World J Ophthalmol. Aug 12, 2013; 3(3): 20-31
Published online Aug 12, 2013. doi: 10.5318/wjo.v3.i3.20
Table 1 Clinical classification of keratoconus[3]
StageCharacteristics
Stage IEccentric bulging
Induced myopia and/or astigmatism of 5 D
Average central keratometry of 48 D
Stage IIInduced myopia and/or astigmatism of 5 to 8 D
Average central keratometry > 48 D but < 53 D
Absent scarring
Minimum corneal thickness of 400 microns
Stage IIIInduced myopia and/or astigmatism of 8 to 10 D
Average central keratometry > 53 D
Absent scarring
Central corneal thickness of 300 to 400 microns
Stage IVInvaluable refraction
Average central keratometry > 55 D
Central corneal scar
Corneal thickness < 200 microns