Dr.Arpitha Pereira, P15817, Dr. V. Thangavelu
Aim: To investigate agreement between 3 different keratometers- IOL master 500,(IM)
automated keratometer (TOPCON KR8800) and manual keratometer (Bausch and
Lomb manual keratometer)
Materials methods: Keratometry values were obtained in diopters, directly from the instruments.
Corneal powers of the two principal meridians were averaged for analysis.
Keratometric astigmatism was transformed into rectangular coordinate system J180 and J45
which allows the simultaneous analysis of the strength and orientation (axis) of astigmatism.
Results: The paired t‑test demonstrated a statistically significant difference in the mean corneal power between the IM and MK (p = 0.009),mean corneal power between the AR and MK(p < 0.0001) and mean corneal power between the IM and AR(p < 0.0001).
Conclusions: Keratometry data obtained with different instruments may not be interchangeable, a
fact that has important implications for cataract surgeons with respect to both surgical
planning and outcomes auditing