It is claimed to be more accurate than TNP and simK, especially in eyes following myopic laser ablation.
The purpose of this study was to investigate the corneal power and astigmatism distribution measured by three methods: simK, TNP, and TCRP, both before and after femtosecond laser small incision lenticule extraction (SMILE) surgery.
Corneal power was measured and shown in the power distribution display for the three methods: simK, TNP, and TCRP.
In the Pentacam program, TNP was calculated as the sum of F1 and F2.
TNP produced the smallest estimates among the three corneal powers from R1 to R8 (LSD: P < 0.05).
Postoperatively, Kms of simK, TNP, and TCRP were all significantly decreased from the preoperative Kms for R1 to R8 (paired t-test, P < 0.05).
In the current study, total corneal power was calculated by three methods: simK, TNP, and TCRP.
When analyzing the peripheral cornea, we found that TCRPs increased from the central to peripheral cornea, while both simK and TNP decreased from the central to peripheral cornea.
The results of the current study obtained following refractive surgery were consistent with those of previous studies [3-11], demonstrating that simK significantly overestimated postoperative central corneal power while TNP significantly underestimated postoperative central corneal power.
We found that simK produced the largest and TNP produced the smallest estimates of the three corneal astigmatism measurements in the central cornea.