Abstract:AIM: To compare the distribution characteristics of axial sagittal front power(ASF), true net power(TNP), total corneal refractive power(TCRP)and the difference in back-front corneal radius ratio(B/F ratio)after cataract surgery.
METHODS: A prospective study. A total of 156 patients(156 eyes)with age-related cataract who attend Weifang Eye Hospital for cataract surgery from December 2020 to May 2021 were collected. Pentacam was performed before operation and 3mo after operation to collect ASF, TNP and TCRP on 2, 4 and 6mm diameters rings and areas on the corneal apex and pupil-centered, as well as B/F ratio.
RESULTS: 3mo after operation, there was no statistical difference in ASF on the 2mm diameters ring and area centered on the corneal apex compared with preoperative values(all P>0.05), however, the ASF values on the 4 and 6mm diameters rings and areas were significantly different from those before surgery(all P<0.05); There was no statistical difference in ASF on the 2mm diameters rings and areas centered on the pupil compared with preoperative values(all P>0.05). The postoperative values of TNP and TCRP on the 2, 4 and 6mm diameters rings and areas centered on the corneal apex and centered on the pupil were statistically different before surgery(all P<0.05). Preoperative, TCRP values were different between 2mm and 6mm and between 4mm and 6mm on both corneal apex and pupil-centered rings(all P<0.0167), TCRP values were all different between 2mm and 6mm diameters areas on corneal apex and pupil-centered(all P<0.0167); 3mo after operation, TCRP values were different on corneal apex and pupil-centered rings between 2mm and 6mm and between 4mm and 6mm diameters(all P<0.0167). While TCRP values on the corneal apex and pupil-centered areas were only different between 2mm and 6mm diameters(all P<0.0167). The preoperative B/F ratio of patients was 81.79%±1.87%, and the postoperative B/ F ratio of patients was 80.68%±2.23%(P<0.001).
CONCLUSION: Corneal parameters of different diameters of rings and areas centered on the corneal apex and pupil before and after cataract surgery may change and differ, which should be taken into account when selecting the K value for intraocular lens calculation and individualizing the selection of IOLs based on corneal characteristics.