The Influence Of Different Corneal Diameters On The Parameters Of Pentacam Corneal Topography & Corvis Corneal Biomechanics

To identify the influence of corneal diameter on the results of Pentacam corneal topography and Corvis corneal biomechanics.

Wuhan Bright Eye Hospital, Wuhan, China

Retrospective observational study. The subjects were 152 myopia patients who intended to receive corneal refractive surgeries from May to July, 2021. They were divided into three groups according to their corneal diameters measured by Pentacam, ie. Group A, corneal diameters were less than 11.2 mm, Group B ranged from 11.2 to 11.8 mm and Group C were more than 11.8 mm. Preoperative parameters included Df, Db, Dp, Dt, Da, D, PTE, ARTH, SP-A1, IR, DAR, CBI, TBI were measured by Pentacam and Corvis, respectively. The mean between groups was compared by one-way ANOVA of completely random design data; the distribution of related results of BAD index was tested by Chi-square test.

In group A, B & C, Df were 0.24±1.05, 0.15±0.92, -0.09±0.98, Db were 1.65±1.07, 0.17±0.73, -0.5±0.71, Dp were 1.08±0.80, 0.99±0.71, 0.22±0.75, Dt were -0.67±0.98, -0.15±0.72, 0.08±0.91, Da were 0.39±0.81, 0.53±0.62, 0.2±0.72, D were 1.41±0.63, 1.08±0.51, 0.58±0.59, PTE were 8.75±4.52, 4.92±3.09, 3.69±3.93, ARTH were 457.47±79.62, 480.74±83.54, 524.07±95.38, SP-A1 were 102.88±17.32, 95.73±13.28, 96.36±17.59, IR were 7.9±1.13, 8.19±1.00, 7.97±1.01, DAR were 4.06±0.40, 4.08±0.40, 4.16±0.45, CBI were 0.15±0.23, 0.13±0.19, 0.15±0.27, TBI were 0.36±0.27, 0.28±0.22, 0.26±0.26. Db, Dp, Dt, Da, D, PTE, ARTH had significant statistical difference. The proportion of normal and abnormal BAD parameters of Db, Dp, Da, and D were significantly different.

Corneal diameter has a significant effect on the results of corneal topography, while it has little influence on corneal biomechanics. Furthermore, the biomechanical results can be used to correct topography deviation.