Characteristics Of Corneal Biomechanics And Tomography In Chinese Myopia Patients With Different Corneal Diameters

TO analyze and compare the distribution characteristics of corneal biomechanics and tomographic parameters with different corneal diameters.

Patients who underwent binocular corneal refractive surgery (PRK, LASIK, or SMILE) from January to August 2021 in the refractive surgery center of Chongqing Eye and Vision Care Hospital and followed by more than two years without ectasia were selected.

Patients were grouped into four groups by corneal diameter (CD, the criteria are as follows: CD ≤ 11.0 mm, 11.0 mm<CD ≤ 11.5 mm, 11.5 mm<CD<12.0 mm, CD ≥ 12.0 mm). All cases underwent detailed preoperative corneal tomography and corneal biomechanics examinations, and indicators such as corneal diameter, corneal curvature, SP-A1, ARTh, Belin/Ambrosio enhanced ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI) and Tomographic and Biomechanical Index (TBI) were analysis.

There were a total of 403 people in this study, including 136 males (33.7%) and 267 females (66.3%). There were statistically significant differences in SP-A1, ARTh, BAD-D, CBI, and TBI indicators among the four groups (all P values <0.05). The TBI values for the CD ≤ 11.0, 11.0 mm<CD ≤ 11.5 mm, 11.5 mm<CD<12.0 mm, and CD ≥ 12.0 mm groups were 0.24 ± 0.21, 0.22 ± 0.16, 0.18 ± 0.17, and 0.12 ± 0.15 SD(P<.001). The CD has a negative correlation with BAD-D, CBI, and TBI (all P values<0.05), and multiple linear regression analysis shows TBI is negatively correlated with CD, SP-A1, and ARTh, while there is no significant correlation with Km.

Corneal diameter may affect the biomechanical results, with smaller corneal diameter often combined with larger BAD, CBI, and TBI results, so when we interpret biomechanical results, corneal diameter needs to be considered and further corrected.