Indian J Ophthalmol. 2026 Feb 11. doi: 10.4103/IJO.IJO_1029_25. Online ahead of print.
ABSTRACT
PURPOSE: Comparative evaluation of the corneal biomechanical parameters by the dynamic corneal response imaging with CORVIS-ST ST in normal and post-keratoplasty eyes.
METHODS: Cross-sectional observational study of CORVIS-ST imaging of 150 normal corneas and 150 post-keratoplasty corneas was done to evaluate corneal biomechanics of normal Asian-Indian corneas and post-keratoplasty corneas. Data on demographic details, postoperative period, visual acuity (UCVA, BCVA) (logmar units), refraction, axial length (D), corneal topography Scheimpflug’s imaging with Pentacam [Anterior-K1(AK1), Anterior-K2 (AK2), Posterior-K1(PK1), PosteriorK2(PK2), Mean keratometry (Kmean), Keratometry maximum (Kmax), Q-value, D-value, Thinnest pachymetry (TP), Corneal elevation [anterior (CE ant) and posterior (CE post)], CORVIS-ST imaging (bIOP, 1st and 2nd Appl time HCT, 1st Appl length, DA, TBI, CBI, HC rad, Vel in and out, DA ratio, IR, Inv CR, SSI, SPA1, ARTh) were recorded.
RESULTS: Comparative evaluation of CORVIS-ST in 150 normal corneas [mean age 32.54 ± 10 (9-68) years] and 150 post-keratoplasty corneas [mean age 35.14 ± 16.96 (8-72) years; PK (58), DSAEK (29), DALK (58), HALK (8), and SALK (3)] noted 18 parameters (bIOP, 1st and 2nd Appl time HCT, 1st Appl length, DA, TBI, CBI, HC rad, Vel in and out, DA ratio, IR, Inv CR, SSI, SPA1, ARTh) and showed that 12 of these were statistically different in post-keratoplasty corneas. Parameters of DA, TBI, CBI, IR, and Inv CR were higher, whereas HC rad, SSI, SPA1, and ARTh showed significantly lesser values in post-keratoplasty corneas as compared to normal corneas. Subgroup analysis (PK, DSAEK, DALK, HALK) showed eyes that underwent DSAEK had biomechanical values closest to that of normal corneas. Post-DALK in comparison to post-PK corneas showed significantly higher values in CBI and IR, and lower values in HC rad, SSI, and ARTh (0.87 ± 0.17, 9.9 ± 3.5, 0.85 ± 0.25, 190.92 ± 119.06 and 0.71 ± 0.25, 8.19 ± 1.92, 1.02 ± 0.38, and 340.90 ± 178.37, respectively). Correlational analysis showed significant mild positive correlation of CBI with corneal curvature in normal and post-PK corneas (P = 0.004 and 0.040, respectively).
CONCLUSION: Post-keratoplasty corneas were seen to have lesser biomechanical strength as compared to normal corneas. Post-DSAEK corneas had a better biomechanical strength than other groups and closest biomechanics to normal corneas. Post-DALK in comparison to post-PK corneas showed a lower biomechanical strength in our study.
PMID:41669797 | DOI:10.4103/IJO.IJO_1029_25
