Malapposition of Graft-host Interface after Keratoplasty: an Optical Coherence Tomography Study

Background: Previous studies of internal graft-host malappositions have not dealt with the precise ways in which each wound malapposition affected post-keratoplasty visual outcomes. In this study, reviewing our postsurgical keratoconic patients using anterior segment optical coherence tomography (AS-OCT) to evaluate the correlation between characteristics of the graft-host interface (GHI) and visual outcomes was aimed. Methods: Correlations between characteristics of GHI and the postsurgical visual outcomes, including logarithm of minimum angle of resolution best-corrected visual acuity (logMAR BCVA), spherical equivalent diopter (SE), diopter of spherical power (DS), diopter of cylindrical power (DC), and keratometric astigmatism, were evaluated of 45 eyes (patients). Results: The graft-host touch (GHT) varied with different alignment patterns. LogMAR BCVA correlated positively with GHT (r=0.32, P=0.030) and junctional graft thickness (Tg) (r=0.49, P=0.001). SE had positive correlation with frequency of step [F (step)] (r=0.46, P=0.001), graft step [F (graft step)] (r=0.40, P=0.028), total prevalence of malapposition proportion (Pm) (r=0.35, P=0.018), size of malapposition (Sm) (r=0.31, P=0.037), Tg (r=0.03, P=0.022), disparity between junctional graft and host thickness (|Tg-Th|) (r=0.40, P=0.007), and correlated negatively with GHT (r=-0.34, P=0.021). Similar results were acquired in DS. Keratometric astigmatism was found to correlate positively with Sm (r=0.30, P=0.047). Conclusion: In keratoconic eyes, corneal keratometric astigmatism increased by 0.017 with Sm. LogMAR BCVA increased by 0.001 with both GHT and Tg. Investigation of the visions for keratoconus patients. Our study might have potential reference value for future technological promotion.