Correlation of graft–host interface to refractive outcomes after penetrating keratoplasty using anterior segment optical coherence tomography

Objective The aim of this study was to evaluate the correlation between the graft–host interface and the refractive outcomes after penetrating keratoplasty (PKP) using anterior segment optical coherence tomography. Patients and methods A total of 40 eyes of 38 patients with different corneal pathologies (bullous keratopathy, seven eyes; corneal scar, 20 eyes; and keratoconus, 13 eyes) who underwent PKP were retrospectively reviewed. The wound profiles of the graft–host junctions were classified into well-apposed junction and malapposed one including gap, step, and protrusion with the aid of spectral domain anterior segment optical coherence tomography. The correlations between clinical outcomes and post-PKP wound characteristics were analyzed. Results A total of 320 graft–host junctions from 40 eyes were examined, of which, 130 (40.6%) sections showed a well-apposed junction and 190 (59.4%) sections represented a malapposed junction. The most recorded type of malapposition was protrusion (97 sections=30.3%). When referring to the underlying diseases, well-opposed junctions were most frequently met in bullous keratopathy (66.1%). The alignment pattern showed highly significant differences between the preoperative original disease groups (P=0.001). Spherical equivalent and corrected distant visual acuity showed highly significant differences between the alignment groups, with highest myopic shift in the gap malapposition. Graft–host thickness disparities showed no significant correlations with spherical equivalent (r=−0.184, P= 0.256). Conclusion The alignment pattern of graft–host junctions after PKP varied according to the preoperative original disease and was significantly associated with spherical equivalent and visual acuity.