We analyzed the central corneal and graft–host junction (GHJ) thickness profiles in cases with signs of corneal ectasia after penetrating keratoplasty for keratoconus.
Anterior segment optical coherence tomography (ASOCT) was performed in cases with clinical or topographic signs of ectasia after complete suture removal. Corneal thickness was measured on the GHJ and at 1 mm on either side of the GHJ. Corneal thickness maps using Scheimpflug imaging were obtained.
Eight patients (11 eyes) with an average age of 52.55 ± 10.13 years were included. Mean age of the corneal grafts was 25.83 ± 12.37 years. Mean central corneal thickness was 577.45 ± 78.52 (range, 486–704) μm. Mean thickness 1 mm inside the GHJ, at the GHJ, and 1 mm outside the GHJ was 511.81 ± 66.15 (range, 380–600), 438.18 ± 86.35 (range, 260–550), and 465.45 ± 110.93 (range, 320–690) μm, respectively. Thinning of the graft, GHJ, or the host cornea was seen on ASOCT in all eyes. The central graft thickness was significantly higher compared with the graft thickness at and around the GHJ (P < 0.05 for all). The inferonasal quadrant was the thinnest in 7 eyes (63.63%).
Corneal thinning beyond the GHJ and subsequent ectasia can occur many years after initial keratoplasty in cases with keratoconus. Long-term follow-up of these cases may be desirable after corneal transplantation surgery. ASOCT is a useful tool for monitoring corneal thickness at and around the GHJ.