comparison of cornel graft biomechanical properties following penetrating keratoplasty and deep anterior lamellar keratoplasty using the ocular response analyzer

purpose: to compare corneal hysteresis and resistance factor after penetrating keratoplasty (pk) and deep anterior lamellar keratoplasty (dalk) using anwar’s big-bubble technique using the ocular response analyzer. methods: forty-five pk eyes and 23 dalk eyes with keratoconus were compared in terms of corneal hysteresis (ch), corneal resistance factor (crf), goldmann-correlated intraocular pressure (iopg) and cornea-compensated iop (iopcc). results: mean age was 29.8±6.1 years in the pk group and 27.2±6.5 years in the dalk group (p=0.11); patients were followed for 31.4±19.0 and 29.2±17.3 months after corneal transplantation, respectively (p=0.27). there was no significant difference between the study groups in terms of recipient (p=0.21) and donor (p=0.57) trephine size or bscva (p=0.77). mean ch was 10.09±2.5 mmhg in the pk group and 9.64±2.1 mmhg in the dalk group (p=0.36); mean crf was 10.13±2.2 and 9.36±2.1 mmhg, respectively (p=0.17). no significant difference was found between the study groups in terms of iopg (p=0.25) and iopcc (p=0.80). conclusion: pk and dalk techniques provide comparable graft biomechanics in keratoconic eyes.