Graft Biomechanical Properties after Penetrating Keratoplasty versus Deep Anterior Lamellar Keratoplasty

Abstract

Purpose: To compare biomechanical properties of transplanted corneas after penetrating keratoplasty (PK) with those after deep anterior lamellar keratoplasty (DALK) using Anwar’s big-bubble technique.

Materials and Methods: This cross-sectional comparative study consisted of 45 PK eyes (group 1) and 23 DALK eyes (group 2) with the underlying pathology of keratoconus. The Ocular Response Analyzer was used to measure Goldmann-correlated intraocular pressure (IOPg) and cornea-compensated IOP (IOPcc), as well as graft biomechanical properties, namely corneal hysteresis (CH) and corneal resistance factor (CRF). The results were compared between the study groups using independent t-test.

Results: Mean patient age was 29.8 ± 6.1 years in group 1 and 27.2 ± 6.5 years in group 2 (P = 0.11) and they were followed up for 31.4 ± 19.0 months 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 sizes or BSCVA (P = 0.77). CH was measured 10.09 ± 2.5 mmHg in group 1 and 9.64 ± 2.1 mmHg in group 2 (P = 0.36). CRF was 10.13 ± 2.2 and 9.36 ± 2.1 mmHg, respectively (P = 0.17). Similarly, no significant difference was found between group 1 and group 2 in terms of IOPg (P = 0.25) and IOPcc (P = 0.80).

Conclusion: DALK using the big-bubble technique for keratoconic eyes provides corneal biomechanics comparable to PK.

Keywords::

• Deep anterior lamellar keratoplasty
• Graft biomechanical properties
• Keratoconus
• Ocular Response Analyzer
• Penetrating keratoplasty

Declaration of interest: There is no financial interest or propriety interest in any of the materials used in this manuscript. The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.