Abstract
Purpose: :
To investigate corneal biomechanical changes in keratoconus after penetrating keratoplasty.
Methods: :
The study was conducted at Duke University as a retrospective chart review. Twenty one keratoconus eyes were analyzed. Control eyes did not undergo surgical interventions. Cases were keratoconus eyes that underwent penetrating keratoplasty. Eyes with conditions that might affect corneal biomechanical measurements, such as a history of corneal infection or trauma, were excluded. Main outcome measures were taken with the Ocular Response Analyzer (ORA; Reichert; Depew, NY): corneal hysteresis (CH), corneal resistance factor (CRF), Goldman correlated intraocular pressure (IOPg) and compensated intraocular pressure (IOPcc).
Results: :
Control keratoconus eyes had average CRF, CH, IOPg and IOPcc values of 6.02+/-0.71, 7.05+/-0.61, 10.35+/-1.17, and 15.18+/-1.01 respectively. Keratoconus eyes with penetrating keratoplasty had statistically increased values of CRF, CH and IOPg: 10.33+/-1.28 (p=0.0003), 10.20+/-0.80 (p<0.0001), and 15.8+/-3.30 (p=0.02) respectively. IOPcc was not statistically affected with penetrating keratoplasty: 16.49+/-2.85 (p=0.43).
Conclusions: :
Eyes with keratoconus that underwent penetrating keratoplasty had an increase in corneal hysteresis (71%) and corneal resistance factor (45%), approaching normal corneal values.
Keywords: keratoconus • cornea: clinical science