Interferometric technique to measure biomechanical changes in the cornea induced by refractive surgery.
OBJECTIVE
To develop a technique to quantify biomechanical changes in the cornea after microkeratome incisions as would be performed in laser in situ keratomileusis.


METHODS
St Thomas' Hospital, London, and the Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, Loughborough, United Kingdom.


METHODS
Corneal displacements of whole sheep eyes were studied under hydrostatic loading using electronic speckle pattern interferometry before and after microkeratome incisions.


RESULTS
After hydrostatic loading, there was a 20.7% increase in corneal displacement in corneas with microkeratome incisions compared to unoperated corneas; this was statistically significant (P=.0068, unpaired t test).


CONCLUSIONS
Results show that in the formation of the microkeratome flap, collagen fibers are severed and minimal biomechanical loading is distributed through the flap. Corneal biomechanical integrity is compromised after microkeratome incisions.
Jaycock
Philip David
PD
Department of Ophthalmology, Rayne Institute, St. Thomas' Hospital, London, United Kingdom. philipjaycock@hotmail.com
Lobo
Leon
L
Ibrahim
Jamal
J
Tyrer
John
J
Marshall
John
J
D000818:Animals; D001696:Biomechanical Phenomena; D003094:Collagen / Q000502:physiology; D003315:Cornea / Q000502:physiology*; D019781:Corneal Topography; D003941:Diagnostic Techniques, Ophthalmological; D004547:Elastic Tissue / Q000502:physiology*; D004548:Elasticity; D006874:Hydrostatic Pressure; D007368:Interferometry / Q000379:methods*; D007429:Intraocular Pressure; D008027:Light; D012030:Refractive Errors / Q000503:physiopathology; D054140:Refractive Surgical Procedures; D012756:Sheep; D013524:Surgical Flaps
D003094:Collagen