Abstract
Purpose: :
The IntraLase femtosecond laser (AMO Corp. Santa Ana, CA) has been approved by the US Food and Drug Administration for creation of high precision corneal incisions. During normal operation, as estimated 30% of laser energy may pass beyond the cornea with potential effects on the retina. As a model for retinal laser exposure during femtosectond corneal surgery, we quantified the temperature distribution in human cadaver retinas during direct illumination by the laser.
Methods: :
The temperature increase induced by laser energy deposited in human cadaver retinas during femtosecond laser illumination was investigated in situ using an infrared thermal imaging camera (Fluke corp. Everett, WA). To model the geometry of the eye during the surgery, an approximately 10mm x 10mm excised section of human cadaver retina was placed 24 mm from the flat glass contact lens. The temperature field was observed in seven cadaver retina sections with the infrared camera at energy levels ranging from 0.4 to 1.6 µJ (corresponding to surgical energies of 1.2 to 5.0 µJ per pulse).
Results: :
A maximum temperature increase of less than 0.5°C was observed in the cadaver retina sections during laser scanning, with little variation between specimens in temperature profiles for the same laser energy illumination.
Conclusions: :
Our studies suggest that minimal retinal heating occurs during femtosecond laser corneal surgery.
Keywords: laser • refractive surgery: LASIK • retina