Subsurface photodisruption in human sclera: wavelength dependence

BACKGROUND AND OBJECTIVE: Approximately 105 million people worldwide have glaucoma, and approximately 5 million are blind from its complications. Current surgical techniques often fail because of scarring of the conjunctival tissue, Tenon's tissue, or both. Femtosecond lasers can create highly precise incisions beneath the surface of a tissue, as previously demonstrated in the transparent cornea. Because the sclera is a highly scattering Subsurface, photodisruption has not been previously possible. MATERIALS AND METHODS: To overcome scattering, a laser operating at 1,700 nm was used to make subsurface cuts in human sclera in vitro via photodisruption. RESULTS: Sub-10-mum width incisions were created beneath the surface without collateral tissue effects, something not possible with shorter wavelengths used to date in corneal applications with the femtosecond laser. CONCLUSION: Completely subsurface photodisruptions can be accomplished in human sclera in vitro. In vivo studies are required to evaluate the potential use of this technology for scleral applications.