Nonlinear optical photodynamic therapy (NLO-PDT) of the cornea

摘要

The embodiments include method of nonlinear optical photodynamic therapy of tissue including the steps of providing pulsed infrared laser light for two-photon excited fluorescence tissue exposure, and selectively focusing the pulsed infrared laser light within the tissue at a focal plane to activate a photosensitizing agent to generate free radicals within a highly resolved axial and lateral spatial domain in the tissue. The invention is also directed to an apparatus for performing nonlinear optical photodynamic therapy of tissue including a pulsed infrared laser for providing two-photon excited fluorescence beam tissue exposure, a scanner for selectively and controllably moving the tissue and the beam relative to each other, and optics for selectively focusing the pulsed infrared laser light within the tissue at a point in a focal plane to activate a photosensitizing agent to generate free radicals within a highly resolved axial and lateral spatial domain in the tissue.

主权项

1. An apparatus configured to perform nonlinear optical photodynamic clinical therapy of a cornea of an eye comprising:
a pulsed infrared laser configured to provide a multiphoton beam at a predetermined intensity and having a beam width; a scanner configured to selectively and controllably move the beam relative to the cornea in an x and y plane; a variable beam expander configured to selectively vary the beam width; and a focusing objective lens configured to:
focus the beam at a depth in the cornea with a selected focal volume, andmove relative to the cornea along a z axis perpendicular to the x and y plane to selectively position the depth of the beam in the cornea, wherein the variable beam expander is configured to selectively adjust an effective numerical aperture of the focusing objective lens by varying the beam width incident on the focusing lens and hence the focal volume of the beam in the cornea, wherein the beam expander is configured to vary the effective numerical aperture between 0.16 and 0.08 and the focal volume between 150 and 2500 femtoliters respectively, and the apparatus is configured to achieve collagen cross-linking of the entire cornea in less than 10 minutes using a selected scanner speed and a focal volume between 150 and 2500 femtoliters.