Devices and techniques for light-mediated stimulation of trabecular meshwork in glaucoma therapy

Abstract

An apparatus and technique for transscleral light-mediated biostimulation of the trabecular plates of a patient's eye in a treatment for glaucoma or ocular hypertension. The apparatus includes; (i) a working end geometry for contacting the anterior surface of the sclera and cornea to insure that a laser emission reaches the trabecular meshwork from a particular location on the anterior surface of the sclera, (ii) a laser energy source providing a wavelength appropriate for absorption beneath the anterior scleral surface to the depth of the trabecular plates, and (iii) a dosimetry control system for controlling the exposure of the laser emission at the particular spatial locations. The device uses a light energy source that emits wavelengths in the near-infrared portion of the spectrum, preferably in the range of about 1.30 μm to 1.40 μm or from about 1.55 μm to 1.85 μm. The depth of absorption of such wavelength ranges will extend through most, if not all, of the thickness of the sclera (750 μm to 950 μm). In accordance with a proposed method of trabecular biostimulation, the targeted region is elevated in temperature to a range between about 40° C. to 55° C. for a period of time ranging from about 1 second to 120 seconds or more.

What is claimed is:  
     
         1 . A method for delivering energy to trabecular meshwork in a patient's eye, comprising: 
 positioning a working face of a member in contact with a patient's sclera overlying the trabecular meshwork; and    delivering at least one laser beam through the member wherein said at least one beam is transmitted transclerally to irradiate a region of said trabecular meshwork.    
     
     
         2 . The method of  claim 1  wherein said at least one beam has a wavelength range from about of 1.30 μm to 1.85 μm.  
     
     
         3 . The method of  claim 1  further comprising the steps of: 
 sensing a temperature of the sclera overlying the trabecular meshwork with at least one sensor in said member to provide a signal; and  
 modulating or terminating the delivery of said at least one laser beam in response to said signal.  
 
     
     
         4 . The method of  claim 3  further comprising the step of elevating the temperature of said trabecular meshwork to a range between about 40° C. to 55° C.  
     
     
         5 . A method for delivering energy to a patient's trabecular meshwork to treat glaucoma, comprising the steps of: 
 (a) placing a laser emitter in contact with a portion of the sclera of the patient's eye overlying the trabecular meshwork;    (b) delivering laser energy from the emitter at a wavelength ranging between about 1.30-1.40 μm or 1.55-1.85 μm; and    (c) modulating the power level, pulse duration and pulse intervals of the laser energy to maintain the temperature of the trabecular meshwork at less than about 60° C.    (d) wherein said laser energy delivery causes substantially uniform thermal effects in all layers of the trabecular meshwork.    
     
     
         6 . The method of  claim 5  wherein the laser emitter is carried in a contact surface of a thermally conductive material having a surface area greater that about 20 mm 2  thereby conducting heat away from surface sclera layers.  
     
     
         7 . The method of  claim 5  further comprising the steps of sensing the temperature of the sclera overlying the trabecular meshwork with at least one sensor carried within the working face to provide a signal and modulating the laser energy delivery in response to the signal.  
     
     
         8 . A method for delivering energy to a patient's trabecular meshwork to treat glaucoma, comprising the steps of: 
 (a) placing a laser emitter in contact with a patient's eye wherein the axis of laser beam propagation is aligned with the trabecular meshwork;    (b) delivering laser energy from the emitter at a selected wavelength; and    (c) modulating the power level, pulse duration and pulse intervals of the laser energy to maintain the temperature of the trabecular meshwork at less than about 60° C.;    (d) wherein said laser energy delivery causes substantially uniform thermal effects in all layers of the trabecular meshwork.