Methods and apparatus for presbyopia correction using ultraviolet and infrared lasers

Abstract

Presbyopia is treated by a system using various lasers to remove a portion of the scleral tissue and increase the accommodation of the presbyopic patient's eye. Stable accommodation is achieved by the filling of the sub-conjunctiva tissue to the laser-ablated scleral areas. The proposed laser wavelength ranges from ultraviolet to infrared of (0.15-0.36) microns, (0.5-1.4) microns and (0.9-3.2) microns. Both scanning and fiber delivered systems are proposed to generate the ablation patterns. Laser ablation of the sclera may be conducted with or without opening the conjunctiva layer.

1 . A laser beam ophthalmic surgery method for treating a presbyopic patient, the method comprising: 
 opening a subconjunctiva tissue of an eye of the patient; and    forming at least one gap in a scleral tissue of the eye by removing a portion of the scleral tissue of the eye with laser ablation to a depth between approximately 60% and approximately 90% of the sclera tissue thickness, wherein the laser is a cold laser so as to allow the patient's subconjunctiva tissue to fill in the at least one gap.    
     
     
         2 . The method of  claim 1 , wherein no implant is implanted into the at least one gap.  
     
     
         3 . The method of  claim 1 , wherein the subconjunctiva tissue filled into the at least one gap has a greater flexibility than the scleral tissue.  
     
     
         4 . The method of  claim 1 , further comprising performing a measurement of the patient's scleral thickness.  
     
     
         5 . The method of  claim 1 , further comprising performing a measurement of the patient's scleral thickness, wherein the measurement comprises observing a color change of the scleral tissue.  
     
     
         6 . The method of  claim 1 , wherein forming the at least one gap comprises using a cold laser having a wavelength between about 0.15 μm and about 0.36 μm, or between about 2.6 μm and about 3.2 μm.  
     
     
         7 . The method of  claim 1 , wherein: 
 forming the at least one gap comprises forming at least 3 radial lines around the cornea outside the limbus;    each radial line has a width between about 0.1 mm and about 1.0 mm; and    each radial line has a length between about 2.0 mm and about 5.0 mm.    
     
     
         8 . The method of  claim 1 , wherein the at least one gap is formed in an area outside the limbus and between two circles having a diameter of about 10 mm and about 18 mm.  
     
     
         9 . The method of  claim 1 , wherein forming the at least one gap comprises forming at least 3 curved lines around the cornea outside the limbus.  
     
     
         10 . The method of  claim 1 , wherein: 
 forming the at least one gap comprises forming a dotted ring pattern around the cornea outside the limbus; and    each dot has a diameter between about 0.1 mm and about 2.0 mm.    
     
     
         11 . The method of  claim 1 , wherein the at least one gap comprises a pattern generated by a device selected from the group consisting of a scanning mechanism, a fiber-coupled device, and a translation device.  
     
     
         12 . The method of  claim 1 , wherein the at least one gap comprises a pattern generated by a mask that is not transparent to the laser.  
     
     
         13 . A method of treating a presbyopic eye using a laser beam, the method comprising: 
 using the laser beam to form a gap in scleral tissue of the presbyopic eye, the gap having a depth of between about 500 μm and about 700 μm;    allowing conjunctiva tissue of the eye to fill the gap, such that accommodation of the presbyopic eye increases via movement of ciliary body and zonular fiber connected to the lens of the presbyopic eye.    
     
     
         14 . The method of  claim 13 , wherein allowing conjunctiva tissue of the eye to fill the gap comprises not implanting an implant into the gap.  
     
     
         15 . The method of  claim 13 , further comprising measuring a thickness of the scleral tissue before allowing the conjunctiva tissue to fill the gap.  
     
     
         16 . The method of  claim 13 , further comprising opening conjunctiva tissue of the eye before using the laser beam to form a gap in the scleral tissue.  
     
     
         17 . The method of  claim 13 , wherein the gap is formed in the scleral tissue without opening the conjunctiva.  
     
     
         18 . The method of  claim 13 , wherein the laser beam is a short pulse solid state laser having a wavelength between about 0.5 μm and about 1.4 μm, and having a pulse width of between about one femtosecond and about one nanosecond.  
     
     
         19 . The method of  claim 13 , wherein the laser beam is focused to a spot size between about 1 μm and about 500 μm to selectively remove scleral tissue underneath the conjunctiva layer.  
     
     
         20 . The method of  claim 13 , wherein the laser is a cold laser.  
     
     
         21 . The method of  claim 13 , wherein the conjunctiva tissue filled into the gap has a greater flexibility than the scleral tissue.