Popis: |
Nanosecond pulses from CO2 TEA lasers, (A= 10,600nm,T = 3ns, 4Ons and 200ns), HF lasers (X= 2,744nm,1'= 300ns) and excimer lasers (N= 193nm,T= 15ns) were focussed (either through cylindrical quartz lens or 0.001" thick Beryllium-copper mask etched with slits of various widths) onto the corneas of enucleated dog eyes. Pulse energies were measured with a pyroelectric or disc calorimeter, placed behind the mask. The mask unit area and the number of pulses were varied to determine energy parameters required for ablation of different depths of corneal tissue. Ultrastructural studies of corneal incisions made with knife were compared with those made by laser pulses. |