Experimental Study Of Different Treatment Parameters For The Efficacy Of Reducing IOP Of Transscleral Cyclophotocoagulation Using A Diode Laser

Objective To observe the effect of reducing intraocular pressure (IOP), complications and pathological change of rabbits'eyes after transscleral cyclophotocoagulation with diode laser of different total energy of the laser shot, and compare the efficacy of two treatment protocols. So provide the reference for selecting laser parameter of cyclophotocoagulation curing glaucoma.Methods 15 healthy adult pigment rabbits were chosen and divided into five groups of lower total energy group(group1 and group2), higher total energy group(group3 and group 4), control group. 810nm diode laser transsclerand cyclophotocoagulation was performed in the pigment rabbits of the former four groups. The exposure time of all the group was 2 seconds. In group1 the output was less than 500mw and the numbers of laser pulse applications was 24. In group2 the output was 700mw and the numbers was 12. In group3 the power of laser was 700mw and the numbers was 36. In group4 the output was more than 900mw and the numbers was 24. Cyclophotocoagulation was not performed on control group. The change of the intraocular and complications were recorded and all the rabbits' eyes underwent pathological examination after four weeks.Results The comparison of the reduced IOP of higher total energy group and lower total energy group was statistically significant (P<0.05). The higher total energy group had more severelly destroyed ciliary body and more complications. The comparison of the descended IOP of group1 and group2 was not statistically significant (P>0.05). The pathological change of rabbits'ciliary body and the incidence rate of complications of the two group was the same. The comparison of the descended IOP of group3 and group4 was not statistically significant (P>0.05). The pathological change of the two group was the same. But group3 had more complications.Conclusions Higher total energy induced lower IOP, more severelly destroyed ciliary body and more complications. The efficacy of reducing IOP of the"lower power, more numbers"group and the"higher power, less numbers"group was not difference. But when the total energy was high, the"lower power, more numbers"group had more incidence rate of complications. So we should be cautious to perform Cyclophotocoagulation with lower power and more numbers of laser.