Clinical Observation Of The Efficacy Of577nm Multi-point Laser On Diabetic Retinopathy

Objective:To observe the clinical efficacy of the577nm multi-pointscan laser on diabetic retinopathy.Methods:Sixty-one eyes of34Patients with clinically diagnoseddiabetic retinopathy(2002Sydney international ophthalmology meetingsuggested installment standard) sever non-proliferative diabeticretinopathy(NPDR) and proliferative diabetic retinopathy (PDR), wererandomly divided into three groups: group A—577nm multi-point scanlaser(12cases of21eyes)，group B—532nm multi-point scan laser(11cases of20eyes)，and group C—577nm single-point laser(11cases of20eyes), and received the multiple-session pan-retinal photocoagulation. Theenergy of Tso’s III spot, mean time of per session PRP and patients’sfeeling were Recorded, and compared the difference by the statisticalanalysis. Before and3months later of the photocoagulation, The bestcorrected visual acuity (BCVA), fundus fluorescein angiography (FFA) andfundus photography of all cases were evaluated. Results1.BCVA:3months later of PRP, in group A, group B, and group C, theBCVA improved was:4eyes(19.0%),3eyes(15.0%),2eyes(10.0%);un-changed：15eyes(71.4%),14eyes(70.0%),13eyes(65.0%)；anddescended：2eyes(9.5%),3eyes(15.0%),5eyes(25.0%). Comparedthe BCVA in each group, There was no significant difference betweengroup A and group B(P=0.663), group A and group C (P=0.215).2.Change of funds: After3months of PRP, in group A, group B, andgroup C, the significantly efficacy of photocoagulation was:14eyes(66.6%),12eyes(60.0%),10eyes(50.0%); effective：3eyes(14.2%),3eyes(15.0%),4eyes(20.0%)；and invalid：4eyes(19.0%),5eyes(25.0%),6eye(s30.0%), and there was no significant difference betweengroup A and group B(P=0.719), group A and group C (P=0.484).3.Energy: In group A, group B, and group C, the energy of Tso’s IIIspot on retinopathy were:415.67±40.25mW,452.35±45.58mW,230.20±55.8mW. Compared group A with group B, we found that:577nm multi-pointscan laser were less energy(P=0.03)needed,that means, less harms to retina.In the same way, we also concluded that:577nm multi-point scan laserconsumed more energy than577nm traditional single point laser (P<0.001),but the energy density (E=P×t) was still less.4.Mean time: In group A and group C the time of per session of PRPwere:4.52±0.28min,16.52±0.55min. When treated DR with multiple-session PRP, there was significant difference of the mean time ofone session between these two groups(P<0.001), and577nm multi-pointscan laser could save about3/4time compared to577nm single point laser.5.Pain:There were4eyes(19.0%)in group A,5eye(s25.0%)in groupB,10eyes(50.0%) in group C felt pain. There was significant differencebetween group A and group C(P=0.047),577nm multi-point scan laser wasmore comfortable to patients, but no significant difference between group Aand group B(P=0.705)Conclusion:577nm multi-point scan laser can treat diabeticretinopathy effective, and the clinic efficacy is equal to532nm multi-pointscan laser and577nm single-point laser. But577nm multi-point scan lasercosts less energy compared to532nm multi-point laser, which means lessharm to retina. Compared to577nm traditional laser,577nm multi-pointscan laser needs less energy density, can save about3/4time, and is morecomfortable to patients.