Comparison between laser multi-point scanning and single-point multiple scanning for the treatment of non-proliferative diabetic retinopathy

AIM: To compare the curative effects between laser multi-point scanning and single-point multiple scanning for the treatment of non-proliferative diabetic retinopathy. METHODS: Fifty patients with non-proliferative diabetic retinopathy from January 2010 to January 2014 in our hospital were selected for the study, and were divided into two groups, the control group and the observation group, using a random number table. Twenty-five patients (43 eyes) in the observation group completed panretinal photocoagulation (PRP) therapy once by 577nm laser multi-point scanning. Twenty-five patients (41 eyes) in the control group completed PRP therapy by the single-point multiple scanning. The differences of average threshold sensitivity of visual field, F-ERG a/b wave amplitude, the clinical effective rates, the laser energy, the number of laser spot and the energy density between the two groups at various time points were compared. RESULTS: At 1d after the treatments, average threshold sensitivity of visual field was lower than those at 1d before treament, and the difference was statistically significant (t=2.421, P=0.017). The differences of average threshold sensitivity between the two groups at 1d before treatments, at 1d, 1, 2, 6, 12mo after treatments, were not statistically significant (P>0.05). The F-ERG a wave amplitude of both groups at 1d after treatments were lower than those of 1d before treatments, and the difference was statistically significant (t=2.319, P=0.025). There were no differences of the F-ERG b wave amplitude between both groups at 1d before treatments and at 1d, 1, 2, 6, 12mo after treatments (P>0.05). The F-ERG b wave amplitude of both groups at 1d after treatments were lower than those at 1d before treatments, and the difference was statistically significant (t=2.276, P=0.031). There were no differences between the two groups in terms of clinical effective rates and the number of laser spot (P>0.05). Laser energy used in the observation group was higher than that in the control group, the energy density was lower than that in the control group. The differences on the two items were statistically significant (P <0.05). CONCLUSION: There is no significant difference on clinical efficacy between laser multi-point scanning and single-point multiple scanning of PRP therapy. But the energy density of multi-point scanning mode is lower, and the damage made by this mode is less.