| Objective:To investigated the effect of pan-retinal photocoagulation (PRP) with supra scan laser and grid laser photocoagulation with subthreshold micropulse diode laser of supra scan laser on the ischemic central retinal vein occlusion (CRVO) with macular edema (ME) by multifocal electroretinogram (mfERG) and optical coherence tomography (OCT), to analyze the changes of macular function and structure after laser photocoagulation. It is expected to provide clinical evidence for objectively evaluating the effect of laser photocoagulation with supra scan laser.Methods:1.90eyes of90patients who were diagnosed as ischemic CRVO with ME were recruited and divided into three groups, control group, test group A and test group B, there were30eyes in each group. Eyes in the control group were treated with PRP by krypton yellow multiple wavelength laser, the test group A were treated with PRP with PRP by supra scan laser, the test group B were treated with micropulse grid photocoagulation prior to PRP by supra scan laser. The best corrected visual acuity (BCVA), slit-lamp biomicroscope, binocular indirect ophthalmoscope, fluorescence fundus angiography (FFA), OCT and mfERG were examined before treatment.1week,1.5month after treatment, BCVA, OCT and mfERG were examined.2. Statistical method:the data were analyzed by17.0statistical software with methods of independent-sample t test, repeated measure ANOVA, P<0.05as the standard of significant difference in statistic.Results:1. For the control group and the test group A, there was no statistical difference in visual acuity at the1week and1.5month after treatment copared with pre-treatment(P>0.05), there was no statistical difference in both groups among different periods of observation(P>0.05). P1N1amplitude decreased significantly and reached the lowest level at1week post-treatment and recovered at1.5month post-treatment. Compared with group A, P1amplitude had significant decreased in ringl at1week post-treatment(P<0.05), P1N1amplitude had significant decreased in ring1at1.5month post-treatment(P<0.05). P1N1implicit time delayed at1week post-treatment, compared with group A, P1implicit time had significant delayed in ring4(P<0.05), N1implicit time had significant delayed in ringl and quadrant III separately(P<0.05), the recover of P1N1implicit time in test group A at1.5month post-treatment, while there was no sign of recovery in ring1of P1implicit time in the control group at1.5month post-treatment. At the post-treatment, the macular edema in the control group was more significant than test group A and decreased more slowly, but there was no significant difference between two groups (P>0.05). The macular edema decreased in control group at1.5month, but increased than pre-treatment.2. For the test group A and B, there was no statistical difference in visual acuity at the1week and1.5month after treatment copared with pre-treatment, there was no statistical difference in both groups among different periods of observation(P>0.05). P1N1amplitude decreased significantly and reach the lowest level at1week post-treatment, the P1amplitude in ring2, quadrant II and N1amplitude in ring5, quadrant II decreased more significantly in group A than B (P<0.05). The P1N1implicit time had significant delayed in both group A and B, the recover of P1N1implicit time in group B better than group A. Compared with group B, N1implicit time had significant delayed in ring5at1week post-treatment(P<0.05). At the1week after treatment, the macular edema in group A was more significant than pre-treatment, while alleviative in group B, but there was no significant difference between two groups (P>0.05). At1.5month after treatment, the macular edema decreased in both group, there was significant difference compared with pre-treatment in group B (P<0.05), but no significant difference compared with pre-treatmment in group A (P>0.05).Conclusion:As for the eyes with ischemic CRVO and ME, the structure of macula had been changed while the macular function had been damaged for some time; all kinds of response in mfERG had decreased. After laser photocoagulation treatment of different laser instrument, the extent of the macular edema aggravated and the macular function significantly decreased in a short period because of the effects of laser damage, then supra scan laser group seems to recovery in the next observation period, but it was still lower than that of pre-treatment, the thickness of macular still increased compared to pre-treatment.1week post-treatment of those who underwent grid laser photocoagulation with subthreshold micropulse diode laser of supra scan laser prior to PRP with supra scan laser, the extent of macular edema alleviated, the decrease of macular thickness and amelioration of macular function were more significant than those who only underwent PRP. The different therapeutic methods should followed by each patient’s physical sign in clinical application. |
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