Effect Of Phacotrabeculectomy On The Change Of Peripapillary Vessel Density

ObjectiveTo investigate the differences of vascular microcirculation at optic disc in acute primary angle closure glaucoma(a PACG)and normal eyes.To analyze the correlation and diagnostic ability of different glaucoma parameters.To observe the changes of microcirculation in acute angle closure glaucoma patients after phacotrabeculectomy using optical coherence tomography angiography(OCTA).MethodsSubjects were divided into two groups.The glaucoma group included 30 patients(30 eyes)who were diagnosed with a PACG in chronic stage and underwent phacotrabeculectomy,while the control group included 32 normal(32 eyes).A commercially available OCTA device was performed in both groups to get the vessel density(VD)of optic disc and retinal nerve fiber layer(RNFL)thickness.VD and RNFL thickness was measured preoperative,1-week,1-month and 3-month postoperatively in the glaucoma group,at the same time,the other data such as intraocular pressure(IOP)and mean deviation(MD)were collected for analysis.The relationship among preoperative VD,RNFL thickness and MD in glaucoma group was analyzed.To compare the change of VD and the change of IOP in a PACG who suffered the surgery.ResultsThe whole and peripapillary vessel density(PvD)of patients with a PACG were significantly lower than those of the control group(44.61±5.26% vs.49.98±2.24%;47.17±5.75% vs.52.73±2.14%,P<0.001).RNFL thickness was also significantly lower than that of the control group(97.83±12.73μm vs.115.31±10.17μm,P<0.001),and MD was significantly lower than that of the control group(-9.68±7.30 vs.-2.48±1.63,P<0.001).There was a significant positive correlation between PvD and RNFL thickness(r=0.773,P<0.001)as well as MD(r=0.768,P<0.001)in the glaucoma group,while a significant negative correla tion between PvD and IOP(r=-0.752,P<0.001).The diagnostic accuracy of visual field MD was the highest,followed by RNFL thickness,the whole VD and PvD.The preoperative IOP in the glaucoma group was significantly higher than 1-week postoperatively(31.10±10.10 mm Hg vs.13.37±2.21 mm Hg,P<0.001).There was no significant difference in the mean IOP of 1-week,1-month and 3-month postoperatively(13.37 ±2.21 mm Hg;12.33±2.77 mm Hg;12.13±2.33 mm Hg,all P>0.05).The postoperative whole VD and PvD slightly decreased within 1 week,and then increased gradually.The whole VD and PvD was significantly improved at 3 months postoperatively compared with those before surgery(P<0.001).The peripapillary RNFL thickness increased within 1 week after surgery,then recovered to the preoperative level 3 months after surgery,with no statistically significant difference(P>0.05).ConclusionsPvD,RNFL thickness and MD of a PACG in chronic stage were significantly lower than those in normal.There was an obvious correlation between PvD,RNFL thickness,MD and IOP.The IOP of a PACG decreased significantly after phacotrabeculectomy,and remained stable for 3 months postoperatively.PvD improved obviously compared with that pre the operation,but the change of RNFL thickness was not significant.