Evaluation Of Prognostic Factors Of Idiopathic Macular Hole Surgery By Optical Coherence Tomography Angiography

Objective: To analyze the prognostic factors of idiopathic macular hole(IMH)treated by vitrectomy combined with aseptic air filling by optical coherence tomography(OCT)and optical coherence tomography angiography(OCTA).Methods: In this study,14 patients with unilateral IMH Gass stage IV were studied retrospectively.From June 2017 to October 2018,14 eyes of 14 patients with IMH were diagnosed in the Ophthalmology clinic of the First Hospital of China Medical University.All patients were treated with cataract extraction combined with vitrectomy and aseptic gas filling.Before the operation,all patients’ eyes best corrected visual acuity(BCVA)was measured by the International Standard Visual acuity scale,the intraocular pressure(IOP)was measured by tonometer(non-standard vision gauge),the fundus was examined by indirect ophthalmoscope,OCT and OCTA after mydriasis.The basal base diameter(BD),minimum diameter(MD),edge height(H)and both ends of the pore diameter of IMH were quantitatively measured by OCT,and calculate the tractional hole index(THI)=H/MD,macular hole index(MHI)= H/BD and diameter hole index(DHI)= MD/BD;using OCTA to evaluate the foveal avascular zone(FAZ)area,vascular density(VD)and the area of IMH of macular fovea at the level of the superficial retinal capillary plexus(SCP)and deep retinal capillary plexus(DCP).All patients were followed up for 3months after operation,measuring intraocular pressure(IOP)and BCVA.Perfoeming fundus examination of indirect ophthalmoscope,measuring the FAZ area and VD of SCP and DCP by OCTA and central foveal thickness(CFT)by OCT.The changes of BCVA,the FAZ area and VD of SCP and DCP before and after treatment were analyzed and compared,and the LogMAR BCVA was analyzed with BD,MD,H,the two ends of hole diameter,THI,MHI,DHI before the operation and CFT,the FAZ area and VD of SCP and DCP after operation.Results: After averange 91(78-131)days follow-up,all 14 patients underwent three-incision 20 G vitrectomy combined with internal limiting membrane stripping and sterile air filling.The best corrected visual acuity(LogMAR BCVA)was 1.179±0.681 at baseline,and after 3-month follow-up,the post-operative LogMAR BCVA was increasedto 0.729 ± 0.249(P = 0.030).The FAZ area of the SCP decraesed from 0.415 ±0.146mm2 at baseline to 0.247±0.110mm2 after 3 months(P<0.001),the change value was 0.169±0.087mm2,which was significantly larger than the area of IMH of preoperative SCP(0.117 ±0.066mm2,Z=-3.296,P=0.001);the FAZ area of DCP decreased from 0.433±0.255mm2 at baseline to 0.175±0.103mm2 after 3 months(P<0.001),with a change of 0.258 ±0.196mm2,significantly larger than the area of IMH of preoperative DCP(0.104±0.064mm2,Z=-3.296,P=0.001).The VD of SCP decreased from 0.301±0.074 at baseline to 0.211 ±0.054 after 3 months(P<0.001),and the change value was 0.090±0.050;The VD of DCP decreased from 0.277±0.055 at baseline to0.224 ±0.054 after 3 months(P =0.006),with a change of 0.053±0.061.There was a positive correlation between postoperative LogMAR BCVA and preoperative BD(r=0.752,P=0.002),and a positive correlation between postoperative LogMAR BCVA and preoperative MD(r=0.661,P=0.010).There was a positive correlation between LogMAR BCVA and the diameter of both ends of the foramen before operation(r=0.681,P=0.007),and a negative correlation between postoperative LogMAR BCVA and preoperative MHI(r=0.723,P=0.004).There was no significant correlation between postoperative LogMAR BCVA and preoperative H,THI,DHI(r=0.191,P=0.512;r=-0.384,P=0.175;r=0.050,P=0.866).There was no significant correlation between postoperative LogMAR BCVA and the FAZ area and VD of SCP and DCP and CFT after operation(r=-0.070,P=0.813;r=0.398,P=0.158;r=-0.267,P=0.357;r=-0.290,P=0.315;r=0.095,P=0.746).Conclusion: After 20 G vitrectomy and aseptic air filling,the FAZ area of SCP and DCP decreased,and the difference of FAZ area of SCP and DCP before and after operation was larger than the area of IMH of SCP and DCP before operation.The results showed that the central fossa tissue showed concentric movement after operation.The ratio of VD of SCP and DCP after operation was lower than that before operation,which indicated that the vascular network of SCP and DCP might be damaged by stress of vitreous traction and could not be recovered.Postoperative BCVA was highly correlated with BD,MD,both ends of the hole and MHI before operation.