The Changes Of Macular Morphology And Retinal Blood Flow In Large Diameter Idiopathic Macular Hole After Internal Limiting Membrane Insertion Or Inverted Internal Limiting Membrane Flap Technique

Objective:To observe the changes of macular morphology and blood flow characteristics in patients with large diameter idiopathic macular hole before and after internal limiting membrane insertion or inverted internal limiting membrane flap technique.Methods:37 patients（37 eyes）with large diameter（>600μm）IMH,treated in the ophthalmology department of the first affiliated Hospital of Bengbu Medical College from February 2019 to October 2020,were selected.These patients were divided into two groups randomly:group A（vitrectomy combined with ILM insertion and vitreous cavity disinfected air filling）and group B（vitrectomy combined with ILM flap technique and vitreous cavity disinfected air filling）.The best corrected visual acuity、the defect diameter of external limiting membrane、the defect diameter of ellipsoid zone、the area of foveal avascular zone、vessel density of superficial capillary plexus、vessel density of deep capillary plexus、hole closure morphology were observed before and 1month and 3 months after operation to compared the clinical effect.Result:1.Macular hole closure rate and morphology:19 eyes（95.00%）were closed in Group A.And postoperatively,the foveal configuration was identified as U-shaped in 6 eyes,V-shaped in 12 eyes and W-shaped in 1 eye.In Group B,15 eyes（88.24%）were closed.9 eyes demonstrated U-shaped,6 eyes demonstrated V-shaped.The rate of hole closure had no statistical difference between the two groups（P>0.05）.2.BCVA:As time went on,the BCVA of the two groups changed significantly,and a statistical difference could be seen between the two groups.The change trend of BCVA was different in the two groups,that is,B group had more significant BCVA improvement(F _time=54.231,P _time<0.05,F _interaction=5.538,P _interaction<0.05,F _group=4.408,P _group<0.05).At 1 month postoperatively,the average BCVA（log MAR）of A group was 0.98±0.17.In B group,it was 0.84±0.23.The statistical difference can be seen between the two groups（P<0.05）.The average BCVA of A group was 0.95±0.22,and that of B group was 0.74±0.20 in3 months after operation.There was statistical difference between the two groups（P<0.05）.3.ELM defect ranges:As time went on,ELM defect ranges of the two groups changed significantly.But there was no statistical difference between the two groups(F _time=593.830,P _time<0.05;F _interaction=2.624,P _interaction=0.800;F _group=0.109,P _group=0.743).According to intra-group comparison:differences are both statistically significant at different time（P<0.05）.4.EZ defect ranges:EZ defect ranges in the two groups changed significantly with time,but there was no statistical difference between the two groups(F _time=298.852,P _time<0.05;F _interaction=3.196,P _interaction=0.053;F _group=0.234,P _group=0.632).According to intra-group comparison of EZ defect ranges at different time:differences are both statistically（P<0.05）.5.FAZ area:The FAZ area of the two groups changed significantly with time,but there was no statistical difference between two groups(F _time=108.671,P _time<0.05,F _interaction=0.717,P _interaction=0.495,F _group=0.272,P _group=0.605).According to intra-group comparison:In both two groups,compared between before and after 1 month、before and after 3months,difference was statistically significant（P<0.05）.But no statistical difference can be seen between 1 month and 3 months postoperatively（P>0.05）.6.SVD、DVD:About SVD,no statistical difference can be seen in the two groups before and after operation.And there was no statistical difference between the two groups(F _time=3.033,P _time=0.055,F _interaction=0.051,P _interaction=0.950,F _group=0.980,P _group=0.329).In DVD,before and after operation,there was no statistical difference in the two groups.And there was no statistical difference between the two groups(F _time=1.368,P _time=0.261,F _interaction=1.365,P _interaction=0.262,F _group=1.408,P _group=0.313).There was no statistical difference in SVD and DVD between the two groups both 1moth and 3 mon after operation（P>0.05）.Conclusion:ILM insertion and inverted ILM flap technique are both effective surgical method for large diameter IMH.They can obviously improve the visual acuity and obtain a favorable hole closure rate.But the visual acuity and hole closure morphology after inverted internal limiting membrane flap technique are better than internal limiting membrane insertion.The area of FAZ decreased significantly after internal limiting membrane insertion and inverted internal limiting membrane flap technique,which suggested that the foveal tissue had centripetal movement.But there was no significant change in SVD and DVD.