The Study On The Mechanism Of Postoperative Recovery Of Idiopathic Macular Hole

Objective:1.To dynamic observe the healing process of pars plans vitrectomy in the treatment of idiopathic macular hole,combined with internal limiting membrane flap technique and air tamponade by SD-OCT.2.To study healing mechanism of retinal tears in SD rats after Nd:YAG laser.3.The mechanism of healing and repair was discussed through animal models.Methods:Retrospective analysis of the study.1.A total of 12 eyes of 12 patients with IMH that had received PPV with inverted ILM flap technique during April 2017 to October 2019from the three two zero one hospital,the patients were required to maintain face-down positioning for 3⁷ days after operation,and accepted follow-up visit for 6 months at least.All the patients included in this study were examined by BCVA,IOP,slit lamp+front mirror and SD-OCT.2.20 male SD rats underwent Nd:YAG laser to construct retinal tears model.The healing process of retinal tears was observed by SD-OCT scanning in 4¹2days,and H&E staining were collected in the day 1¹2,in add to,the expression of Müller cell marker GFAP in the retina of SD rats was detected by immunohistochemistry and immunofluorescence staining.Results:1.A total of 12 eyes met the inclusion criteria and 12 eyes were closed.The hole closure rate is 100%.The postoperative BCVA?LogMAR?at 1 month,3 month and 6month were 1.05±0.24,0.98±0.15,0.86±0.19,0.81±0.23 respectively.The BCVA was significantly improved compared with preoperation,at 3rd month and 6th month,?p₂<0.05,p₃<0.05?.The main type of healing was U-shaped,accounting for 66.7%of all cases,4 cases of V-shaped healing,accounting for 33.3%of the total cases,and no W-shaped healing cases.SD-OCT images showed‘hyper-reflective'during the repairing process in ten cases.2.SD-OCT images observed retinal tears in the third day,and showed that‘hyperreflective'mass and retinal proliferative membrane appeared in SD rats in 5th after Nd:YAG laser operation.The structure of each layer of retina became clear and‘hyper-reflective'mass disappeared gradually in the 7th day,and the retinal tears basically healed on the 10th day.H&E staining showed that on the first day after Nd:YAG laser operation,the structure of each layer of retina was broken,a small number of deeply stained nuclei were seen,the loose reticular structure was not connected completely,and cells were disorder arrangement and retinal hole formation.H&E staining showed that the structure of each layer of retina was broken,there were irregular and disorder arrangement cell,mixing with red blood cells,exfoliated necrotic tissue and irregularly broken and lightly stained nuclei appeared in 3rd days after Nd:YAG laser operation.There is no obvious necrotic tissue in the retinal hole.It can be seen that there are a large number of cell processes,nuclear light staining cells filled,the nerve fiber layer is continuous,showing a thick loose reticular structure,and the fibrous membrane can be seen in front of the retina in the 5th day postoperatively.the structural boundary of each layer of the retina was gradually clear,which was slightly thinner than that of the normal retina,there were cell processes and nuclear light-stained cells,the cells gradually returned to polarity,and the thickened fibrous membrane could be seen in front of the the tear in the 7th day postoperatively.The retinal structure was basically normal in 10th day.Immunohistochemical staining showed that GFAP positive cells could be seen in the retinal nerve fiber layer.GFAP positive cells in the tears proliferated around the cells and proliferated into the cell mass.Immunofluorescence staining showed that a large number of GFAP positive cells formed a mass at the healing of the tear,and a small number of GFAP positive cells were found on the surface of the retina.The mean fluorescence intensity is 50.24±0.03.Conclusion:The PPV with ILM flap technique can effectively close the macular hole,and the hyper-reflective site in SD-OCT images during the postoperative healing process.The retinal tears model of SD rats was successfully constructed by Nd:YAG laser.During retinal holes healing in SD rats,SD-OCT detected a‘hyper-reflective'mass similar to that during macular hole healing.The‘hyper-reflective'mass was confirmed to be the proliferation of Müller cells by H&E staining,immunohistochemical staining and immunofluorescence staining.