Clinical Efficacy Of Applying Allograft Dura Mater With Single Strip Modified Posterior Scleral Reinforcement In The Treatment Of Pathological Myopia

Objective:To investigate the effectiveness and safety of applying allograft dura mater for modified posterior scleral reinforcement to control the progression of pathological myopia,and to provide a basis for posterior scleral reinforcement to control and treat pathological myopia.Methods:Retrospective case series study.A total of 30 patients（33 eyes）with pathological myopia（PM）admitted to Aier Eye Hospital of Nanchang from January 2022 to October 2022 for improved post-scleral reinforcement（PSR）for PM were collected,including 9 males（9 eyes）and 21 females（24 eyes）,aged 10-61 years,with an average age of 35.55±17.26 years.The changes of axis of eye（AL）,best corrected visual acuity（BCVA）,intraocular pressure（IOP）,diopter（SE）,intra-and peripapillary blood density,macular area SCP and DCP blood density and postoperative complications were observed before and 1 week,1 month and 3 months after surgery.SPSS 27.0 was applied for statistical analysis,and the measurement data conformed to normal distribution using one-way ANOVA.Results:1.AL（mm）:the mean AL values of 1w,1m,and 3m in 30 patients（33 eyes）before and after surgery were 28.97±1.18,27.54±1.38,27.67±1.39,and 27.81±1.37.The mean AL values of 1w,1m,and 3m after surgery were significantly lower compared with those before surgery,and the difference was statistically significant（F=7.994,P<0.01）.The postoperative 1m AL increased by 0.13 mm compared with the postoperative 1w,and the postoperative 3m AL increased by 0.14 mm compared with the postoperative 1m.Although the postoperative eye axis still increased,the differences between the postoperative 1w,1m,and 3m AL compared with the preoperative period were statistically significant(t_1w=12.965,P<0.01;t_1m=12.013,P<0.01;t_3m=10.798,P<0.01).2.BCVA（Log MAR visual acuity）:The mean values of BCVA of 30 patients（33eyes）before and after surgery for 1w,1m,and 3m were 0.58±0.33,0.61±0.31,0.57±0.31,and 0.56±0.32.The differences between BCVA of 1w,1m,and 3m after surgery and before surgery were not statistically significant（F=0.128,P>0.05）.3.IOP（mm Hg）:The mean values of IOP in 30 patients（33 eyes）were 15.33±1.88,14.97±2.96,15.09±2.01,and 15.21±2.23 for 1w,1m,and 3m preoperatively and postoperatively.The differences between IOP in 1w,1m,and 3m postoperatively and preoperatively were not statistically significant（F=0.152,P>0.05）.4.Diopter（SE）:The mean SE of 1w,1m and 3m in 30 patients（33 eyes）before and after surgery were（-13.22±3.26）D,（-10.00±2.86）D,（-10.26±2.96）D and（-10.83±2.97）D.The difference in SE of 1w,1m and 3m after surgery compared with that before surgery was statistically significant（F=7.834,P<0.01）.Postoperative 1m increased by 0.26 D compared with postoperative 1w,and postoperative 3m increased by 0.57 D compared with postoperative 1m.Although postoperative SE still increased,the differences between postoperative 1w,1m,and 3m SE compared with preoperative were statistically significant(t_1w=-11.046,P<0.01;t_1m=-10.986,P<0.01;t_3m=-8.780,P<0.01).5.Blood flow density in the optic disc area:the blood flow density in the optic disc in 30 patients（33 eyes）was（53.20±3.42）%,（53.03±3.77）%,（52.52±3.71）%,（53.36±3.27）%for 1w,1m,and 3m preoperatively and postoperatively,and the blood flow density around the optic disc in 1w,1m,and 3m preoperatively and postoper-atively was(46.90±（2.46）%,（46.47±2.45）%,（46.90±2.91）%,（47.29±2.44）%.The postoperative intra-and peri-optic disc flow densities at 1w,1m,and 3m were not statistically significant compared with the preoperative ones(F _{intra-optic disc}=0.349,P>0.05;F _{peri-optic disc}=0.561,P>0.05).6.Macular flow density:The preoperative and postoperative macular SCP flow densities of 1w,1m,and 3m in 30 patients（33 eyes）were（36.22±1.44）%,（44.24±1.38）%,（43.95±1.32）%and（43.61±1.30）%,the preoperative and postoperative macular DCP flow densities of 1w,1m,and 3m were（31.66±2.36）%,（40.93±1.84）%,（40.74±2.06）%,（40.28±1.94）%.The differences in postoperative macular SCP and macular DCP blood density were statistically significant compared with those before surgery(F_{macular SCP}=266.357,P<0.01;F_{macular DCP}=157.435,P<0.01).Postoperative macular area SCP and DCP blood flow density increased significantly compared with preoperative,and postoperative 1w,1m,and 3m macular area SCP blood flow density increased by 8.02%,7.73%,and 7.39%,respectively,compared with preoperative,and postoperative 1w,1m,and 3m macular area DCP blood flow density increased by 9.27%,9.08%,and 8.62%,respectively,compared with preoperative,although postoperative 1m and 3m macular area SCP and DCP flow density decreased in the postoperative 1m and 3m macula compared with the preoperative 1w,but the differences were statistically significant in the postoperative1w,1m and 3m macula SCP and DCP flow density compared with the preoperative1w（t1w macula SCP=-27.259,P<0.01;t1m macula SCP=-27.236,P<0.01;t3m macula SCP=-26.135,P<0.01,t1w macular area DCP=-16.958,P<0.01;t1m macular area DCP=-16.513,P<0.01;t3m macular area DCP=-15.858,P<0.01）.7.All patients developed conjunctival congestion and edema after surgery,but the symptoms were significantly relieved after 2 weeks;4 patients（4 eyes）had mild visual distortion after surgery,and the visual distortion was relieved in 3 months after surgery;3 patients had postoperative IOP≥30 mm Hg,and 1 patient had IOP between25-29mm Hg,and the IOP was reduced to normal within 1 week after giving IOP-lowering drops.No serious complications occurred in all patients in the short term after surgery.Conclusions:1.The application of allograft dura mater for modified PSR for PM is safe and effective in delaying the growth of the eye axis and diopter in the short term.2.The macular area SCP and DCP blood flow density increased significantly in the short term after PSR compared with the preoperative period,suggesting that the macular area retinal blood circulation can be improved.