Modified Trabeculectomy Versus Glaucoma Drainage Implant Surgery-a Retrospective Comparative Study For Refractory Glaucoma Treatment

Purpose.To observe and compare the efficacy of modified trabeculectomy,Ahmed drainage valve implantation(AGV)and EX-PRESS glaucoma shunt in the treatment of refractory glaucoma.Methods.The retrospective study included 76 eyes of 73 patients who were suffered from refractory glaucoma and treated with modified trabeculectomy,AGV and Ex-PRESS glaucoma shunt in our hospital from October 2012 to September 2020.The modified trabeculectomy was performed in 38 eyes of 36 patients.The AVG was performed in 20 eyes of 19 patients,and the 18 eyes of 18 patients were treated with EX-PRESS glaucoma shunt.The best-corrected visual acuity(BCVA),intraocular pressure(IOP),the postoperative anti-glaucoma medications,filter bubble morphology,anterior chamber depth(ACD),successful rate,and postoperative complications were recorded and statistically analyzed preoperative and 1d,1w,1mon,3mon,6mon and the end follow-up after operation.Results.The mean follow-up time of the modified trabeculectomy,AGV and EX-PRESS group was(29.89±24.80),(56.30±39.42),(26.00±12.25)months,respectively.In modified trabeculectomy group,BCVA was 2.15±0.82 Log MAR before operation;BCVA was 2.00±0.81 Log MAR at 6 month after surgery.In AVG group,BCVA was 2.07±0.21 Log MAR before operation;BCVA was 2.02±0.21 Log MAR at 6 month.In EX-PRESS group,BCVA was 1.51±0.30 Log MAR before operation;BCVA was 1.18±0.31 Log MAR at 6 month.There was no significant difference in BCVA among the three group(P=0.08;0.25;0.12).Compared to preoperative BCVA,the postoperative BCVA of the three groups had no statistical significance(the modified trabeculectomy group P=0.08;AGV group P=0.25;EX-PRESS shunt group P=0.12).IOP was decreased from 47.37 ± 17.55 to 13.89 ±9.53 mm Hg in modified trabeculectomy group,and from 49.50 ± 15.63 to 12.35 ±2.03 mm Hg in AGV group,and from 46.78±16.54 to 13.22±3.72 mm Hg in EX-PRESS group.The IOP among the three group after operation was significantly decreased compared with that before operation(P<0.001).The extent of the decrease in IOP in the three group were 63.68±31.68%,70.62±16.61% and 68.83±11.33%.The extent of the decrease in IOP in AGV group was slightly higher than those of modified trabeculectomy and EXPRESS groups,and the degree of IOP decline was significantly correlated with preoperative IOP.The postoperative IOP of the three groups was significantly lower than that of preoperative IOP(P<0.001),and the degree of IOP decline was significantly correlated with preoperative IOP.The number of anti-glaucoma medications was from 3.66±1.24 to0.29±0.89 in modified trabeculectomy group,and from 3.75±0.91 to 0.15±0.67 in AGV group,and from 4.22±0.67 to 0.33±1.00 in EX-PRESS group.The number of antiglaucoma medications after surgery decreased significantly compared to that before surgery in the three groups(P<0.05).The postoperative ACD of the AGV group was deeper than that before operation(P=0.007),while,there was no significant difference in modified trabeculectomy and EX-PRESS groups(P=0.222;0.422).In 6 month after operation,there was no significant difference in the total success rates in modified trabeculectomy,AGV and EX-PRESS groups(97.37%,100% and 100%,P=1.000).In the last follow-up,there was no significant difference in the total success rates in modified trabeculectomy,AGV and EX-PRESS groups(94.73%,95% and 88.89%,P=0.705).However,the total success rates in modified trabeculectomy and AGV groups were slightly higher than that of EXPRESS group.The incidence rates of postoperative complications had no statistically significant differences in modified trabeculectomy,AGV and EX-PRESS groups(34.21%,35% and 44.44%,P=0.745),while,the postoperative complications of modified trabeculectomy and AGV groups were slightly lower than that of the EX-PRESS group.There was no significant difference in filter bubble morphology after operation among the three groups(P=0.347).Conclusion.The efficacy of the modified trabeculectomy was similar to that of the AGV and Ex-PRESS glaucoma shunt for the treatment of refractory glaucoma.They could effectively reduce IOP and decrease the number of postoperative anti-glaucoma medications in refractory glaucoma.There was no significant difference in the success rate and the postoperative complications among the three groups.However,the success rates of modified trabeculectomy and AGV were slightly higher than that of EX-PRESS glaucoma shunt in the last follow-up,and the complications of them were slightly less than those of the EXPRESS glaucoma shunt.