Trabeculectomy With MMC or With Amniotic Membrane Transplant
Trabeculectomy With MMC or With Amniotic Membrane Transplant
Trabeculectomy augmented with antimetabolites is the standard primary treatment for glaucoma in the developing world. Marey et al in their study compared trabeculectomy augmented with MMC versus Ologen implant in an Egyptian population. At the end of 12 months postoperatively, the mean IOP was statistically lower in both groups, with complete success in all patients.
Singh et al, in a short-term comparative study of 81 patients undergoing trabeculectomy with MMC or 5-FU in a Ghana population, reported a higher success rate with respect to the final IOP level in the MMC group. In a subsequent retrospective study with 3 years or longer follow-up, they reported that a significantly higher proportion of eyes with MMC augmentation achieved an IOP <21 mm Hg without medications. Similar results were reported with Anand and Dawda in another retrospective comparative study involving 132 eyes in West Africa that had trabeculectomy with MMC or 5-FU. Over a follow-up period of >3 years, significantly higher proportion of patients achieved an IOP<21 mm Hg without medications, and the postoperative IOP was significantly lower in the MMC group at all follow-up visits except between 30 and 35 months.
Our study in a similar population confirms their observations. MMC-augmented trabeculectomy was successful in lowering the IOP in all patients after 24 months of follow-up. All patients achieved an IOP of <21 mm Hg (final mean IOP was 15.9±3.9 mm Hg). However, a few patients (19.23%) required a maximum of 2 antiglaucoma medications to maintain their IOP control postoperatively.
Since Fujishima et al in 1998 described the first use of AMT in trabeculectomy with success, the procedure has been used by many investigators with favorable outcome.
Sheha and his colleagues have studied the use of AMT in trabeculectomy with MMC (study eyes) compared with trabeculectomy with MMC alone (control eyes), in a prospective, randomized study including 37 eyes with refractory glaucoma. Complete success (IOP<22 without glaucoma medications) was seen in 12/15 (80.0%) study eyes and 6/15 (40%) control eyes at 12 months after surgery. They have concluded that, trabeculectomy combined with MMC and AMT compared with trabeculectomy with MMC alone has higher success rates, lower postoperative mean IOPs, and less complication rate.
In another study by Jiang and colleagues, the use of AMT with trabeculectomy in 49 eyes achieved a quality success rate of 93.9% (46/49) at the end of 24 months after the operation with no significant complications. The mean IOP before the operation and 24 months after the operation were 34.84±11.02 and 18.24±1.34 mm Hg, respectively (P=0.000).
Mahdy and others have studied the use of AMT and MMC in trabeculectomy for pediatric glaucoma. Thirty eyes with pediatric glaucoma were divided into 2 groups (15 eyes each). One group had trabeculectomy with MMC and AMT, and the other had trabeculectomy with MMC alone. After 18 months of follow-up, the mean IOP was significantly decreased to 15.0±1.0 and 17.2±2.9 mm Hg, respectively. There was no significant difference in the IOP-lowering effect of the 2 procedures. However, patients who had undergone trabeculectomy with AMT did not have complications such as inflammation, choroidal detachment, or toxic keratopathy as noted in the other group.
Similar results were reported by other investigators; however, most of these trials were nonrandomized.
Anand and colleagues studied the safety and efficacy of AMT in glaucoma drainage device surgery over a mean postoperative follow-up of 22.0±3.0 months and found that the translucency of amniotic membrane graft enabled good visualization of the occluding suture when performing laser suture lysis. Sequential anterior segment optical coherence tomography showed stable AMT thickness with a change from low to moderate reflectivity in the subconjunctival-graft bilayer and concluded that AMT offers good tectonic support and allows direct visualization of the underlying tube.
In another recent prospective randomized trial by Stavrakas and his colleagues, they assessed the efficacy of AMT in trabeculectomy over a follow-up period of 24 months in 59 eyes. However, they did not use antimetabolites in the control group. IOP postoperative reduction was 8 mm Hg for the AMT group versus 6 mm Hg in the non-AMT group (P=0.276). The reduction of IOP was greater in the AMT group throughout the 24 months of follow-up, but the difference was not statistically significant at any point.
In this prospective randomized trial, we assigned patients to receive trabeculectomy with AMT or MMC. At the first postoperative day the IOP level dropped to 7.1±2.3 mm Hg in the MMC group and to 6.6±1.8 mm Hg in the AMT group compared with preoperative values of 25.6±1.6 and 25.1±2.1 mm Hg, respectively. There was no statistically significant difference between the 2 groups throughout the postoperative period. By the end of the 24-month postoperative period, the IOP level was 15.9±3.9 mm Hg in the MMC group and 15.7±3.3 mm Hg in the AMT group (P=0.113).
There was no significant complication as inflammation, choroidal detachment, or toxic keratopathy with the use of AMT, and there was no indication for the use of antimetabolite subconjunctival injection in the postoperative period. The bleb was functioning well in the follow-up period in most of the cases.
In conclusion, AMT exhibits potential as an alternative to MMC in trabeculectomy surgery. Over 24 months of follow-up, the use of AMT with trabeculectomy was safe and effective with an IOP-lowering effect comparable to that achieved with the use of MMC, and a reduced rate of postoperative complication.
Discussion
Trabeculectomy augmented with antimetabolites is the standard primary treatment for glaucoma in the developing world. Marey et al in their study compared trabeculectomy augmented with MMC versus Ologen implant in an Egyptian population. At the end of 12 months postoperatively, the mean IOP was statistically lower in both groups, with complete success in all patients.
Singh et al, in a short-term comparative study of 81 patients undergoing trabeculectomy with MMC or 5-FU in a Ghana population, reported a higher success rate with respect to the final IOP level in the MMC group. In a subsequent retrospective study with 3 years or longer follow-up, they reported that a significantly higher proportion of eyes with MMC augmentation achieved an IOP <21 mm Hg without medications. Similar results were reported with Anand and Dawda in another retrospective comparative study involving 132 eyes in West Africa that had trabeculectomy with MMC or 5-FU. Over a follow-up period of >3 years, significantly higher proportion of patients achieved an IOP<21 mm Hg without medications, and the postoperative IOP was significantly lower in the MMC group at all follow-up visits except between 30 and 35 months.
Our study in a similar population confirms their observations. MMC-augmented trabeculectomy was successful in lowering the IOP in all patients after 24 months of follow-up. All patients achieved an IOP of <21 mm Hg (final mean IOP was 15.9±3.9 mm Hg). However, a few patients (19.23%) required a maximum of 2 antiglaucoma medications to maintain their IOP control postoperatively.
Since Fujishima et al in 1998 described the first use of AMT in trabeculectomy with success, the procedure has been used by many investigators with favorable outcome.
Sheha and his colleagues have studied the use of AMT in trabeculectomy with MMC (study eyes) compared with trabeculectomy with MMC alone (control eyes), in a prospective, randomized study including 37 eyes with refractory glaucoma. Complete success (IOP<22 without glaucoma medications) was seen in 12/15 (80.0%) study eyes and 6/15 (40%) control eyes at 12 months after surgery. They have concluded that, trabeculectomy combined with MMC and AMT compared with trabeculectomy with MMC alone has higher success rates, lower postoperative mean IOPs, and less complication rate.
In another study by Jiang and colleagues, the use of AMT with trabeculectomy in 49 eyes achieved a quality success rate of 93.9% (46/49) at the end of 24 months after the operation with no significant complications. The mean IOP before the operation and 24 months after the operation were 34.84±11.02 and 18.24±1.34 mm Hg, respectively (P=0.000).
Mahdy and others have studied the use of AMT and MMC in trabeculectomy for pediatric glaucoma. Thirty eyes with pediatric glaucoma were divided into 2 groups (15 eyes each). One group had trabeculectomy with MMC and AMT, and the other had trabeculectomy with MMC alone. After 18 months of follow-up, the mean IOP was significantly decreased to 15.0±1.0 and 17.2±2.9 mm Hg, respectively. There was no significant difference in the IOP-lowering effect of the 2 procedures. However, patients who had undergone trabeculectomy with AMT did not have complications such as inflammation, choroidal detachment, or toxic keratopathy as noted in the other group.
Similar results were reported by other investigators; however, most of these trials were nonrandomized.
Anand and colleagues studied the safety and efficacy of AMT in glaucoma drainage device surgery over a mean postoperative follow-up of 22.0±3.0 months and found that the translucency of amniotic membrane graft enabled good visualization of the occluding suture when performing laser suture lysis. Sequential anterior segment optical coherence tomography showed stable AMT thickness with a change from low to moderate reflectivity in the subconjunctival-graft bilayer and concluded that AMT offers good tectonic support and allows direct visualization of the underlying tube.
In another recent prospective randomized trial by Stavrakas and his colleagues, they assessed the efficacy of AMT in trabeculectomy over a follow-up period of 24 months in 59 eyes. However, they did not use antimetabolites in the control group. IOP postoperative reduction was 8 mm Hg for the AMT group versus 6 mm Hg in the non-AMT group (P=0.276). The reduction of IOP was greater in the AMT group throughout the 24 months of follow-up, but the difference was not statistically significant at any point.
In this prospective randomized trial, we assigned patients to receive trabeculectomy with AMT or MMC. At the first postoperative day the IOP level dropped to 7.1±2.3 mm Hg in the MMC group and to 6.6±1.8 mm Hg in the AMT group compared with preoperative values of 25.6±1.6 and 25.1±2.1 mm Hg, respectively. There was no statistically significant difference between the 2 groups throughout the postoperative period. By the end of the 24-month postoperative period, the IOP level was 15.9±3.9 mm Hg in the MMC group and 15.7±3.3 mm Hg in the AMT group (P=0.113).
There was no significant complication as inflammation, choroidal detachment, or toxic keratopathy with the use of AMT, and there was no indication for the use of antimetabolite subconjunctival injection in the postoperative period. The bleb was functioning well in the follow-up period in most of the cases.
In conclusion, AMT exhibits potential as an alternative to MMC in trabeculectomy surgery. Over 24 months of follow-up, the use of AMT with trabeculectomy was safe and effective with an IOP-lowering effect comparable to that achieved with the use of MMC, and a reduced rate of postoperative complication.