Comparative safety profile between "modern" trabeculectomy and non-penetrationg deep sclerectomy

To compare the incidence and the severity of short-and medium-term complications following "modern" trabeculectomy (mTRAB) with non-penetrating deep sclerectomy (NPDS).

Comparative retrospective nonrandomized study including 65 eyes (55 patients) (mean age: 68.6 years) with medically uncontrolled glaucoma. mTRAB was performed in 43 eyes, NPDS in 22 eyes. mTRAB was performed according to a slightly modified P.T. Khaw protocol. NPDS procedures were done according to Kozlov's and Mermoud's technique with SKGEL implant in 18/22 eyes. Intraoperative antimetabolites (AMETAB) were given in 25 eyes (58%) in the mTRAB and 17 (77%) in the NPDS (p>0.05).

Mean follow-up was longer in NPDS (10.7+/-5.5 months) than in mTRAB (8.5+/-3.4 months) (p<0.05). Preoperatively, the two groups were comparable in respect of age, type of glaucoma, mean IOP, severity of VF defects and bleb failure risk factors (p>0.05). Peroperatively, mTRAB were uneventful in 86% vs 90% of NPDS. 1st month postop complications occurred in 60.4% in mTRAB and 77.2% in NPDS (P>0.05). Most of them were minor and transient in both surgeries. Postop early anterior chamber inflammation was mild to moderate in all cases. The incidence of wound leaks (21% in the mTRAB group and 18% in the NPDS group) and hyperfiltration related complications (14% and 13.6% respectively in the mTRAB and NPDS group) were comparable between the two procedures (p > 0.05). Intraoperative antimetabolite application was not associated with an increased rate of postoperative hyperfiltration related complications. Scarring of filtration blebs had concerned a lower percentage of mTRAB eyes (19%) than the NPDS (36%). The number for 5-FU injections was less - although not significantly - in the mTRAB than in the other group (18.6% in mTRAB versus 41% in NPDS (p=0.05). Late complications were not observed in the mTRAB group. Iris prolapse associated with increased IOP occurred in 3 of the 22 NPDS procedures (13.6%). Final mean visual acuity was unchanged compared with preop value and was similar between the 2 groups (p>0.05). Diffuse, mildly vascularized filtration blebs were observed in 84% in mTRAB and 64% in DS (p>0.05). Mean IOP significantly decreased from 24.8+/-8.3 mm Hg to 13.4+/-4,3 mm Hg in mTRAB and from 25.1+/-6.5 mm Hg to 14.7+/-4.6 mm Hg in DS (p> 0.05). It was not different between the 2 groups with and without AMETAB augmentation. 70% of the mTRAB achieved a final IOP < or = 15 mmHg vs 41% in NPDS (p<0.05). The mean number of postop medications was 0.49 in mTRAB and 0.96 in NPDS (p<0.05). Complete (target IOP reached without meds) and qualified (target IOP reached with and without meds) final success rates were 60% and 88% in mTRAB and 36.4% and 68.2% in NPDS (p>0.05).

Whether surgery was augmented with intraoperative antimetabolite or not, mTRAB revealed as a priority to be associated with comparable and even less complications than deep sclerectomy. Owing to the limitations of our study and until further confirmation, our results have suggested that mTRAB was associated with a slightly more important IOP reduction as well as higher success rates than NPDS.