Trabeculectomy Versus Nonpenetrating Surgeries
Systematic review 1
The systematic review included RCT trials and comparative observational studies with design and patient selection comparable to that of RCTs. The minimum follow-up of 6 month was requires un the srudies comoaring trabeculectomy to deep sclerectomy, viscocanalostomy, or canaloplasty. After removal of duplicates, of the 733 studies 21 were included in the meta-analysis. Studies included patients with primary open-angle glaucoma, pigmentary glaucoma, exfoliation glaucoma, and normal-tension glaucoma with no restriction to age, race, gender.
The IOP reduction after 6 months, 1 year and 2 years after surgery were compared between groups. Trabeculectomy was more effective than non-penetrating surgery (deep sclerectomy, viscocanalostomy, canaloplasty combined) in loweringg IOP at all time points (WMD at 6 months 2.12 mm Hg, 95% CI 1.62 - 2.63; WMD at 1 year 2.53 mm Hg, 95% CI 1,72 – 3,34; WMD at 2 years 2.13 mm Hg, 95% CI 0.89 - 3.36).
In subgroup analysis, there were no difference in IOP-lowering effect between trabeculectomy and deep sclerectomy if mitomycin C was used in both groups.
There were more complications (hypotony, shallow anterior chamber, hyphema, choroidal effusion, cataract formation) after trabeculectomy than in non-penetrating surgery. The only exception was hyphema, which was more common after viscocanalostomy than after trabeculectomy «Gabai A, Cimarosti R, Battistella C ym. Efficacy a...»1.
Systematic review 2
The Objectives was to compare the effectiveness of non-penetrating trabecular surgery compared with conventional trabeculectomy in people with glaucoma. Search methods, extended tp September 2013, included CENTRAL, Ovid MEDLINE, Ovid OLDMEDLINE (January 1946 to September 2013), EMBASE, LILACS,mRCT, ClinicalTrials.gov and ICTRP. Selection criteria: RCTs and quasi-RCTs on participants undergoing standard trabeculectomy for open-angle glaucoma compared to non-penetrating surgery, specifically viscocanalostomy or deep sclerectomy, with or without adjunctive measures. Standard methodological procedures expected by The Cochrane Collaboration were used.
Five studies with a total of 311 eyes (247 participants) of which 133 eyes (participants) were quasi-randomised. One hundred and sixty eyes which had trabeculectomy were compared to 151 eyes that had non-penetrating glaucoma surgery (of which 101 eyes had deep sclerectomy and 50 eyes had viscocanalostomy). The confidence interval (CI) for the odds ratio (OR) of success (defined as achieving target eye pressure without eye drops) does not exclude a beneficial effect of either deep sclerectomy or trabeculectomy (OR 0.98, 95% CI 0.51 to 1.88). The odds of success in viscocanalostomy participants was lower than in trabeculectomy participants (OR 0.33, 95% CI 0.13 to 0.81). The odds ratio for achieving target eye pressure with or without eye drops was imprecise and was compatible with a beneficial effect of either trabeculectomy or non-penetrating filtration surgery (NPFS) (OR 0.79, 95% CI 0.35 to 1.79).
Operative adjuvants were used in both treatment groups; more commonly in the NPFS group compared to the trabeculectomy group but no clear effect of their use could be determined.
Although the studies were too small to provide definitive evidence regarding the relative safety of the surgical procedures we noted that there were relatively fewer complications with non-filtering surgery compared to trabeculectomy (17% and 65% respectively). Cataract was more commonly reported in the trabeculectomy studies.
None of the five trials used quality of life measure questionnaires. The methodological quality of the studies was not good. Most studies were at high risk of bias in at least one domain and for many, there was lack of certainty due to incomplete reporting.
Authors' conclusions: This review provides some limited evidence that control of IOP is better with trabeculectomy than viscocanalostomy. For deep sclerectomy, we cannot draw any useful conclusions. This may reflect surgical difficulties in performing non-penetrating procedures and the need for surgical experience «Eldaly MA, Bunce C, Elsheikha OZ ym. Non-penetrati...»2.
Systematic review 3
The objective was to compare the hypotensive effect and safety of nonpenetrating surgery (NPS) and trabeculectomy (TE) in terms of intraocular pressure (IOP) reduction and incidence of complications. The search by March 2013 included MEDLINE and EMBASE databases. The considered interventions were TE, deep sclerectomy (DS), viscocanalostomy, and canaloplasty. The primary outcome was the mean between-group difference in the reduction in diurnal IOP from baseline to the 6- or 12-month follow-up evaluation.
Eighteen articles, accounting for 20 comparisons, were selected for data extraction and analysis. Analysis of the 6-month follow-up data showed that the pooled estimate of the mean between-group difference was -2.15 mm Hg (95% CI, -2.85 to -1.44) in favor of TE. There was no difference between the NPS subgroups. In the subgroup antimetabolite analysis, the addition of mitomycin C to TE and DS decreased the difference in the reduction in IOP (TE and DS without mitomycin C: -2.65 mm Hg [95% CI, -3.90 to -1.39]; TE and DS with mitomycin C: -0.83 mm Hg [95% CI, -2.40 to 0.74]).
In the subgroup analysis by implant addition, no significant difference induced by DS with or without drainage devices was detected (test for subgroup differences: chi(2)(1) = 0.24; P = .62).
The absolute risk of hypotony, choroidal effusion, cataract, and flat or shallow anterior chamber was higher in the TE group than in the NPS group.
Authors' conclusion: Trabeculectomy seems to be the most effective surgical procedure for reducing IOP in patients with open-angle glaucoma. However, it was associated with a higher incidence of complications when compared with NPS «Rulli E, Biagioli E, Riva I ym. Efficacy and safet...»3.