Yalvac 2004.
| Methods |
Unit of analysis: 1 eye per participant Methods of allocation: not stated Masking (outcome assessment): not stated Exclusions after randomisation: 1 participant from the viscocanalostomy group was excluded and was replaced by another Losses to follow‐up: none stated Compliance: not stated Study design (intention‐to‐treat or available case analysis): 50 eyes of 50 participants were divided into 2 groups (25 eyes per group). One group underwent trabeculectomy and the other viscocanalostomy. The 2 groups were followed up to 3 years. |
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| Participants |
Country of enrolment: Turkey Number randomised: 50 eyes of 50 participants Age: Trabeculectomy group: 66.8 ± 10.2 (range 44 to 70) Viscocanalostomy group: 53.6 ± 12.6 (range 42 to 72) Sex: Trabeculectomy group: 6 females, 19 males Viscocanalostomy group: 8 females, 17 males Ethnicity: not stated Main inclusion criteria: patients with uncontrolled POAG despite maximally tolerated medical therapy Main exclusion criteria: primary angle‐closure, neovascular, congenital, traumatic and uveitic glaucoma and previous ocular surgery |
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| Interventions |
Type of surgical method: viscocanalostomy versus trabeculectomy Use of adjuvants: No adjunctive antimetabolite injections were given and no neodymium:YAG laser goniopunctures were performed in any participant postoperatively Any immediate (within 2 weeks) postoperative interventions: none stated |
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| Outcomes |
IOP total success (IOP 6 to 21 mmHg without medication): Figures estimated from Kaplan Meier plots Trabeculectomy group: complete success at 1 year was 55.1% Viscocanalostomy group: complete success at 1 year was 35.3% IOP qualified success (6 to 21 mmHg with medication): Trabeculectomy group: qualified success at 1 year was 90.5% Viscocanalostomy group: qualified success at 1 year was 83.1% IOP failure: Trabeculectomy group: failure at 1 year was 9.5% Viscocanalostomy group: failure at 1 year was 16.9% Field of vision: not stated Optic disc: not stated Drop in visual acuity 2 lines or more: Trabeculectomy group: 8 participants (32%) (progressive cataract formation in 7 eyes and AMD in 1 eye) Viscocanalostomy group: 4 participants (16%) (haemorrhagic Descemet’s membrane detachment in 1 eye, cataract formation in 2 eyes and AMD in 1 eye) Drop in postoperative medication score: No clear data are available at 1 year on the drop in anti‐glaucoma medication Adverse effects: Trabeculectomy group: 7 participants (28%) had hypotony, 2 participants (8%) had hyphaema, 1 participant (4%) had pupillary block, 3 participants (12%) had bleb encapsulation and 7 participants (28%) had progressive cataract Viscocanalostomy group: 1 participant (4%) had hypotony, 1 participant (4%) had hyphaema, 1 participant (4%) had bleb encapsulation, 1 participant (4%) had haemorrhagic Descemet’s membrane detachment and 2 participants (8%) had progressive cataract Length of follow‐up: 3 years Exclusions and drop outs: 1 participant in the viscocanalostomy group was excluded and replaced. No drop outs were reported. |
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| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | The authors state that participants were assigned randomly but no definite method of randomisation was described in the study |
| Allocation concealment (selection bias) | Unclear risk | No information about allocation concealment was given in the study |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | It is unclear whether the persons assessing outcome were unaware of the nature of the procedure in each eye of the participant |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Rates of follow‐up were similar in both groups ‐ however, 1 patient was excluded and replaced by another participant because of inadvertent trabeculo‐Descemet's membrane perforation |
| Selective reporting (reporting bias) | Unclear risk | Insufficient evidence to judge as high or low risk |
AC: anterior chamber AMD: age‐related macular degeneration DS: deep sclerectomy IOP: intraocular pressure mg: milligram ml: millilitre mmHg: millimetres of mercury MMC: Mitomycin C Nd:YAG: neodymium: yttrium–aluminium‐garnet PEXG: pseudoexfoliative glaucoma POAG: primary open‐angle glaucoma TP: trabeculectomy with the Crozafon‐De Laage Punch 5‐FU: 5‐Fluorouracil