The efficacy and safety of reducing intraocular pressure to single-digit levels in Normal-tension glaucoma: A systematic review and meta-analysis.
Beatriz Araújo-Azevedo, Renato Ferreira-da-Silva, João Barbosa-Breda
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In 30 seconds
This systematic review and meta-analysis assessed whether lowering intraocular pressure (IOP) to single-digit levels benefits treated patients with progressive normal-tension glaucoma. Nine observational studies comprising 270 eyes were included; all evaluated trabeculectomy. Mean visual-field mean deviation (MD) slope improved from -0.91 ± 0.27 dB/year before surgery to -0.25 ± 0.16 dB/year afterward. The pooled mean difference was 0.59 dB/year (95% CI: 0.38 to 0.80; p < 0.0001). Single-digit IOP was achievable and sustainable, but hypotony-related complications and hyphema were reported.
Key findings
- Mean IOP fell from 14.77 ± 0.95 mmHg preoperatively to 9.82 ± 1.55 mmHg postoperatively, a mean reduction of 33.65 ± 10.37%.
- Mean visual-field MD slope changed from -0.91 ± 0.27 dB/year before trabeculectomy to -0.25 ± 0.16 dB/year afterward.
- Meta-analysis found a pooled MD-slope mean difference of 0.59 dB/year (95% CI: 0.38 to 0.80; p < 0.0001).
- Hypotony-related complications and hyphema were among the most common postoperative complications; hypotony was generally transient.
Why it matters
Progressive normal-tension glaucoma may continue despite treatment, and these findings suggest that further IOP reduction can be associated with slower visual-field progression. The results also highlight a clinically important trade-off: reaching single-digit pressures through trabeculectomy may carry hypotony-related risks, so potential benefit and safety need to be considered together.
What to keep in mind
The evidence came from nine observational studies involving 270 eyes, and all studies included trabeculectomy; the findings therefore do not establish a causal effect or compare a broad range of interventions.