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Efficacy of Intraoperative 9-0 Nylon Thread Insertion for Preventing Hypotony-Related Complications Following
Takahiro Matsuoka1,2, Takahiro Usami1, Hiroki Kaneko1
1Department of Ophthalmology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Background:
Early postoperative hypotony remains a significant complication following PreserFlo MicroShunt (PMS) implantation, potentially leading to serious sequelae including choroidal detachment and hypotensive maculopathy. This study evaluated the effectiveness of intraoperative 9-0 nylon thread insertion (NTI) technique in preventing hypotony-related complications.
Methods:
This retrospective comparative study included 81 eyes of 63 patients who underwent PMS implantation with mitomycin C between September 2023 and June 2025. Eyes were divided into NTI group (59 eyes, 42 patients) and Non-NTI group (22 eyes, 21 patients). The primary outcome was the incidence of composite hypotony-related complications (choroidal detachment and/or hypotensive maculopathy) during 6-month follow-up. Secondary outcomes included intraocular pressure (IOP) changes, medication score reduction, and timing of suture removal. Statistical analyses incorporated cluster correction for bilateral cases.
Results:
Baseline characteristics, including glaucoma subtype distribution, were comparable between groups. The composite hypotony-related complication rate was significantly lower in the NTI group (11.9% vs 54.5%, p<0.001; odds ratio 0.112, 95% CI 0.039-0.321). Kaplan-Meier analysis demonstrated superior complication-free survival in the NTI group (log-rank p<0.001, hazard ratio 0.094, 95% CI 0.035-0.252). The median IOP at postoperative day 1 was significantly higher in the NTI group (10.0 [8.0-14.0] vs 5.8 [5.0-8.5] mmHg, p<0.001), indicating effective early hypotony prevention. At 6 months, both groups achieved comparable IOP control (13.0 [10.9-14.0] vs 13.0 [11.0-16.0] mmHg, p=0.324) with medication-free rates of 74.6% and 59.1%, respectively (p=0.190).
Conclusion:
Intraoperative 9-0 nylon thread insertion significantly reduces hypotony-related complications following PMS implantation without compromising IOP control at 6 months or medication reduction, representing a safe and effective surgical modification.
Insights
Intraoperative 9-0 nylon thread insertion (NTI) significantly reduces hypotony complications after PreserFlo MicroShunt (PMS) surgery. This technique prevents hypotony without negatively impacting long-term intraocular pressure control.
Area of Science:
- Ophthalmology
- Glaucoma Surgery
- Surgical Techniques
Background:
- Postoperative hypotony is a significant complication of PreserFlo MicroShunt (PMS) implantation.
- Hypotony can lead to serious issues like choroidal detachment and hypotensive maculopathy.
Purpose of the Study:
- To evaluate the effectiveness of intraoperative 9-0 nylon thread insertion (NTI) in preventing hypotony-related complications after PMS implantation.
Main Methods:
- Retrospective comparative study of 81 eyes undergoing PMS implantation with mitomycin C.
- Comparison between NTI group (59 eyes) and Non-NTI group (22 eyes).
- Primary outcome: incidence of composite hypotony-related complications over 6 months.
Main Results:
- NTI group showed significantly lower complication rates (11.9% vs 54.5%, p<0.001).
- Higher median intraocular pressure (IOP) on postoperative day 1 in the NTI group (10.0 vs 5.8 mmHg, p<0.001).
- Comparable IOP control and medication-free rates at 6 months between groups.
Conclusions:
- Intraoperative 9-0 nylon thread insertion is a safe and effective modification for PMS implantation.
- NTI significantly reduces hypotony-related complications.
- The technique does not compromise IOP control or medication reduction at 6 months.