Purchase this article with an account.
William E. Sponsel, Sylvia L. Groth; Visual Field, IOP, and Medication Changes with MMC-augmented Nonpenetrating Deep Sclerectomy (NPDS). Invest. Ophthalmol. Vis. Sci. 2012;53(14):5041.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Trabeculectomy is currently the mainstay in medically refractory glaucoma treatment. Nonpenetrating deep sclerectomy (NPDS) is a related glaucoma filtering procedure that aims to control IOP by enhancing drainage of aqueous humor without disrupting the trabecular endothelial layer. Because this may reduce the risk of early post-op hypotony and hyphema, certain higher-risk patients might be considered for NPDS to minimize post-surgical complications.
A quality assurance analysis was performed of 87 consecutive eyes that underwent Mermoud-style ruby-knife/diamond blade NPDS procedures with confirmation of an intact internal trabeculum prior to three 1-min Weck-cel applications of 0.4 mg/ml Mitomycin-C, one to the scleral lake and two between the external scleral flap and tenons capsule. Perisulcal limbus-based conjunctival incisions were used, closed in two-layers with 8-0 polyglycan suture on a tapered BV needle. The 5x6 mm rectangular scleral flaps beneath were closed with 3 interrupted 10-0 nylon sutures posteriorly. No collagen or other implants were placed. Paired t-test assessments of pre-op SITA full-threshold 30-2 Humphrey Mean Deviation (MD) versus 1-yr post-op MD, and of pre-op IOP, total glaucoma medications (topical and oral), and acuity versus corresponding 3-,6-,9-,12-, & 18-mo post-op values were performed. Linear regression change analysis to assess association between variables was also performed.
Mean Humphrey visual field MD improved from -12.20 ± (sem)0.95 dB pre-op to -10.85 ±0.95 at one year (p= 0.002). Over 90% of participants had undergone perimetric testing multiple times prior to their surgery, and exclusion of subjects without prior perimetric experience did not significantly alter these values. Sustained therapeutic-level IOP reduction was seen at all 5 post-op intervals, with no tachyphylactic regression (from pre-op 22.2 ±0.9 mmHg to 12.4 ±0.4 at 1 yr, and 11.7 ±0.5 at 18-mo (p<0.0001). Mean visual acuity remained stable throughout the study period. Incidence of hypotony (IOP<4 mmHg) was low (6/410; 1.5%), and there were no hyphemata observed. Mean glaucoma medications dropped from 3.0 ±0.12 to 0.3 ±0.07 at 18 months (P<0.0001). While most eyes demonstrated visual field improvement and IOP reduction, no correlation was found between the extent of these changes.
NPDS is an underutilized and potentially valuable glaucoma surgical option, with these data showing substantial (>40%) sustained IOP reduction to safe therapeutic levels through 18 months, with significant improvement in visual field performance not attributable to learning effect, minimal postoperative morbidity, and a 90% reduction in reliance on medical therapy.
This PDF is available to Subscribers Only