Non-penetrating deep sclerectomy with the sub flap (Ahmed’s) suture: a 12-month comparative study

Abstract

Purpose To assess the IOP-lowering effect of adding a mattress suture (Ahmed’s suture) to non-penetrating deep sclerectomy (NPDS), in patients with open angle glaucoma over a 12-month follow-up period. Methods This is a randomized controlled study comparing 52 eyes with a sub-flap Ahmed’s suture modified NPDS (group A) and 51 with a conventional NPDS (group B). Success of surgery was categorized as complete success if the IOP remained between 6 and 18 mmHg without medications and as qualified if topical medications were required. Results The post-operative IOP at the 1st week, 3rd, 6th, 9th & 12th months follow ups in group A were significantly lower (7.3 ± 2.1, 12.0 ± 2.3, 12.6 ± 2.7, 13.6 ± 3.4 & 13.8 ± 3.8 mmHg) than in B (9.2 ± 1.9, 14.0 ± 3.1, 14.8 ± 2.9, 15.4 ± 2.6 & 15.7 ± 2.7 mmHg) (p = 0.001, p = 0.001, p = 0.002, p = 0.027 & p = 0.029 respectively). The percentage of IOP reduction after 1 year was significantly higher in group A than in group B (49% vs. 36.5%). At the end of the 12-month follow-up, 81% of group A and 69% of group B were considered as complete success. Multivariate regression analysis showed lower 1st week post-operative IOP was associated with better outcome. Conclusion In conclusion, the Ahmed’s suture, a simple, novel and economic modification, maintains lower IOP levels and has a higher success rate over conventional DS, as it is 30% more effective in reducing the IOP.

Uncommon Complication Post-deep Sclerectomy: Giant Retinal Tear

“…NPDS was initially introduced in 1990, the purpose of this technique was to prevent the serious potential complications associated with penetrating surgeries, such as low eye pressure, bleeding within the eye, a flattened anterior chamber, detachment of the choroid, fluid buildup or bleeding, and inflammation within the eye [12]. They described the surgical procedure that involved removing a piece of the innermost layer of the eyeball, exposing Schlemm's canal, and removing a layer of tissue beneath it.…”

“…For example, hypotony is one of the most common and early complications after NPDS. Other complications associated with hypotony are choroidal detachment, retinal detachment, shallow AC, and hypotonous maculopathy, but these complications are rare [12].…”