Nonpenetrating deep sclerectomy does not increase risk of sudden visual loss
Nonpenetrating deep sclerectomy (NPDS) effectively reduces intraocular pressure (IOP) without subsequently increasing the risk of sudden visual loss, a recent study has shown.
Seventy-three eyes (mean age, 60±13 years; 65 percent male) with severe or end-stage glaucoma were included in the monocentre database study. All eyes underwent NPDS. Sudden visual loss, or the “wipe-out” phenomenon, was defined as the permanent drop in visual acuity to <20/200 after the procedure.
The mean IOP under maximal medical therapy and before the procedure was 22±9 mm Hg. Preoperative visual acuity had a mean value of 0.34±0.50 logMAR; six eyes had visual acuity of 20/400 or worse.
In most of the eyes (75 percent; n=55), NPDS was the sole procedure performed; the remaining 25 percent (n=18) received additional phacoemulsification and intraocular lens implantation. Within the first 6 months after surgery, there were no reported cases of the “wipe-out” phenomenon.
Moreover, there was no significant change in mean visual acuity in the same time frame (0.34±0.5 to 0.31±0.49 logMAR; p=0.6).
On the other hand, there was a significant drop in mean IOP at 6-month follow-up (22.0±8.8 to 13.5±4.5 mm Hg; p<0.001). Most (77 percent; n=56) of the eyes had IOP <16 mm Hg while an even greater percentage (95 percent; n=69) had IOP <21 mm Hg. More than half (64 percent; n=47) saw an IOP decrease of >20 percent.
“Consideration of NPDS in end-stage and severe glaucoma is advisable given its low risk of intraoperative and postoperative complications and the low risk of wipe out. This surgery should probably be offered with less apprehension about the risk of ‘wipe-out’ in end-stage glaucoma,” said researchers.