[Assessment of anterior segment anatomy by OCT after non penetrating deep sclerectomy]

Thanks to recent progress in imaging techniques, the anatomy of the anterior segment can be measured accurately and noninvasively. The objective of this study was to assess early postoperative changes induced by non penetrating deep sclerectomy (NPDS) on anterior chamber depth, anterior chamber angle and central corneal thickness.

Twenty eyes of 20 patients with primary open-angle glaucoma (POAG) that underwent NPDS were studied. All patients underwent ophthalmologic examination including non invasive analysis of the anterior segment architecture. Visante(®) OCT was used to determine anterior chamber depth, central corneal thickness, scleral spur angle (SSA), angle opening distance at 500μm (AOD 500), and trabecular-iris space area at 500 μm (TISA 500) in the nasal and temporal quadrants. These evaluations were performed at 1 day preop, then day 1, day 7 and day 30 after surgery.

Preoperatively, SSA, AOD 500 and TISA 500 were 37.24 ± 12.67°, 0.42 ± 0.25 mm and 0.15 ± 0.1 mm(2), respectively, in the nasal quadrant, and 39.62 ± 12.41°, 0.46 ± 0.25 mm and 0.16 ± 0.08 mm(2), respectively, in the temporal quadrant. Mean anterior chamber depth, central corneal thickness and intraocular pressure (IOP) were 3.09 ± 0.54 mm, 530 ± 34.3 μm and 20.43± 7.25 mmHg respectively. After NPDS, aside from IOP being significantly decreased on day 1 (5.57 ± 2.78 mmHg, P<0.0001), day 7 (8.2 ± 3.12 mmHg, P<0.0001) and day 30 (13.4 ± 3.47 mmHg, P=0.001), none of the other study parameters was significantly modified.

No relationship was found between IOP and anterior chamber architecture after NPDS. NPDS appears to significantly reduce IOP while maintaining the architecture of the anterior chamber, and in particular, the anterior chamber angle.