PMC4899639_01
Perioperative findings. Preoperatively, a shallow anterior chamber is observed at the center (a) and periphery (b); UBM shows functional angle closure (c). Intraoperatively, difficulty with anterior chamber formation due to forward bulging of the posterior lens capsule (arrow) is encountered (d); acute uveal effusion is observed during vitrectomy (e, arrow). Postoperatively, the anterior chamber is shallow even after the uveal effusion resolved (f, postoperative day 6); UBM shows forward displacement of the iris plane and IOL due to expansion of the capsular bag (g, the arrowheads indicate the expanded posterior capsule). After the capsulotomy, the anterior chamber deepened (h) and anterior displacement of the iris plane and IOL resolved (i).
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F1
Slit-lamp examination showed a shallow anterior chamber with a van Herick grade I narrow angle (fig. 1a, b); gonioscopy revealed the presence of peripheral anterior synechia at a temporal anterior chamber angle (<0.5 clock hour). Ultrasound biomicroscopy (UBM) under mydriasis revealed functional angle closure, while neither uveal effusion nor ciliary detachment was observed in any quadrants preoperatively (fig. 1c), with an UBM-measured horizontal corneal diameter of 11.0 mm and an A-mode-measured axial length of 21.96 mm OS. During the cataract surgery, immediately after the ultrasonic tip had been removed from the anterior chamber, anterior chamber flattening occurred; the anterior chamber formation was poor during aspiration of the residual cortex due to anterior bulging of the posterior lens capsule (fig. 1d, arrow). Fundus examination during the vitrectomy showed the development of uveal effusion (fig. 1e, arrow), suggesting that acute intraoperative choroidal effusion (AICE) was the mechanism of the intraoperative anterior chamber flattening. Postoperatively, the anterior chamber remained shallow even after the choroidal detachment had subsided (fig. 1f); the IOP was 34 mm Hg with 4 ocular hypotensive medications OS on postoperative day 6. UBM showed marked distension of the capsular bag and anterior displacement of the IOL and iris plane (fig. 1g, the arrowheads indicate the expanded posterior capsule), suggesting that early postoperative capsular block syndrome (CBS) was the mechanism of the shallowing of the anterior chamber. As a result of neodymium:yttrium-aluminium-garnet laser capsulotomy, the anterior chamber deepened immediately (fig. 1h), and the iris plane and IOL moved posteriorly (fig. 1i).