New comparative ultrasound biomicroscopic findings between fellow eyes of acute angle closure and glaucomatous eyes with narrow angle

New considerations on pupillary block mechanim

“…Some papers reported that the ILCD was lower in patients with angle-closure and relative pupillary block than in normal patients (21) . Another paper showed that the ILCD of fellow eyes of APAC decreased when the illumination changed from light to dark (9) . This paper demonstrated an ILCD increase after LPI in APAC and IPAC eyes.…”

“…APAC or IPAC cases were defined by the presence of at least two symptoms: ocular or periocular pain, nausea and/or vomiting, previous history of intermittent blurring of vision with haloes; and an intraocular pressure (IOP) higher than 28 mmHg (Goldmann tonometry); the presence of three of the following signs: conjunctival injection, corneal epithelial edema, slowly reactive mid-dilated pupil, and a shallow anterior chamber; and presence of an appositional closed angle eye, verified by gonioscopy or UBM in darkness. Exclusion criteria were: posterior synechia; goniosynechia; impossibility to perform LPI due to corneal edema or corneal opacity; moderate or intense nuclear sclerosis defined as Lens Opacities Classification System (LOCS) II higher than grade 2 (NC2, NO2) (10) ; secondary glaucoma; plateau iris configuration (PIC) diagnosed by UBM exam described in a previous paper (9) to confirm the diagnosis of PIC, (this exam revels anteriorly located ciliary processes which close the ciliary sulcus and provide structural support behind the peripheral iris); unresolved APAC crisis due to unresponsiveness to medical treatment and requiring surgical management (such as LPI or trabeculectomy); history of previous trauma, or surgical procedure (laser therapy or trabeculectomy) in one or both eyes; causes of angle-closure other than relative pupillary block.…”

“…Both conditions were previously measured with an illuminance meter [Minolta T10 Illuminance Meter, Konica Minolta Sensing Inc., Osaka, Japan]). The gonioscopic classification of the Glaucoma Service described in our previous paper was used (9) . UBM exam was performed according to the technique described in a previous paper (9) .…”

“…The gonioscopic classification of the Glaucoma Service described in our previous paper was used (9) . UBM exam was performed according to the technique described in a previous paper (9) . Three clear and representative images from the temporal quadrant were selected for further analysis.…”

“…Its efficacy has been demonstrated in relation to the mechanism of angle-closure in eyes with primary angle-closure glaucoma (PACG) (8) , and the morphologic changes after LPI (6) . Other peculiarities, such as a more crowded anterior segment of the fellow APAC eyes in comparison to other narrow angle eyes have also benefited (9) . However, our knowledge about the pathophysiology of angle-closure is incomplete.…”