No abstract

Background Glaucoma is the leading cause of blindness worldwide. Glaucoma drainage devices and minimally invasive glaucoma surgeries (MIGS) often present with tradeoffs in safety and durability of efficacy. Using a rabbit model, we examined the biocompatibility and feasibility of VisiPlate, a novel, ultrathin, tubeless subconjunctival shunt comprised of a network of microchannels. Methods Six naive female New Zealand White rabbits received implants (three only in the right eye with contralateral eye untreated and three in both eyes) composed of a 400-nm-thick aluminum oxide core coated with 2 µm of parylene-C, manufactured with microelectromechanical systems (MEMS) techniques. Tonometry, slit lamp exam, clinical exam, fluorescein patency testing, and histopathology were performed. Results VisiPlate demonstrated IOP-lowering of 20–40% compared to baseline at each time point over the course of 3 months in the nine implanted eyes. All eyes developed blebs over the implant, and fluorescein testing demonstrated fluid patency at 22 days post-implantation. Slit lamp and clinical observations showed that VisiPlate was well tolerated, with low levels of conjunctival congestion, conjunctival swelling, aqueous flare, hyphema, and iris involvement from surgery that resolved over time. At sacrifice time points of 93 days and 180 days, the only notable observations were mild levels of conjunctival congestion in implanted eyes. Histopathology showed minimal tissue response and no obvious inflammation, fibrosis, or necrosis around the implant. Conclusions The results of this in vivo study demonstrate the biocompatibility and IOP-lowering effect of a multichannel, ultrathin subconjunctival shunt in a rabbit model. The data suggest that VisiPlate may safely enhance aqueous outflow and significantly reduce intraocular pressure.

No abstract

Précis: Anterior chamber depth (ACD) change after pupillary dilation is correlated with lens vault (LV) and anterior chamber width (ACW), as observed by swept-source optical coherence tomography (SS-OCT) at both horizontal and vertical scans in patients with primary angle closure suspect and cataract. Purpose: The purpose of this study is to evaluate the association between ACD and other anterior chamber parameters after pharmacological dilation in patients with primary angle closure suspect and cataract. Patients and Methods: SS-OCT was performed for 78 patients at baseline and 1 hour after pharmacological dilation. Measurements were taken at 8 evenly spaced axes at 250, 500, and 750 μm from the scleral spur. Pearson correlation coefficient (ρ) was used to evaluate the relationship between averaged ACD change and other SS-OCT parameters. Multivariable regression analyses were performed to determine the parameters that predict ACD change. Results: Across all 14 dimension and angle parameters, 12 parameters at the 270-degree axis and 10 parameters at the 0-degree axis yielded significant correlations with ACD change (ρ=0.24–0.55, P<0.05). Angle parameters were most significantly correlated to ACD change 750 µm from the scleral spur. The prediction model for ACD change after pharmacological dilation at 0 degree included decreased LV, wider ACW, and increased trabecular iris space area (all P≤0.001). The prediction model for ACD change at 270 degrees included: decreased LV, wider ACW, larger change in anterior chamber volume, larger baseline anterior chamber volume, and smaller baseline angle opening distance (all P≤0.03). Conclusions: LV and ACW, as measured in both vertical and horizontal scans, were found to be determinants of the ACD change after pharmacological pupillary dilation. Examination of these parameters may help identify patients at higher risk of developing angle-closure disease.