ABSTRACT
BACKGROUND: Disclosing the mechanism of primary angle closure glaucoma with pupillary block is important to the diagnosis as well as treatments, such as the laser peripheral iridotomy. Comparing with abundant clinical researches, there have been fewer quantitative studies of the aqueous humor flows with synechia iris configurations, and the efficacy of laser peripheral iridotomy in treating glaucoma. METHODS: Based on the mathematical models of aqueous humor flow and iris deformation, the flow fields were simulated by computational fluid dynamics with normal and synechia iris configurations (iris-lens gap of 30, 5 and 2 µm, respectively), and through one-way fluid-structure coupling technique the deformations of the iris under the flow field pressure were calculated by finite element analysis. The efficacy of glaucoma treatment with different orifice sizes was also investigated. FINDINGS: Results show that the pressure difference between anterior and posterior chambers and iris deformation increase dramatically with the iris-lens gap distance less than 5 µm, and when further decreasing this gap may lead the iris touch the cornea causing angle closure glaucoma with noticeable iris bombé. Laser peripheral iridotomy simulation results show that iridotomy size of 0.2 mm can effectively decrease the pressure difference across the iris and relieve iris bombé. INTERPRETATION: This is a biomechanical numerical study, and the results are reasonable compare to those of published works. It may shed additional light on the diagnosis and treatment of angle closure glaucoma with pupillary block.
Subject(s)
Aqueous Humor , Laser Therapy , Humans , Intraocular Pressure , Iris/surgery , Laser Therapy/methods , LasersABSTRACT
A series of Al-doped BiVO4 composites have been synthesized via the hydrothermal method for methylene blue (MB) degradation application. The reasons for the improvement of photocatalytic performance was explained from the perspective of optics. Transient photovoltage (TPV) measurements suggested that the surface states have the priority to capture photogenerated carriers, and the Al2O3 surface passivation layer can prolong the lifetime of charge carrier. The results of surface photovoltage (SPV), transient photovoltage (TPV), and surface photocurrent (SPC) measurements suggested that the coexistence of Al3+ and Al2O3 caused by the appropriate doping would improve the transfer property and prolong the lifetime of photogenerated carriers. Finally, the possible photocatalytic mechanism is expounded to illustrate the photogenerated charge behavior under visible light irradiation. This work provides a better understanding of the synergistic effect of Al-doping and Al2O3 passivation layer on enhancing the photocatalytic performance.
ABSTRACT
To newly describe the clinical and histopathological characteristics of epibulbar complex cartilaginous choristoma incidentally observed in a series of pterygium excision patients.Noncomparative case series with chart review of 8 patients.During a 4-year period, we identified 8 cases of conventional unilateral nasal subpterygial cartilaginous choristoma in 1799 pterygium patients and analyzed their clinicopathological features. The incidence rate of this entity is 0.44% in pterygium patients. All of the cartilaginous choristomas were buried deep in the caruncle, covered by the pterygium, and embedded in tenon facia tissue. Its clinicopathological characteristics include hyaline cartilaginous tissue that is surrounded by fibrous connective tissue and smooth muscle bundles. S-100 protein-staining specifically revealed chondrocytes embedded within chondroid matrix.Epibulbar complex cartilaginous choristoma covered by pterygia and predominantly observed in the older population is rare. The lesions were buried deep in the caruncle, covered by the pterygium and embedded in tenon fascia tissue. These findings are inconsistent with those in previous reports.
