pigment dispersion
Recently Published Documents


TOTAL DOCUMENTS

470
(FIVE YEARS 69)

H-INDEX

28
(FIVE YEARS 2)

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 494
Author(s):  
Dariusz Brząkalski ◽  
Robert E. Przekop ◽  
Miłosz Frydrych ◽  
Daria Pakuła ◽  
Marta Dobrosielska ◽  
...  

In this work, silsesquioxane and spherosilicate compounds were assessed as novel organosilicon coupling agents for surface modification of TiO2 in a green process, and compared with their conventional silane counterparts. The surface-treated TiO2 particles were then applied in preparation of epoxy (EP) composites and the aspects of pigment dispersion, suspension stability, hiding power, as well as the composite mechanical and thermal properties were discussed. The studied compounds loading was between 0.005–0.015% (50–150 ppm) in respect to the bulk composite mass and resulted in increase of suspension stability and hiding power by over an order of magnitude. It was found that these compounds may be an effective alternative for silane coupling agents, yet due to their low cost and simplicity of production and manipulation, silanes and siloxanes are still the most straight-forward options available. Nonetheless, the obtained findings might encourage tuning of silsesquioxane compounds structure and probably process itself if implementation of these novel organosilicon compounds as surface treatment agents is sought for special applications, e.g., high performance coating systems.


2021 ◽  
Vol 4 (6) ◽  
pp. 596
Author(s):  
Troy Teeples ◽  
Pamela Rowlett ◽  
Cara Capitena Young
Keyword(s):  

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Nicolás Rivera-Valdivia ◽  
Karla Arteaga-Rivera ◽  
Juliana Reyes-Guanes ◽  
Natalia Neira-Segura ◽  
Alejandra de-la-Torre

Abstract Background Moxifloxacin is a fourth-generation fluoroquinolone used as a second-line treatment for multiple bacterial infections. Uveitis has been described as an adverse effect related to this medication. Although several case reports have been published describing uveitis and bilateral acute iris transillumination syndrome related to moxifloxacin, we present a unique case of a patient with severe sequelae associated with bilateral acute iris transillumination syndrome secondary to the use of oral moxifloxacin. Case presentation A 45-year-old Colombian hispanic female presented bilateral conjunctival hyperemia, decreased visual acuity, blurred vision, photophobia, and ocular pain after 15 days of treatment with systemic moxifloxacin for an upper tract respiratory infection. The patient presented unilateral anterior chamber pigment dispersion, mydriatic and nonreactive pupils, extensive iris transillumination defects, and secondary glaucoma. Blood and aqueous humor tests were negative for infectious and autoimmune diseases. Moxifloxacin-induced bilateral acute iris transillumination syndrome was diagnosed. Permanent sequelae such as ocular pain, photophobia, and focus difficulty secondary to severe bilateral iridian atrophy and inability of synkinetic reflex were left. Additionally, glaucoma was diagnosed, and Ahmed valve implantation was required. Conclusions We should be aware of the possible association between moxifloxacin and bilateral acute iris transillumination syndrome. A detailed anamnesis, adequate examination, and laboratory tests are necessary to reach an early diagnosis and treatment to avoid unnecessary therapies. Larger studies should be carried out to understand the pathophysiology, diagnosis, management, and sequelae of the disease.


Medicine ◽  
2021 ◽  
Vol 100 (31) ◽  
pp. e26567
Author(s):  
Rongyao Zhou ◽  
Qi Tang ◽  
Liping Pu ◽  
Guoping Qing

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Wei ◽  
Xueqing Yu ◽  
Lu Yang ◽  
Chan Xiong ◽  
Xu Zhang

Abstract Background With the rapid development of intraocular collamer lens (ICL) operation, it is foreseeable that we will encounter a large number of glaucoma patients with ICL implantation history. However, our current understanding of the treatment of glaucoma patients with ICL is limited. Hence we report a rare case of refractory glaucoma after intraocular collamer lens and intraocular lens implantation in a patient who underwent unsuccessful transscleral cyclophotocoagulation, which led to intraocular collamer lens displacement, angle closure and uncontrolled intraocular pressure. Case presentation A 39-year-old woman presented with intractably elevated intraocular pressure in the right eye. Since her intraocular collamer lens implantation surgery in 2017, her intraocular pressure had remained over 40 mmHg while using 3 types of anti-glaucoma medications. The patient had a history of phacoemulsification and posterior chamber phakic intraocular lens implantation for complicated cataracts secondary to uveitis in 2006. On gonioscope examination, there were signs of pigment dispersion, and the anterior chamber angle was open. Ultrasound biomicroscopy examination showed contact and rubbing between the intraocular collamer lens and posterior surface of the iris. And typical advanced glaucomatous optic neuropathy and visual field defects were observed. Transscleral cyclophotocoagulation was performed to control the intraocular pressure and prevent further visual field loss. However, the intraocular collamer lens was displaced after transscleral cyclophotocoagulation, which resulted in formation of a shallow anterior chamber 1 week later, angle closure and loss of intraocular pressure control 1 month later, even though the maximum dose of anti-glaucoma medication was used. Finally, an Ahmed glaucoma valve was successfully implanted in her anterior chamber, and the glaucoma was controlled, as observed at the 10-month follow-up. Conclusions Pigment dispersion is a common phenomenon after intraocular collamer lens implantation and may accelerate the progression of glaucoma. Transscleral cyclophotocoagulation should be carefully considered in glaucoma patients with elevated intraocular pressure after intraocular collamer lens implantation, given that transscleral cyclophotocoagulation may cause intraocular collamer lens displacement.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Carly van der Heide ◽  
Wes Goar ◽  
Kacie J. Meyer ◽  
Wallace L. M. Alward ◽  
Erin A. Boese ◽  
...  

Abstract Background Glaucoma is a leading cause of visual disability and blindness. Release of iris pigment within the eye, pigment dispersion syndrome (PDS), can lead to one type of glaucoma known as pigmentary glaucoma. PDS has a genetic component, however, the genes involved with this condition are largely unknown. We sought to discover genes that cause PDS by testing cohorts of patients and controls for mutations using a tiered analysis of exome data. Results Our primary analysis evaluated melanosome-related genes that cause dispersion of iris pigment in mice (TYRP1, GPNMB, LYST, DCT, and MITF). We identified rare mutations, but they were not statistically enriched in PDS patients. Our secondary analyses examined PMEL (previously linked with PDS), MRAP, and 19 other genes. Four MRAP mutations were identified in PDS cases but not in controls (p = 0.016). Immunohistochemical analysis of human donor eyes revealed abundant MRAP protein in the iris, the source of pigment in PDS. However, analysis of MRAP in additional cohorts (415 cases and 1645 controls) did not support an association with PDS. We also did not confirm a link between PMEL and PDS in our cohorts due to lack of reported mutations and similar frequency of the variants in PDS patients as in control subjects. Conclusions We did not detect a statistical enrichment of mutations in melanosome-related genes in human PDS patients and we found conflicting data about the likely pathogenicity of MRAP mutations. PDS may have a complex genetic basis that is not easily unraveled with exome analyses.


2021 ◽  
pp. 1-8
Author(s):  
Maciej Czepita

BACKGROUND: Quantification of melanin pigment release in pigment dispersion syndrome as well as observations of melanin brightness changes can be valuable information in the management of this rare ocular disease. OBJECTIVES: Previous studies have focused on examining the iris pigment epithelium and aqueous humor. Therefore, the aim of this study was to examine the cornea. METHODS: A novel technique was developed for this purpose based on aperture photometry. Slit lamp digital video images of the cornea were recorded. A single frame from each video recording based on the quality was chosen for further processing and analysis. Aperture photometry was performed with AstroImageJ open source software. Aperture selection was performed automatically. Melanin particles displaying a signal-to-noise ratio above 20 were analyzed. RESULTS: A total of 16 melanin particles from the right eye of the patient participating in the study were detected and a further 9 melanin particles from the left eye. The examined area of the cornea measured 348 × 348 pixels in the image. Brightness differed by as much as 8.98 × among particles in the right eye and 2.03 × in the left eye. CONCLUSIONS: It seems feasible for this new method to be potentially used in the monitoring of patients with pigment dispersion syndrome and pigmentary glaucoma as well as in other ocular diseases.


Sign in / Sign up

Export Citation Format

Share Document