3T Ophthalmics (United States)

Positron Emission Tomography/Computed Tomography (PET/CT) combines metabolic and anatomical information improving the precision and accuracy of oncological diagnostics. The standardized uptake value (SUV) measures tumor metabolism, yet its accuracy is influenced by the partial volume effect (PVE), impacting small lesion detection. This study aims to refine PVE corrections for small lesions using an in-house customized, special anthropomorphic phantom. Scans of this phantom which contained spheres of different sizes were performed across four hospitals at different PET/CT systems from various manufacturers (Siemens and Philips analog PET/CT systems, GE analog and digital PET/CT systems). The phantom contained six custom-designed cylinders with embedded spheres simulating sub-centimeter (0.3, 0.5, 0.9) and centimeter (1.3, 1.9, 2.8) lesions. Scans were performed separately for each sphere in the thorax, abdomen, and pelvis regions at all sites. Recovery Coefficients (RCs) were calculated to correct SUV values, demonstrating that RCs vary by sphere size and anatomical region but not change significantly among scanners. RCs are approaching unity for larger spheres, ensuring accurate SUV measurements. However, small spheres (< 0.5 cm) exhibited significant measurement challenges due to PVE. The anthropomorphic phantom proved effective in obtaining realistic SUV-corrected values, offering a promising tool for enhancing the accuracy and standardization of PET imaging in oncology. This study underscores the necessity for advanced imaging technologies and standardized RC application in clinical settings to improve the quantification of PET imaging, particularly in small lesion detection.

A modular approach to install functional chain-end groups through a redox-responsive disulfide linkage is utilized to fabricate a targeted delivery system using self-assembly.

In patients with ocular hypertension or glaucoma, all treatments aim to lower intraocular pressure (IOP) by modulating aqueous humour (AH) production and/or uveoscleral and trabecular meshwork/Schlemm's canal AH drainage. PG analogues are considered to be the 'gold standard' treatment and are the most frequently used IOP-lowering agents. Recent data support an important role for NO in regulating IOP. Thus, novel PG analogues carrying a NO-donating moiety were recently advanced. Latanoprostene bunod (LBN) and NCX 470, NO-donating derivatives of latanoprost and bimatoprost, respectively, are examples of such compounds. LBN ophthalmic solution, 0.024% (Vyzulta™), showed greater IOP-lowering efficacy compared with that of Xalatan® (latanoprost ophthalmic solution, 0.005%) or 0.5% timolol maleate in clinical settings. NCX 470 was found to be more effective than bimatoprost in animal models of ocular hypertension and glaucoma. Selective EP2 receptor agonists (i.e. taprenepag isopropyl, omidenepag isopropyl and aganepag isopropyl) and non-selective prostanoid receptor agonists (i.e. ONO-9054, sepetaprost isopropyl) that concomitantly stimulate FP and EP3 receptors have also been shown to hold promise as effective IOP-lowering agents. LINKED ARTICLES: This article is part of a themed section on Eicosanoids 35 years from the 1982 Nobel: where are we now? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.8/issuetoc.

Intrastromal corneal crystals developed in 11 of 49 monkey eyes with hydrogel intracorneal lenticules followed over a 4 year period. All of the eyes, except one, underwent synthetic keratophakia via a microkeratome incision. The diagnosis of crystal formation was initially made by slit-lamp examination and confirmed with specular microscopy (from 21 to 150 days post-hydrogel keratophakia). The crystals were noted to lie in a plane adjacent to the hydrogel lenticule and specular microscopy revealed polychromatic, hyperrefringent crystals with either a rectangular or linear morphology. Prior to intrastromal crystal formation, these corneas developed early postoperative stromal edema (< 3 weeks). We hypothesize that early stromal edema in combination with the hydrogel intracorneal lenticule induced the production of lipid crystals by stromal keratocytes.