A 46-year-old woman with no known past medical history presented with sudden painless visual impairment in the left eye. Ocular examination showed a swollen and hyperaemic left optic disc with a small and crowded right optic disc. Intraocular pressures were moderately elevated. Investigations for underlying ischaemic and inflammatory markers were normal. A diagnosis of left non-arteritic anterior ischaemic optic neuropathy (NAAION) was made, with associated ocular hypertension. On follow-up, NAAION resolved with anti-glaucoma medication and repeat fundus examination confirmed the presence of an underlying hypoplastic disc. The coexistence of optic disc hypoplasia and elevated intraocular pressure may further augment the risk of developing NAAION.Leber’s hereditary optic neuropathy (LHON) is a mitochondrial genetic disease that leads to acute or subacute, painless, bilateral loss of vision, caused by degeneration of retinal ganglion cells that most affects men in their second or third decade of life. We describe a woman with compressive optic neuropathy with a concurrent LHON-associated mitochondrial mutation. Temporal hemifield defect connected to central scotoma and concurrent abduction limitation are diagnostic clues in identifying chiasmal compression with craniopharyngioma. This case emphasizes an awareness of the possible coexistence of compressive and hereditary optic neuropathy.Platelet-rich plasma has become one of the most widely used facial cosmetics fillers. We evaluated four patients treated by cosmetologists with platelet-rich plasma injections who developed irreversible blindness due to iatrogenic occlusion of the ophthalmic artery; immediately after the injection in the glabellar area in three cases and in the nasolabial fold in one case. Early after the injections the fundi of all patients demonstrated central retinal artery and choroidal occlusions. Later, two patients developed retinal pigment dispersion and one of them a pigmented optic disc. The scars on the skin showed similar characteristics in all patients, which could constitute an important marker in the presumptive diagnosis of platelet-rich plasma injection associated complications.We sought to investigate the reliability of standard conventional perimetry (SCP) in neurologically impaired (NI) children using the examiner-based assessment of reliability scoring system and to determine the difference in time to diagnosis of a visual field defect between SCP and a behavioural visual field (BVF) test. Patient records of 115 NI children were retrospectively analysed. The full field peritest (FFP) had best reliability with 44% ‘good’ scores versus 22% for Goldmann perimetry (p less then .001). The mean age of NI children able to perform SCP was 8.3 years versus 4.6 years for the BVF test (p less then .001). Use of the BVF test may significantly reduce time to diagnosis.Self-assembly of amphiphilic polymers into micelles is an archetypical example of a “self-confined” system due to the formation of micellar cores with dimensions of a few nanometers. In this work, we investigate the chain packing and resulting shape of C n -PEOx micelles with semicrystalline cores using small/wide-angle X-ray scattering (SAXS/WAXS), contrast-variation small-angle neutron scattering (SANS), and nuclear magnetic resonance spectroscopy (NMR). Interestingly, the n-alkyl chains adopt a rotator-like conformation and pack into prolate ellipses (axial ratio ϵ ≈ 0.5) in the “crystalline” region and abruptly arrange into a more spheroidal shape (ϵ ≈ 0.7) above the melting point. We attribute the distorted spherical shape above the melting point to thermal fluctuations and intrinsic rigidity of the n-alkyl blocks. We also find evidence for a thin dehydrated PEO layer (≤1 nm) close to the micellar core. The results provide substantial insight into the interplay between crystallinity and molecular packing in confinement and the resulting overall micellar shape.Many biopolymer hydrogels are environmentally responsive because they are held together by physical associations that depend on pH and temperature. Here, we investigate how the pH and temperature responses of the rheology of hyaluronan hydrogels are connected to the underlying molecular interactions. Hyaluronan is an essential structural biopolymer in the human body with many applications in biomedicine. Using two-dimensional infrared spectroscopy, we show that hyaluronan chains become connected by hydrogen bonds when the pH is changed from 7.0 to 2.5 and that the bond density at pH 2.5 is independent of temperature. Temperature-dependent rheology measurements show that because of this hydrogen bonding the stress relaxation at pH 2.5 is strongly slowed down in comparison to pH 7.0, consistent with the sticky reptation model of associative polymers. From the flow activation energy, we conclude that each polymer is cross-linked by multiple (5-15) hydrogen bonds to others, causing slow macroscopic stress relaxation, despite the short time scale of breaking and reformation of each individual hydrogen bond. Our findings can aid the design of stimuli-responsive hydrogels with tailored viscoelastic properties for biomedical applications.Similar to macroscopic ropes and cables, long polymers create knots. Bemcentinib We address the fundamental question whether and under which conditions it is possible to describe these intriguing objects with crude models that capture only mesoscale polymer properties. We focus on melts of long polymers which we describe by a model typical for mesoscopic simulations. A worm-like chain model defines the polymer architecture. To describe nonbonded interactions, we deliberately choose a generic “soft” repulsive potential that leads to strongly overlapping monomers and coarse local liquid structure. The soft model is parametrized to accurately reproduce mesoscopic structure and conformations of reference polymer melts described by a microscopic model. The microscopically resolved samples retain all generic features affecting polymer topology and provide, therefore, reliable reference data on knots. We compare characteristic knotting properties in mesoscopic and microscopically resolved melts for different cases of chain stiffness.