Assessment of the microvasculature in poppers maculopathy.

PURPOSE: To investigate a possible microvascular component of poppers maculopathy (PMP) using optical coherence tomography angiography (OCTA). METHODS: Twelve patients suffering from poppers maculopathy were included. Health records, optical coherence tomography (OCT), and OCTA data was gathered and compared to a healthy control group (HC). PMP lesion type was determined by manifestation in OCT. OCTA-based evaluation of retinal vascular plexus and choriocapillaris (CC) was executed. Vessel density (VD) and vessel length density (VLD) in superficial and deep capillary plexus (SCP, DCP), as well as flow deficits (FD), within the foveal avascular zone (FAZ) in CC were assessed. RESULTS: Median age of PMP patients was 40 (min 24; max 64) years, all male. Eleven patients presented with ellipsoid zone-type lesions; one patient showed a vitelliform-type lesion. No qualitative microvascular changes between PMP patients and HC were identified. Quantitative values for VD and VLD of SCP and DCP did not differ in between the two groups. The analysis of FDs in CC showed no deviation from PMP patients to HC. CONCLUSIONS: No vascular anomalies in qualitative and quantitative analysis in OCTA were detected in PMP patients. The constitution of the CC within FAZ of PMP patients does not differ from HC when assessed as FD.

Long-term follow-up of lamellar macular holes and pseudoholes over at least 5 years.

PURPOSE: To assess morphological and functional changes of lamellar macular holes and pseudoholes with or without vitrectomy and membrane peeling with at least 5 years follow-up. METHODS: Retrospective study of 73 eyes with lamellar macular hole (LH, n = 28), macular pseudohole (PH, n = 31), and pseudohole with cleaved edges (cleavedPH, n = 14). Forty-six eyes were merely observed without vitreoretinal intervention (observation group), and 27 eyes underwent vitrectomy with membrane peeling (vitrectomy group). Outcome measures were best corrected visual acuity (BCVA) and morphological retinal parameters evaluated with optical coherence tomography (TD-OCT and SD-OCT). RESULTS: Mean follow-up was 8.3 years (5-12); mean age was 67 years (46-84). In the observation group, median BCVA (logMAR) at first exam was 0.2 (LH), 0.1 (PH), 0.2 (cleavedPH) and at last exam 0.3 (LH, p = 0.02), 0.2 (PH), 0.15 (cleavedPH). In the vitrectomy group, median BCVA at first exam was 0.4 (LH), 0.3 (PH), 0.25 (cleavedPH); before vitrectomy BCVA was 0.5 (LH), 0.35 (PH), 0.35 (cleavedPH); and at last exam BCVA increased to 0.3 (LH), 0.2 (PH, p < 0.05), 0.1 (cleavedPH, p < 0.05). At last exam, BCVA of LH was significantly worse compared to PH and cleavedPH. In the observation group, 6 of 29 eyes with PH or cleavedPH showed a spontaneous resolution of the epiretinal membrane with improvement of the foveal contour. Nine of 16 eyes with LH and 2/20 eyes with PH presented lamellar hole-associated epiretinal proliferation (LHEP) in SD-OCT. CONCLUSIONS: LH, PH, and cleavedPH are often stable over a very long time. LH tends to worse visual function compared to PH and cleavedPH. A spontaneous separation of epiretinal membranes in the long-term is not uncommon. Vitreoretinal intervention should be considered in cases with significant visual loss or functional and morphological progression.

Functionalization of a self-assembled monolayer driven by low-energy electron exposure.

Self-assembled monolayers (SAMs) of 10-undecene-1-thiol on Au were functionalized with nitrogen-containing groups using an approach in which multilayer ammonia (NH(3)) films were deposited at low temperature onto the SAMs and subsequently exposed to 15 eV electrons. The result of this process was investigated after removal of the remaining NH(3) by annealing to room temperature using high-resolution electron energy loss spectroscopy (HREELS) and X-ray photoelectron spectroscopy (XPS). HREELS shows that the CC double bonds disappear during electron exposure, while XPS gives evidence that about 25% of the terminal double bonds of the SAM were functionalized. Also, XPS shows that a sufficiently thick NH(3) layer protects the underlying SAM from electron-induced damage. The process suggested here thus represents a particularly gentle approach to the functionalization of ultrathin molecular layers. Thermal desorption spectrometry (TDS) and electron-stimulated desorption (ESD) experiments on condensed layers of NH(3) reveal production of N(2) but show that significant amounts of the initial NH(3) as well as N(2) produced during electron exposure desorb. Hydrogen released upon formation of N(2) is held responsible for the reduction of double bonds and protection of the SAMs from damage.

A Novel Quantitative Assessment Method of Disease Activity in Susac's Syndrome Based on Ultra-Wide Field Imaging.

PURPOSE: Susac's syndrome (ScS) is a rare, potentially life-threatening auto-immune disease. Ophthalmic imaging can depict characteristic branch retinal arteriolar occlusions (BRAO) and arterial wall hyperfluorescences that form one of the three diagnostic pillars of this condition. We aim to demonstrate that ophthalmological ultrawide-field (UWF) imaging allows for a qualitative and quantitative assessment in ScS, with application in diagnostics, monitoring of treatment response, and titration of therapy. METHODS: In seven ScS patients (♀:♂ = 2:5), with a median age of 36 years, range 18 to 57 years, serial ultrawide-field fluoresceine angiography (UWF-FA) studies were performed, with adjunctive wide-field optical coherence tomography angiography analyses (WF-OCTA) in five patients. Mean follow-up was 12.5 months, range 1 to 46 months. RESULTS: In all seven patients, BRAO and arterial wall hyperfluorescences were present in UWF-FA and calculated as a quantitative score of disease activity in fluorescein angiography (DA-FA) during follow-up visits. Treatment response was accessible in follow-up imaging as partial reperfusion of retinal vessels, resolution of arterial wall hyperfluorescences and consequently, in reduction of DA-FA score. While qualitative analysis of WF-OCTA provided further information about retinal micro-perfusion, quantitative analysis did not demonstrate a vectored treatment response as it was accessible in FA. CONCLUSION: DA-FA score, as a comprehensive disease activity parameter in ScS has potential to facilitate optimal communication between subspecialties and thereby treatment success.

Dissociative electron attachment to gas-phase formamide.

Dissociative electron attachment (DEA) to gaseous formamide, HCONH(2), has been investigated in the energy range between 0 eV and 18 eV using a crossed electron/molecule beam technique. The negative ion fragments have been comprehensively monitored and assigned to molecular structures by comparison with the results for two differently deuterated derivatives, namely 1D-formamide, DCONH(2), and N,N,D-formamide, HCOND(2). The following products were observed: HCONH(-), CONH(2)(-), HCON(-), OCN(-), HCNH(-), CN(-), NH(2)(-)/O(-), NH(-), and H(-). NH(2)(-) was also separated from O(-) by using high-resolution negative ion mass spectrometry. Four resonant dissociation channels can be resolved, the strongest ones being located between 2.0 and 2.7 eV and between 6.0 and 7.0 eV. CN(-) as the most abundant fragment and HCONH(-) are the dominant products of the first of these two resonances. The most important products of the latter resonance are NH(2)(-), CN(-), H(-), CONH(2)(-), and OCN(-). It is thus found that the loss of neutral H is a site-selective process, dissociation from the N site taking place between 2.0 and 2.7 eV while dissociation from the C site occurs between 6.0 and 7.0 eV. The suitability of these reactions and thus of formamide as an agent for electron-induced surface functionalisation is discussed.

The auxin-insensitive bodenlos mutation affects primary root formation and apical-basal patterning in the Arabidopsis embryo.

In Arabidopsis embryogenesis, the primary root meristem originates from descendants of both the apical and the basal daughter cell of the zygote. We have isolated a mutant of a new gene named BODENLOS (BDL) in which the primary root meristem is not formed whereas post-embryonic roots develop and bdl seedlings give rise to fertile adult plants. Some bdl seedlings lacked not only the root but also the hypocotyl, thus resembling monopteros (mp) seedlings. In addition, bdl seedlings were insensitive to the auxin analogue 2,4-D, as determined by comparison with auxin resistant1 (axr1) seedlings. bdl embryos deviated from normal development as early as the two-cell stage at which the apical daughter cell of the zygote had divided horizontally instead of vertically. Subsequently, the uppermost derivative of the basal daughter cell, which is normally destined to become the hypophysis, divided abnormally and failed to generate the quiescent centre of the root meristem and the central root cap. We also analysed double mutants. bdl mp embryos closely resembled the two single mutants, bdl and mp, at early stages, while bdl mp seedlings essentially consisted of hypocotyl but did form primary leaves. bdl axr1 embryos approached the mp phenotype at later stages, and bdl axr1 seedlings resembled mp seedlings. Our results suggest that BDL is involved in auxin-mediated processes of apical-basal patterning in the Arabidopsis embryo.