830 research outputs found
Novel Technique of Transepithelial Corneal Cross-Linking Using Iontophoresis in Progressive Keratoconus
In this work, the authors presented the techniques and the preliminary results at 6 months of a randomized controlled trial (NCT02117999) comparing a novel transepithelial corneal cross-linking protocol using iontophoresis with the Dresden protocol for the treatment of progressive keratoconus. At 6months, there was a significant average improvement with an average flattening of themaximum simulated keratometry reading of 0.72\ub11.20D(P = 0.01); in addition, corrected distance visual acuity improved significantly (P = 0.08) and spherical equivalent refraction was significantly lessmyopic (P = 0.02) 6months a\u17fter transepithelial corneal cross-linkingwith iontophoresis. The novel protocol using iontophoresis showed comparable resultswith standard corneal cross-linking to halt progression of keratoconus during 6-month follow-up. Investigation of the long-term RCT outcomes are ongoing to verify the efficacy of this transepithelial corneal cross-linking protocol and to determine if it may be comparable with standard corneal cross-linking in themanagement of progressive keratoconus
Abelian Fourfolds of Weil type and certain K3 Double Planes
Double planes branched in 6 lines give a famous example of K3 surfaces. Their
moduli are well understood and related to abelian fourfolds of Weil type. We
compare these two moduli interpretations and in particular divisors on the
moduli spaces. On the K3 side, this is achieved with the help of elliptic
fibrations. We also study the Kuga-Satake correspondence on these special
divisors.Comment: 48 pages, 4 figures; v3: final version with several additions
suggested by the refere
Investigation of adaptive optics imaging biomarkers for detecting pathological changes of the cone mosaic in patients with type 1 diabetes mellitus
Purpose
To investigate a set of adaptive optics (AO) imaging biomarkers for the assessment of
changes of the cone mosaic spatial arrangement in patients with type 1 diabetes mellitus
(DM1).
Methods
16 patients with 20/20 visual acuity and a diagnosis of DM1 in the past 8 years to 37 years
and 20 age-matched healthy volunteers were recruited in this study. Cone density, cone
spacing and Voronoi diagrams were calculated on 160x160 μm images of the cone mosaic
acquired with an AO flood illumination retinal camera at 1.5 degrees eccentricity from the
fovea along all retinal meridians. From the cone spacing measures and Voronoi diagrams,
the linear dispersion index (LDi) and the heterogeneity packing index (HPi) were computed
respectively. Logistic regression analysis was conducted to discriminate DM1 patients without
diabetic retinopathy from controls using the cone metrics as predictors.
Results
Of the 16 DM1 patients, eight had no signs of diabetic retinopathy (noDR) and eight had
mild nonproliferative diabetic retinopathy (NPDR) on fundoscopy. On average, cone density,
LDi and HPi values were significantly different (P<0.05) between noDR or NPDR eyes
and controls, with these differences increasing with duration of diabetes. However, each
cone metric alone was not sufficiently sensitive to discriminate entirely between membership
of noDR cases and controls. The complementary use of all the three cone metrics in
the logistic regression model gained 100% accuracy to identify noDR cases with respect to
controls.
PLOS ONE | DOI:10.1371/journal.pone.0151380 March 10, 2016 1 / 14
OPEN ACCESS
Citation: Lombardo M, Parravano M, Serrao S,
Ziccardi L, Giannini D, Lombardo G (2016)
Investigation of Adaptive Optics Imaging Biomarkers
for Detecting Pathological Changes of the Cone
Mosaic in Patients with Type 1 Diabetes Mellitus.
PLoS ONE 11(3): e0151380. doi:10.1371/journal.
pone.0151380
Editor: Knut Stieger, Justus-Liebig-University
Giessen, GERMANY
Received: December 17, 2015
Accepted: February 27, 2016
Published: March 10, 2016
Copyright: © 2016 Lombardo et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any
medium, provided the original author and source are
credited.
Data Availability Statement: All relevant data are
within the paper and its Supporting Information files.
Funding: Research for this work was supported by
the Italian Ministry of Health (5x1000 funding), by the
National Framework Program for Research and
Innovation PON (grant n. 01_00110) and by
Fondazione Roma. The funders had no role in study
design, data collection and analysis, decision to
publish, or preparation of the manuscript. Vision
Engineering Italy srl funder provided support in the
form of salaries for author GL, but did not have any
Conclusion
The present set of AO imaging biomarkers identified reliably abnormalities in the spatial
arrangement of the parafoveal cones in DM1 patients, even when no signs of diabetic retinopathy
were seen on fundoscopy
Heroin-piracetam mixture: suggested mechanisms of action and risks of misinterpretation for drug users
Piracetam is a positive allosteric modulator of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor that has been frequently used in the treatment of cognitive disorders. Press and internet reports indicate that the use of piracetam, as a heroin adulterant, has spread rapidly in some countries, especially in Asia and Europe. Its use, as adulterant, is believed to produce more profound desirable effects, while decreasing hangover. Recent surveys demonstrated that piracetam protects neurons from heroin-induced apoptosis. The protective role of this adulterating substance may be related to restoration of beta-endorphin levels and to its neuroprotective effects. The aim of this paper is to review the relevant literature and suggest the main hypothetical mechanisms that justify its use as a heroin adulterant, try to understand if its use could help people who want to come off heroin by reducing withdrawal symptoms and, finally, give useful information that permit us to understand why drug trafficking organisations started to use piracetam as heroin adulterant
All-Optical Method to Assess Stromal Concentration of Riboflavin in Conventional and Accelerated UV-A Irradiation of the Human Cornea.
PURPOSE. We investigated the concentration of riboflavin in human donor corneas during corneal cross-linking using two-photon optical microscopy and spectrophotometry. METHODS. Eight corneal tissues were de-epithelialized and soaked with 20% dextran-enriched 0.1% riboflavin solution for 30 minutes. After stromal soaking, three tissues were irradiated using a 3 mW/cm(2) UV-A device for 30 minutes and three tissues irradiated using a 10 mW/cm2 device for 9 minutes. Two additional tissues were used as positive controls. A Ti:sapphire laser at 810 nm was used to perform two-photon emission fluorescence (TPEF) and second harmonic generation axial scanning measurements in all specimens before and after stromal soaking and after UV-A irradiation. In addition, spectrophotometry was used to collect the absorbance spectra of each tissue at the same time intervals. Analysis of the absorbance spectra and TPEF signals provided measures of the concentration depth profile of riboflavin in corneal stroma. RESULTS. After stromal soaking, the average peak concentration of riboflavin (0.020% +-0.001%) was found between a stromal depth of 100 and 250 lm; the concentration of riboflavin was almost constant up to 320 6 53 lm depth, then decreased toward the endothelium, though riboflavin was still enriched in the posterior stroma (0.016%% 6 0.001%). After conventional and accelerated UV-A irradiation, the concentration of riboflavin decreased uniformly 87% 6 2% and 67% 6 3% (P < 0.001), respectively. CONCLUSIONS. The combined use of two-photon optical microscopy and spectrophotometry provides relevant information for investigating the concentration of riboflavin in corneal stroma. The method can assist with the assessment of novel riboflavin formulations and different UV-A irradiation protocols
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