34 research outputs found
Innovations in Corneal Crosslinking.
No full textPURPOSE
Corneal Crosslinking (CXL) strengthens the keratoconus cornea and prevents further disease progression. Modified crosslinking protocols and different riboflavin solutions have been proposed to optimize the procedure and improve treatment success.
METHODS
PubMed research of relevant publications and report of own experiences with different CXL protocols.
RESULTS
Accelerated CXL shows comparable efficiency with shorter surgery time and similar complication rates. Customized CXL provides improved results with faster epithelial healing. CXL in a hyperoxic environment seems to be a safe and effective transepithelial alternative with presumably less complications and fewer side effects. Thin corneas (<400 µm) can be treated safely by corneal swelling using hypoosmolar riboflavin solutions and reducing the applied UV-energy. The combination of CXL with photorefractive keratectomy (PRK) can be considered in patients with contact lens intolerance improving visual acuity, however, with increased risk of visual loss compared to CXL alone. Two-Photon (2Ph) CXL is a promising new technology enabling three-dimensional CXL.
DISCUSSION
Recently developed CXL protocols offer advantages over the standard "Dresden-protocol" and should be considered in patients with progressive keratectasia
Biomechanical Response After Corneal Cross-linking With Riboflavin Dissolved in Dextran Solution Versus Hydroxypropyl Methylcellulose
No full textPurpose: To evaluate corneal stiffening in porcine eyes induced by corneal cross-linking (CXL) using riboflavin dissolved in either aqueous dextran or hydroxypropyl methylcellulose (HPMC) solution.
Methods: Fifty-one porcine corneas were divided into three groups of 17 each. After deepithelialization, the first (Dresden) group was treated for 30 minutes with 0.1% riboflavin (riboflavin-5-monophosphate in 0.9% NaCl) dissolved in hypertonic 20% dextran and the second (HPMC) group for 30 minutes with isotonic solution containing 0.1% riboflavin and 1.1% HPMC. Thereafter, corneas of both groups were irradiated using 5.4 J/cm2 (irradiance of 9 mW/cm2 for 10 minutes; 10*9). After CXL, all corneas were kept in an isotonic 16% dextran bath for 2 hours to obtain an equal hydration state. The third group served as the control group. Stress-strain measurements were performed on 5-mm-wide strips. Corneal thickness was monitored throughout the entire course of the experiments.
Results: The required stress for a 10% strain was increased by 83% in the Dresden group and 35% in the HPMC group compared to the control group. Resultant Young's modulus (at 10% strain) was 2.53 ± 0.73, 1.87 ± 0.50, and 1.47 ± 0.44 Pa for the Dresden, HPMC, and control groups, respectively. The differences between the Dresden and HPMC groups (P = .006), the Dresden and control groups (P < .001), and the HPMC and control groups (P = .014) were statistically significant. Pachymetry measurements showed a significantly increased corneal thickness after application of HPMC compared with the Dresden group (P = .002) and control group (P = .041).
Conclusions: The biomechanical stiffening of the cornea by CXL can be achieved using dextran- and HPMC-based riboflavin solutions in porcine corneas with an application time of 30 minutes. Dextran-based riboflavin solutions seem to induce a slightly stronger biomechanical response in this setting. HPMC solutions induce less thinning than dextran solutions
The Digital Forensics 2023 dataset - DF2023
No full textFor a detailed description of the DF2023 dataset, please refer to:
@inproceedings{Fischinger2023DFNet,
title={DF2023: The Digital Forensics 2023 Dataset for Image Forgery Detection},
author={David Fischinger and Martin Boyer},
journal={The 25th Irish Machine Vision and Image Processing conference. (IMVIP)},
year={2023}
}
DF2023 is a dataset for image forgery detection and localization. The training and validation datasets contain 1,000,000/5,000 manipulated images (and the ground truth masks).
The DF2023 training dataset comprises:
100K forged images produced by removal (inpainting) operations
200K images produced by enhancement modifications
300K copy-move manipulated images and
400K spliced images
=== Naming convention ===
The naming convention of DF2023 encodes information about the applied manipulations. Each image name has the following form:
COCO_DF_0123456789_NNNNNNNN.{EXT} (e.g. COCO_DF_E000G40117_00200620.jpg)
After the identifier of the image data source ("COCO") and the self-reference to the Digital Forensics ("DF") dataset, there are 10 digits as placeholders for the manipulation. Position 0 defines the manipulation types copy-move, splicing, removal, enhancement ([C,S,R,E]). The following digits 1-9 represent donor patch manipulations. For positions [1,2,7,8] (resample, flip, noise and brightness), a binary value indicates if this manipulation was applied to the donor image patch. Position 3 (rotate) indicates by the values 0-3 if the rotation was executed by 0, 90, 180 or 270 degrees. Position 4 defines if BoxBlur (B) or GaussianBlur (G) was used. Position 5 specifies the blurring radius. A value of 0 indicates that no blurring was executed. Position 6 indicates which of the Python-PIL contrast filters EDGE ENHANCE, EDGE ENHANCE MORE, SHARPEN, UnsharpMask or ImageEnhance (values 1-5) was applied. If none of them was applied, this value is set to 0. Finally, position 9 is set to the JPEG compression factor modulo 10, a value of 0 indicates that no JPEG compression was applied. The 8 characters NNNNNNNN in the image name template stand for a running number of the images.
=== Terms of Use / Licence ===
The DF2023 dataset is based on the MS COCO dataset. Therefore, rules for using the images form MS COCO apply also for DF2023:
Images
The COCO Consortium does not own the copyright of the images. Use of the images must abide by the Flickr Terms of Use. The users of the images accept full responsibility for the use of the dataset, including but not limited to the use of any copies of copyrighted images that they may create from the dataset.This work was co-funded by the European Union, Project 101083573 — GADMO -------
Please cite:
Fischinger, D. and Boyer, M. (2023). DF2023: The digital forensics 2023 dataset
for image forgery detection. IMVIP - 25th Irish Machine Vision and Image Processing conference
Customized Corneal Cross-linking: One-Year Results.
No full textPURPOSE
To compare the efficacy of customized corneal cross-linking (CXL) with standard CXL.
DESIGN
Prospective, nonrandomized comparative clinical study.
METHODS
In a prospective study at the Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Zurich, Switzerland, 40 eyes of 40 patients with documented progressive primary keratoconus were treated with customized CXL (n = 20) or standard CXL (n = 20) and followed for 1 year. Customized irradiation patterns had an energy fluence of 9 mW/cm(2) and total energy levels ranging from 5.4 J/cm(2) up to 10 J/cm(2) and were centered on the maximum of the posterior float. The control group received homogenous irradiation with a fluence of 9 mW/cm(2) and a total energy of 5.4 J/cm(2). Scheimpflug tomographies, endothelium cell count, best spectacle-corrected visual acuity (BSCVA), and anterior segment optical coherence tomography (OCT) were compared preoperatively and 1 year postoperatively.
RESULTS
Pachymetry and ΔKmax showed significant changes 1 year postoperatively within each group. Epithelial healing time, ΔKmax, and regularization index (RI) were significantly better in the customized CXL group. Two out of 19 eyes (11%) in the standard group but 7 out of 19 eyes (37%) in the customized CXL group showed a flattening of 2 or more diopters (P = .03). The RI was 5.2 ± 2.7 D in the customized group vs 4.1 ± 3.1 D in the control group (P = .03). Statistically significant correlations between RI and preoperative Kmax, preoperative pachymetry, and preoperative posterior float were found only in the customized group.
CONCLUSIONS
Customized CXL seems to be as safe as standard CXL with stronger flattening in Kmax and RI, and a faster epithelial healing period
Corneal crosslinking (CXL) with 18-mW/cm irradiance and 5.4-J/cm radiant exposure-early postoperative safety.
No full textPURPOSE
To investigate safety of accelerated corneal crosslinking during the first postoperative month.
METHODS
In this retrospective study, 76 eyes of 60 patients with verified progressive keratectasia were enrolled in this study and followed for 1 month after accelerated CXL (18 mW/cm for 5 min, radiant exposure 5.4 J/cm) (A-CXL(5*18)). Preoperatively, objective refraction, slit lamp inspection, and corneal tomography were performed. Early postoperative slit lamp examinations were performed on days 1 and 4. At 1 month, objective refraction, slit lamp inspection, and corneal tomography were performed.
RESULTS
Gender distribution was m:f = 55:21, OD:OS was 40:36, and the average age was 26.5 ± 8.6 years at surgery. Only 71 of the 76 eyes completed the 1-month follow-up, indicating a dropout rate of 6.6%. In 7.0% (n = 5), sterile infiltrates were observed; 5.6% of eyes (n = 4) showed delayed epithelial healing (> 4 days) in 2.8% (n = 2); an infection occurred and in 1 eye (1.4%), a stromal scar was detected; no other complications, neither a loss of two or more Snellen lines at 1 month postoperatively, were observed. As a risk factor for sterile infiltrates, thin preoperative pachymetry could be identified (p = 0.027).
CONCLUSIONS
This study revealed no difference in early postoperative safety between CXL using 18 mW/cm and standard corneal CXL. Thinner preoperative pachymetry could be identified predicting a higher rate of postoperative sterile infiltrates
Comparison of Corneal Riboflavin Gradients Using Dextran and HPMC Solutions.
No full textPURPOSE
To determine the riboflavin concentration gradient in the anterior corneal stroma when using hydroxypropyl methylcellulose (HPMC) or dextran as the carrier agent.
METHODS
Four different groups of porcine corneas (5 each) were compared regarding the riboflavin concentration in the anterior stroma. Prior to all experiments, stable hydration conditions were established for the corresponding solution. The dextran groups were treated with 0.1% riboflavin in 20% dextran for 10 and 30 minutes and the HPMC groups with 0.1% riboflavin in 1.1% HPMC for 10 and 30 minutes. After imbibition, nonlinear microscopy and consecutive image analysis were used to determine two-photon fluorescence intensities. To determine the riboflavin concentration, corneas were saturated and measured a second time by two-photon microscopy. With this measurement, a proper correction for absorption and scattering could be performed. Ultraviolet-A (UVA) transmission was measured after the application time for each group.
RESULTS
Riboflavin concentration decreased with increasing depth and increased with longer application times in all groups. Comparing the dextran for 30 minutes and HPMC for 10 minutes groups, a significantly higher stromal riboflavin concentration was found within the most anterior 70 µm in the dextran group for 30 minutes, whereas deeper than 260 µm HPMC-assisted imbibition for 10 minutes yielded higher concentrations. In dextran-treated corneas, values obtained from pachymetry were substantially reduced, whereas HPMC-assisted imbibition led to a decent swelling. UVA transmission values were higher in dextran-assisted imbibition than in HPMC-assisted imbibition.
CONCLUSIONS
Stromal riboflavin gradients are similar when applied in dextran for 30 minutes and HPMC for 10 minutes. When using HPMC solutions, a shallower cross-linked volume is expected due to a higher corneal hydration. [J Refract Surg. 2016;32(12):798-802.]
Characteristics of surgically induced astigmatism after standardized microincisional cataract surgery with a superior limbal incision.
No full textPURPOSE
To determine 1) if measurements of surgically induced astigmatism (SIA) as measured by keratometry (K) and total keratometry (TK) differ 2) if SIA affects the magnitude and/or meridian of keratometric astigmatism 3) if SIA evolves over time.
SETTING
Tertiary care center.
DESIGN
Retrospective data analysis.
METHODS
A swept-source OCT (SS-OCT) biometry dataset (IOLMaster700) consisting of 498 eyes (327 patients) from a tertiary care center was analyzed. For all eyes preoperative and postoperative biometric measurements at 1-, 3-, and 6-months postoperative visits were considered for vector analysis of SIAK and SIATK.
RESULTS
Centroids in right and left eyes were 0.26 dpt @5°/ 0.31 dpt @1° for SIAK and 0.27 dpt @4°/ 0.34 dpt @1° for SIATK. Centroids for difference vectors (DV) K-TK in right and left eyes were 0.02 dpt @ 176°/ 0.03 dpt @6°. The mean SIA magnitudes in right and left eyes were 0.48±0.41 dpt and 0.50±0.37 dpt for SIAK and 0.53±0.42 dpt and 0.54±0.40 dpt for SIATK. In eyes with ATR astigmatism, an increase in postoperative astigmatism magnitude was more common than a decrease. More than 30% of eyes showed changes in the meridian of more than 15°.
CONCLUSION
Overall, we observed differences in K- and TK-derived SIA, and changes in SIA magnitude over time. For post-surgical interventions, postoperative astigmatism meridian values should be measured to base treatments. Astigmatism magnitude showed a tendency to decrease for steep-meridian incisions and to increase in flat-meridian incisions
Considerations on the calculation of multifocal duet implantation in a monovision scenario for the correction of presbyopia – a case example
No full textFrom Malevich’s square to Fischinger to abstract animation in the digital age
No full textThe Genre of abstract animation is investigated from a practice-based perspective by tracing the theme o Malevich’s abstract square from painting to digital animation in the contemporary context. Beginning with the avant-garde artist Malevish’s paintings ’White on White’ and ‘Black Square’ as ultimate statements on non-representational form that defines the term ‘abstract’ in art, the basic image of the (Malevich) square is traceable through to the cinematic moving-image. The square reappears in colourful movement and rhythm in the early abstract animation films by pioneering artist-filmmaker Oskar Fischinger. The Square is reiterated, in direct reference to Malevich, in contemporary abstract animations. From its early beginnings abstraction in animation ran parallel to abstraction in the visual arts, yet the unique form of abstract animation has continued consistently to the present day alongside other forms of animation. Reflecting the blurred boundaries between painting and animation, as in Fischinger’s pioneering work, abstract animation has persisted throughout the developments of animation processes, techniques and technologies, utilising film-based as well as current digital technologies. Contemporary auteur, abstract animation examples that make direct reference to the Malevich square, in this discussion include ‘Nemumel’ (2014, Sawako, Japan), ‘Black Rectangle’ (2013, Rhyane Vermette, USA) and ‘Interior’ by the author ( 2013, Sabrina Schmid, UK). Through the particular imagery, concepts and processes, these abstract animations reassert or revisit some of the ‘purist’ views on animation where the fundamental elements of animation are seen as composed purely of basic shapes, forms, colours, rhythm, timing and movement, synchronised to sound, to evoke an aesthetic experience in the viewer. Further important components within this discourse are the expanding platforms for the screening and exhibition of abstract animation, namely specialised abstract festivals, festivals including focused abstract programs, international touring programs and a growing resource of abstract animation available through online archives and collections
HEALTH RESORT OPATIJA AND ITS HEADMASTER PROFESSOR JULIUS GLAX (1846 –1922)
No full textU članku se opisuje profesor Julius Glax (1846.–1922.) kao jedna od vodećih osoba zaslužnih za razvoj Opatije u zdravstveno i kupališno središte. Julius Glax bio je opatijski liječnik, glavni liječnik Sanatorija Južnih željeznica i austrijskog Crvenog križa. Uz to je bio član Povjerenstva Zdravstvenog centra u Opatiji, predsjedavatelj različitih društava i autor stručnih članaka i knjiga.
Kao ravnatelj Zdravstvenog centra u Opatiji (1899.–1919.) nadzirao je i upravljao izgradnjom infrastrukture potrebne za razvoj Opatije iz ribarskog mjesta u austrijsku Nicu.This article presents professor Julius Glax as one of the leading figures in the development of Opatija 'into a health and seaside resort. In Opatija he was a practicing physician, head physician of Southern Railways sanatoriums, head physician of the Austrian society White Cross, member of Opatija health resort commission, chairman of various societies, and author of professional articles and books. As the director of the health resort in Opatija (1899-1919), he supervised all management and logistics necessary for the development of this seaside settlement into a Austrian Nice
