Internet-of-Things (IoT) Platform for Road Energy Efficiency Monitoring.

The road transportation sector is a dominant and growing energy consumer. Although investigations to quantify the road infrastructure's impact on energy consumption have been carried out, there are currently no standard methods to measure or label the energy efficiency of road networks. Consequently, road agencies and operators are limited to restricted types of data when managing the road network. Moreover, initiatives meant to reduce energy consumption cannot be measured and quantified. This work is, therefore, motivated by the desire to provide road agencies with a road energy efficiency monitoring concept that can provide frequent measurements over large areas across all weather conditions. The proposed system is based on measurements from in-vehicle sensors. The measurements are collected onboard with an Internet-of-Things (IoT) device, then transmitted periodically before being processed, normalized, and saved in a database. The normalization procedure involves modeling the vehicle's primary driving resistances in the driving direction. It is hypothesized that the energy remaining after normalization holds information about wind conditions, vehicle-related inefficiencies, and the physical condition of the road. The new method was first validated utilizing a limited dataset of vehicles driving at a constant speed on a short highway section. Next, the method was applied to data obtained from ten nominally identical electric cars driven over highways and urban roads. The normalized energy was compared with road roughness measurements collected by a standard road profilometer. The average measured energy consumption was 1.55 Wh per 10 m. The average normalized energy consumption was 0.13 and 0.37 Wh per 10 m for highways and urban roads, respectively. A correlation analysis showed that normalized energy consumption was positively correlated to road roughness. The average Pearson correlation coefficient was 0.88 for aggregated data and 0.32 and 0.39 for 1000-m road sections on highways and urban roads, respectively. An increase in IRI of 1 m/km resulted in a 3.4% increase in normalized energy consumption. The results show that the normalized energy holds information about the road roughness. Thus, considering the emergence of connected vehicle technologies, the method seems promising and can potentially be used as a platform for future large-scale road energy efficiency monitoring.

Relationship between Diabetic Retinopathy and Primary Open-Angle Glaucoma: A Systematic Review and Meta-Analysis.

BACKGROUND: Pathophysiological overlaps exist between diabetes and primary open-angle glaucoma (POAG) and presence of diabetes increases the risk of POAG. Considering that diabetic retinopathy (DR) is an ocular complication of diabetes, one could speculate that DR as a severity measure may associate with or even predict POAG. Given that POAG is asymptomatic in early stages, an association to DR may prove clinically important and facilitate an earlier diagnosis of POAG. OBJECTIVES: The aim of the study was to investigate if DR is associated with and predictive of POAG. METHOD: We systematically searched 11 literature databases on May 12, 2021. We screened a total of 1,535 records and found six studies eligible for qualitative and quantitative analysis. Two independent authors reviewed the studies, extracted data, and evaluated risk of bias within individual studies. Studies were reviewed qualitatively, and meta-analyses were made based on the odds ratios (ORs) with 95% confidence intervals (CI) of the association between DR and POAG using the random-effects model. Subgroup analyses were made on the association between subtypes of DR and POAG. RESULTS: Six studies (two longitudinal and four cross-sectional) were eligible for review with a total of 255,614 patients with diabetes, of which 20,483 patients had any degree of DR and 5,258 had POAG. All studies were based on patients with type 2 diabetes except one with both type 1 and type 2 patients. Any DR was not associated with POAG (OR 1.17; 95% CI: 0.58-2.35; p = 0.65). Further stratification revealed that neither cross-sectional (OR 1.00; 95% CI: 0.56-1.81, p = 0.99) nor longitudinal studies (OR 1.47; 95% CI: 0.57-3.78, p = 0.43) demonstrated an association between DR and POAG. CONCLUSIONS: We did not find convincing evidence of an associations between DR and prevalent or incident POAG.

Small-incision lenticule extraction (SMILE): outcomes of 722 eyes treated for myopia and myopic astigmatism.

PURPOSE: To study the outcomes of small-incision lenticule extraction (SMILE) for treatment of myopia and myopic astigmatism. METHODS: Retrospective study of patients treated for myopia or myopic astigmatism with SMILE, using a VisuMax(®) femtosecond laser (Carl Zeiss Meditec, Jena, Germany), at the Department of Ophthalmology, Odense University Hospital, Odense, Denmark. Inclusion criteria were corrected distance visual acuity (CDVA) of 20/25 or better before surgery and no ocular conditions other than myopia up to -10.00 diopters (D) with astigmatism up to 3.00 D. RESULTS: Of the 729 treatments, 722 were included. The spherical equivalent (SE) refraction averaged -6.82 ± 1.66 diopters (D) before surgery. After 3 months, 88 % of eyes were within ±0.50 D of the intended refraction, whilst 98 % were within ±1.00 D. The mean difference between attempted and achieved SE refraction at 3 months after surgery was -0.06 ± 0.01 D (range: -1.25 to 1.25 D). In eyes with emmetropia as target refraction (n = 362), 63 % had uncorrected distance visual acuity (UDVA) of 20/25 or better 1 day after surgery, rising to 83 % at 3 months after surgery. The average gain in CDVA from before surgery to 3 months after surgery was 0.07 ± 0.03 (logMAR). However, 12 eyes (1.6 %) lost 2 or more lines of CDVA from before surgery to 3 months postoperatively. Simultaneous treatment of up to 3.00 D of astigmatism was not associated with less predictable refractive outcomes. CONCLUSIONS: In the short term, SMILE seemed predictable, efficient, and safe for treatment of myopia and myopic astigmatism.

Four-year to seven-year outcomes of advanced surface ablation with excimer laser for high myopia.

PURPOSE: We aimed to evaluate and compare outcomes after photorefractive keratectomy with cooling (cPRK) and laser-assisted subepithelial keratectomy (LASEK) for high myopia. METHODS: This was a retrospective, single-masked follow-up study of patients treated for myopia between 2007 and 2009 with cPRK or LASEK, using a high-frequency flying-spot excimer laser with eye-tracker (MEL80; Carl Zeiss, Jena, Germany). One eye of each patient was randomly chosen for analysis. Re-treated eyes were excluded. RESULTS: Forty-six cPRK patients and 35 LASEK patients were included. Spherical equivalent averaged -7.69 ± 1.47 diopters (D) in cPRK eyes and -7.98 ± 2.06 D in LASEK eyes (p = 0.31) before surgery. The average follow-up time was 4.6 years in cPRK patients and 6.0 years in LASEK patients (p < 0.05). At final follow-up, no cPRK eyes and one LASEK eye (p = 0.46) had lost two lines of corrected distance visual acuity (CDVA). No eyes had significant haze at final follow-up, although trace haze was found in four cPRK eyes and six LASEK eyes (p = 0.44). However, at 6 weeks after surgery, zero cPRK eyes and nine LASEK eyes (p < 0.05) had significant haze. At final follow-up, 63 % of cPRK eyes and 35 % of LASEK eyes (p = 0.17) were within ±1.0 D of intended refraction. Finally, 100 % of cPRK patients and 92 % of LASEK patients (p = 0.87) were satisfied or very satisfied with the surgery at final follow-up. CONCLUSION: cPRK and LASEK seemed safe and with high patient satisfaction 4 to 7 years after surgery for high myopia. However, cPRK was more effective than LASEK in reducing initial significant corneal haze.

Central corneal sublayer pachymetry and biomechanical properties after refractive femtosecond lenticule extraction.

PURPOSE: To compare central corneal sublayer pachymetry and biomechanical properties after femtosecond lenticule extraction (FLEX) and small-incision lenticule extraction (SMILE). METHODS: A prospective, randomized, single-masked clinical trial of 35 patients treated for moderate to high myopia with FLEX in one eye and SMILE in the other. Anterior segment optical coherence tomography imaging (Heidelberg Spectralis; Heidelberg Engineering GmbH, Heidelberg, Germany) was used to measure central corneal thickness (CCT) and epithelial, flap/cap, and residual stromal bed thickness centrally. The Ocular Response Analyzer (Reichert Ophthalmic Instruments, Buffalo, NY) was used to assess corneal hysteresis (CH) and corneal resistance factor (CRF). Patients were examined before and 6 months after surgery. RESULTS: Mean decrease in CCT was 105 µm in FLEX-treated eyes and 106 µm in SMILE-treated eyes (P = .70), which is equivalent to approximately 14 µm/diopters corrected. Mean central epithelial thickness increased 7 ± 6 µm in FLEX-treated eyes and 6 ± 5 µm in SMILE-treated eyes (P = .64). Achieved mean flap/cap thickness was 4 ± 6 µm from the expected thickness in FLEX-treated eyes and 4 ± 9 µm in SMILE-treated eyes (P = .37). CH was reduced 2.7 ± 1.3 mm Hg in FLEX-treated eyes and 3.3 ± 1.2 mm Hg in SMILE-treated eyes (P = .08). CRF was reduced 4.5 ± 1.2 mm Hg in FLEX-treated eyes and 4.6 ± 1.2 mm Hg in SMILE-treated eyes (P = .71). CH and CRF were highly correlated with CCT, but not patient age. CONCLUSIONS: In this paired-eye study, the flap-based FLEX and cap-based SMILE resulted in almost identical changes in central corneal sublayer pachymetry and biomechanical properties for moderate to high myopia 6 months after treatment.

Corneal biomechanical properties after LASIK, ReLEx flex, and ReLEx smile by Scheimpflug-based dynamic tonometry.

PURPOSE: To evaluate corneal biomechanical properties after LASIK, ReLEx flex, and the flap-free procedure ReLEx smile by Scheimpflug-based dynamic tonometry (Corvis ST) and non-contact differential tonometry (Ocular Response Analyzer, ORA). METHODS: Patients treated for high myopia (-10.5 to -5.5 diopters, spherical equivalent refraction) more than one year previously at Aarhus University Hospital were included. Treatments comprised LASIK (35 eyes), ReLEx flex (31 eyes), and ReLEx smile (29 eyes). A control group included 31 healthy eyes. Cornea-compensated IOP (IOPcc), corneal hysteresis (CH), and corneal resistance factor (CRF) were measured with ORA. Corneal applanation and deformation were registered with Corvis ST during an air-pulse. RESULTS: Multiple linear regression analysis showed that CH and CRF were significantly lower after all keratorefractive procedures compared to healthy controls (p < 0.05). No significant differences were observed in CH or CRF between the keratorefractive groups. Corvis ST showed no differences in radius at highest concavity (HC radius), time until first applanation (A1 Time), time until second applanation (A2 Time), and deflection length at highest concavity (HC deflection length) between groups. LASIK treated eyes had significantly shorter time until highest concavity than eyes treated with ReLEx smile (HC Time, p = 0.01). The A1 deflection length was significantly shorter in the keratorefractive groups compared to the healthy controls (p < 0.05). CONCLUSIONS: Keratorefrative procedures alter the corneal biomechanical properties with regard to corneal hysteresis and corneal resistant factor. The flap-based LASIK and ReLEx flex and the flap-free ReLEx smile result in similar reduction in corneal biomechanics when evaluated by Corvis ST and ORA.

Lack of stereopsis does not reduce surgical performance but prolongs the learning curve of vitreoretinal surgery.

PURPOSE: To investigate whether individuals with long-term reduced stereopsis were able to obtain the same level of surgical skills in simulated vitreoretinal surgery on the Eyesi Surgical Simulator as individuals with normal stereopsis. METHODS: Twenty-four medical students were recruited and divided into two groups according to their degree of stereopsis: Group 1 (n = 12) included subjects with normal stereopsis (60 arcsec or lower) and Group 2 (n = 12) included subjects with reduced stereopsis (120 arcsec or higher). Stereopsis was tested using the TNO test (Lameris Ootech BV, Nieuwegein, the Netherlands). The participants were trained in virtual reality-simulated vitreoretinal surgery and continuously measured using a test with solid validity evidence and a pre-defined pass-fail score. All data were analysed using the Wilcoxon rank sum test. RESULTS: We observed no differences in overall performance scores for any of the four modules. The participants with reduced stereopsis used 5.8 more attempts in bimanual training (p = 0.04), 8.8 more attempts in removal of posterior hyaloid (p = 0.04), 9.1 more attempts in navigation training (p = 0.20) and 0.3 fewer attempts in removal of internal limiting membrane (p = 0.69). CONCLUSION: The final performance scores on the Eyesi Surgical Simulator were independent of the degree of stereopsis. However, the number of attempts to achieve the pre-defined pass-fail score increased significantly with reduced stereopsis in two of four modules. These results indicate that a high degree of stereopsis is not necessary to become proficient in microsurgery but may prolong the learning curve.

Long-term outcomes of photorefractive keratectomy for low to high myopia: 13 to 19 years of follow-up.

PURPOSE: To evaluate long-term outcomes after photorefractive keratectomy (PRK). METHODS: A retrospective follow-up study of patients who received PRK at 5.0- to 6.5-mm optical zones, using the Summit broad beam excimer laser (Summit Technology, Inc., Waltham, MA) at Odense University Hospital, Odense, Denmark, between 1992 and 1998. One randomly selected eye of each patient was used in the statistical analyses. Re-treated eyes were excluded. RESULTS: One hundred sixty eyes were included. Mean follow-up time was 16 years (range: 13 to 19 years). Mean preoperative spherical equivalent was -4.84 ± 2.95 diopters (D) (range: -20.25 to -1.25 D). At last follow-up examination, achieved refraction was -1.00 ± 1.56 D (range: -10.75 to +1.00 D) from attempted refraction, and the change in mean refractive error from 6 months postoperatively was less than 1.00 D. Results from a subgroup of unilateral treated patients indicated that myopic progression was the main reason for the residual refractive error. For eyes with low myopia (n = 124), the proportion of eyes within ± 1.0 D of attempted refraction was 72%, and for eyes with high myopia (-6.00 D or more, n = 36) it was 47%. Forty-five percent had uncorrected distance visual acuity of 20/20 or better at last follow-up examination. Three eyes (2%) lost two or more lines and 13 eyes (8%) gained two or more lines of corrected distance visual acuity. Fourteen percent had haze (grade 0.5 to 2). Eighty-one percent were satisfied with the surgery. CONCLUSION: PRK for low degrees of myopia seemed safe and effective up to 19 years after surgery with conventional broad beam laser ablation. Refractive predictability was significantly lower and the occurrence of haze was higher in eyes with high myopia.

Subbasal nerve morphology, corneal sensation, and tear film evaluation after refractive femtosecond laser lenticule extraction.

BACKGROUND: The purpose of this study was to compare corneal subbasal nerve morphology, corneal sensation, and tear film parameters after femtosecond lenticule extraction (FLEX) and small-incision lenticule extraction (SMILE). METHODS: A prospective, randomized, single-masked, paired-eye design clinical trial of 35 patients treated for moderate to high myopia with FLEX in one eye and SMILE in the other. In both techniques, an intrastromal lenticule was cut by a femtosecond laser and manually extracted. In FLEX, a LASIK-like flap allowed removal of the lenticule, whereas in SMILE, it was removed through a small incision. In-vivo confocal microscopy was used to acquire images of the central corneal subbasal nerve plexus, from which nerve density, total nerve number, and nerve tortuosity were analyzed. Corneal sensation was measured using Cochet-Bonnet esthesiometry. A visual analog scale, tear osmolarity, non-invasive tear film break-up time (keratograph) tear meniscus height (anterior segment OCT), Schirmer's test, and fluorescein tear film break-up time were used to evaluate tear film and ocular surface symptoms. Patients were examined before and 6 months after surgery. RESULTS: There were no statistically significant differences in baseline parameters between FLEX and SMILE (p > 0.050). With regard to changes from before to 6 months after surgery, mean reduction in subbasal nerve density was 14.22 ± 6.24 mm/mm(2) in FLEX eyes, and 9.21 ± 7.80 mm/mm(2) in SMILE eyes (p < 0.05). The total number of nerves decreased more in FLEX eyes than in SMILE eyes (p < 0.05). No change was found when comparing tortuosity (p > 0.05). Corneal sensation was reduced with 0.38 ± 0.49 cm in FLEX eyes, and 0.10 ± 0.34 cm in SMILE eyes (p < 0.01). No differences were found between FLEX and SMILE in tear film evaluation tests (p > 0.05). Significantly more patients felt postoperative foreign body sensation in the FLEX eye within the first days after surgery, as compared to the SMILE eye. CONCLUSIONS: Six months after surgery, the less invasive SMILE technique seemed better at sparing the central corneal nerves as compared to FLEX. Corneal sensation was only significantly reduced in FLEX eyes. There were no differences between FLEX and SMILE when comparing tear film evaluation tests 6 months after surgery.

A Monolayer Carbon Nitride on Au(111) with a High Density of Single Co Sites.

Carbon nitrides that expose atomically dispersed single-atom metals in the form of M-N-C (M = metal) sites are attractive earth-abundant catalyst materials that have been demonstrated in electrocatalytic conversion reactions. The catalytic performance is determined by the abundance of N-doped sites and the type of metal coordination to N, but challenges remain to synthesize pristine carbon nitrides with a high concentration of the most active sites and prepare homogeneously doped materials that allow for in-depth characterization of the M-N-C sites and quantitative evaluation of their catalytic performance. Herein, we have synthesized and characterized a well-defined monolayer carbon nitride phase on a Au(111) surface that exposes an exceedingly high concentration of Co-N4 sites. The crystalline monolayer carbon nitride, whose formation is controlled by an on-surface reaction between Co atoms and melamine on Au(111), is characterized by a dense array of 4- and 6-fold N-terminated pockets, whereof only the 4-fold pocket is found to be holding Co atoms. Through detailed characterization using scanning tunneling microscopy, X-ray photoelectron spectroscopy, and density functional theory modeling, we determine the atomic structure and chemical state of the carbon nitride network. Furthermore, we show that the monolayer carbon nitride structure is stable and reactive toward the electrocatalytic oxygen reduction reaction in alkaline electrolyte, with a quantitative performance metric that significantly exceeds comparable M-N-C-based catalyst types. The work demonstrates that high-density active catalytic sites can be created using common precursor materials, and the formed networks themselves offer an excellent platform for onward studies addressing the characteristics of M-N-C sites.

LiRA-CD: An open-source dataset for road condition modelling and research.

This data article presents the details of the Live Road Assessment Custom Dataset (LiRA-CD), an open-source dataset for road condition modelling and research. The dataset captures GPS trajectories of a fleet of electric vehicles and their time-series data from 50 different sensors collected on 230 km of highway and urban roads in Copenhagen, Denmark. Additionally, road condition measurements were collected by standard survey vehicles, which serve as high-quality reference data. The in-vehicle measurements were collected onboard with an Internet-of-Things (IoT) device, then periodically transmitted before being saved in a database. Researchers can use the dataset for prediction modelling related to standard road condition parameters such as surface friction and texture, road roughness, road damages, and energy consumption. Furthermore, researchers and pavement engineers can use the dataset as a template for future studies and projects, benchmarking the performance of different algorithms and solving problems of the same type. LiRA-CD is freely available and can be accessed at https://doi.org/10.11583/DTU.c.6659909.

Bidirectional 5-year risks of diabetic retinopathy, glaucoma and/or ocular hypertension: Results from a national screening programme.

PURPOSE: We aimed to investigate if diabetic retinopathy (DR), glaucoma and/or ocular hypertension (OHT) are prospectively linked, as previous studies have proposed cross-sectional associations, but longitudinal data from larger cohorts are lacking. METHODS: We performed a bidirectional 5 years prospective, registry-based cohort study. We extracted data from national registers, including the Danish Registry of Diabetic Retinopathy, the Danish Civil Registration System, the Danish National Patient Register and the Danish National Prescription Registry. DR level was defined by the highest level of the two eyes. Glaucoma and/or OHT was defined by diagnostic codes (H40*) or at least three redeemed prescriptions of glaucoma medication (S01E*) within 1 year. We included 205 970 persons with diabetes and 1 003 170 age- and gender-matched non-diabetes controls. Exposures were level-specific DR (i) and glaucoma and/or OHT (ii), and outcomes were hazard ratios (HRs) for 5 years incident glaucoma and/or OHT (i) and DR (ii). RESULTS: Persons with diabetes were more likely to develop glaucoma and/or OHT (multivariable adjusted HR 1.11, 95% CI 1.06-1.15), but this did not depend on the level of DR. In persons with diabetes, those with glaucoma and/or OHT were more likely to develop DR (multivariable adjusted HR 1.12, 95% CI 1.03-1.23) within 5 years. CONCLUSION: In a national cohort, diabetes associated with a little higher risk of upcoming glaucoma and/or OHT, and, inversely, the presence of the latter predicted a higher risk of incident DR. Nevertheless, our data do not seem to justify including glaucoma evaluation in the national Danish DR-screening programme.

Predictors for the outcome of small-incision lenticule extraction for Myopia.

PURPOSE: To study the influence of patient- and surgery-related parameters on the predictability, efficacy, and safety of small-incision lenticule extraction (SMILE) for treatment of myopia. METHODS: This prospective, clinical quality, control study comprised 670 eyes from 335 patients with myopia up to -10.00 diopters (D) (spherical equivalent refraction) and astigmatism up to 2.00 D treated with SMILE in both eyes and followed for 3 months. RESULTS: Preoperative mean spherical equivalent refraction was -7.19±1.30 D. In eyes with emmetropia as the target refraction, 84% obtained uncorrected distance visual acuity ≤ 0.10 logMAR (20/25 or better Snellen equivalent) at 3 months. Mean corrected distance visual acuity (CDVA) improved from -0.03 to -0.05 logMAR (P<.01). Two or more lines of CDVA were lost in 2.4% (16 eyes). The achieved refraction was 0.25±0.44 D less than attempted after 3 months, and 80% (537 eyes) and 94% (631 eyes) were within ±0.50 and ±1.00 D of attempted correction, respectively. Multiple linear regression analyses revealed that spherical equivalent refraction undercorrection was predicted by increasing patient age (0.10 D per decade; P<.01) and steeper corneal curvature (0.04 D per D; P<.01). Safety and efficacy of the procedure were minimally affected by age, gender, and simultaneous cylinder correction. CONCLUSIONS: Undercorrection of 0.25 D and small effects of patient age and corneal curvature suggest that the standard nomogram for SMILE need only minor adjustments. This study suggests that safety and efficacy are not influenced to any clinically significant degree by easily discernible patient factors.

Functional and structural efficacy of a novel combinational therapy of aflibercept and timely focal/grid photocoagulation in diabetic macular oedema: do clinical study results compare favourably with a standard-of-care treated real-world population?

PURPOSE: To evaluate treatment efficacy in diabetic macular oedema (DME) comparing a study population receiving combined intravitreal vascular endothelial growth factor (VEGF) inhibition and focal/grid photocoagulation with a matched, real-world population receiving standard of care treatment. METHODS: In an exploratory study, we included 43 eyes from 32 patients from a previously published study as well as 46 eyes from 38 standard-of-care patients. The study population had received a loading dose of three monthly aflibercept injections followed by focal/grid photocoagulation and additional aflibercept pro re nata. Principal measurements at 12 months were numbers of intravitreal injections, best corrected visual acuity (BCVA) and central retinal thickness (CRT). RESULTS: At baseline, there were no differences between groups regarding age, sex, body mass index, haemoglobin A1 C, systolic pressure or type of diabetes, but the study population had a higher diastolic pressure (81.6 versus 72.1 mmHg, p = 0.03) and a lower duration of diabetes (12.3 versus 23.2 years, p = 0.03). At month 12, patients in the study group had a higher visual acuity (79.6 versus 74.3 ETDRS letters, p = 0.03), despite having received fewer aflibercept injections (4.4 versus 5.9, p < 0.01) with a higher likelihood of having only received the three mandatory injections in the loading phase (39.5% versus 13.0%, p = 0.01). CONCLUSION: In comparison to a matched, real-world DME-population, patients in combined treatment with intravitreal aflibercept and postloading focal/grid photocoagulation obtained a better functional outcome despite having received fewer intravitreal injections. Future randomized studies are needed to evaluate the long-term efficacy of this combined treatment regimen.

Pretraining of basic skills on a virtual reality vitreoretinal simulator: A waste of time.

PURPOSE: To investigate whether pretraining of basic skills in virtual vitreoretinal surgery affected the performance curve when proceeding to procedure-specific modules. METHODS: This study was a prospective, randomized, controlled, two-centre study. Medical students were randomized into two groups: Group 1 pretrained basic psycho-motor skills (Navigation Training level 2 and Bimanual Training level 3) until they reached their performance curve plateau. Hereafter, both groups trained on the procedure-specific modules (Posterior Hyaloid level 3 and ILM Peeling level 3) until they reached their performance curve plateau. Plateau was defined as three consecutive sessions with the same score with an acceptable variation. The primary outcome was time used to reach performance curve plateau in the procedure-specific modules. RESULTS: A total of 68 medical students were included, and equally randomized into two groups. The participants in Group 1 used a median time of 88 minutes to reach plateau in the basic skills modules but did not differ from Group 2 in time to reach plateau on the procedure-specific modules (183 min versus 210 min, p = 0.40) or in the amplitude of plateau. Group 1 and 2 differed significantly in the starting score of ILM peeling level 3 (0 (0-0) versus 3.5 (0-75), p = 0.03). CONCLUSION: We were not able to show positive skill transfer from basic skills training to the procedure-specific modules in time, starting score or amplitude of plateau. Thus, we recommend that aspiring vitreoretinal surgeons proceed directly to simulation-based training of procedures instead of spending valuable training time on basic skills training.

[Pathological and therapeutic possibilities in inhibiting ocular angionesis].

In a variety of corneal and retinal diseases, ocular ischaemia mediates vascular endothelial growth factor (VEGF) expression, which in turn causes angiogenesis and increased vascular permeability. Consequently, VEGF-inhibitory treatment has been introduced in different ocular diseases. Hypoxia-inducible factor (HIF)-1α is an upstream regulator of VEGF-A, and increased HIF-1α expression has been established in ocular animal models. Upcoming translational studies are expected to increase our understanding of the complex balance between pro- and anti-angiogenic factors in the eye.

[Simulation-based training in ophthalmologic surgery].

Over the past few decades, simulation-based training has become an increasingly widespread learning tool for training in medical procedures. This type of training provides the opportunity to learn in a safe simulation-based environment, where both technical and diagnostic skills can be developed. In Denmark, there has been developed evidence for simulation-based training in ophthalmology in cataract and vitreoretinal surgery. This form of evidence-based training is meaningful for real clinical setting, and in this review, we argue, that is important to apply for all medical fields.

Virtual vitreoretinal surgery: effect of distracting factors on surgical performance in medical students.

PURPOSE: We aimed to investigate the effect of four distracting factors on surgical performance in virtual vitreoretinal surgery. METHODS: Nineteen novice surgeons completed a validated training programme on the Eyesi surgical simulator (VRmagic GmbH, Manheim, Germany; software version 2.9.2) until a calculated target score was reached. The training programme consisted of four modules: navigation level 2 (Nav2), bimanual training level 3 (BimT3), posterior hyaloid level 3 (PostH3) and internal limiting membrane peeling level 3 (ILMP3). When properly trained, the participants completed the training programme once without distraction to generate reference scores and times. Next, they conducted the training programme under the influence of each of the following: auditory distraction, 12 hr of fasting, interrupted sleep and 24 hr of sleep deprivation. Wilcoxon signed-rank test was used to compare the distraction-induced results to the participants' reference scores and times. RESULTS: As compared to reference score (328), a lower performance was found for all four distractions: auditory distraction (289, p = 0.0012), fasting (302, p = 0.02), sleep interruption (304, p = 0.02) and sleep deprivation (300, p = 0.0006). In particular, PostH3 performance was influenced by all four interventions. (86 versus 50, p = 0,0012, 65, p = 0.05, 72, p = 0.05, 54, p = 0.0007 respectively). CONCLUSIONS: Virtual vitreoretinal surgery is an important tool for practicing complex surgical skills without compromising patient safety. In this study, deleterious effects on surgical performance were induced by four independent distracting factors. This knowledge is useful to optimize surgeons' work conditions and ensuring the best possible treatment of patients.

Comparison of corneal biomechanical changes after refractive surgery by noncontact tonometry: small-incision lenticule extraction versus flap-based refractive surgery - a systematic review.

Corneal refractive surgery disrupts corneal integrity and reduces biomechanical stability in consequence of the beneficial refractive alteration. The minimal invasive cap-based refractive procedure, small-incision lenticule extraction (SMILE), has been proposed to affect corneal integrity less than flap-based procedures, due to the fibre-sparing incision of the strong anterior corneal lamellae. Flap-based procedures include laser-assisted in situ keratomileusis (LASIK), femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and femtosecond lenticule extraction (FLEx). The purpose of this systematic review was to evaluate corneal biomechanical changes by noncontact air pulse tonometry after treatment of myopia/myopic astigmatism with SMILE compared to flap-based refractive surgery. A total of 220 publications were identified through a systematic search in PubMed and Embase. Two levels of screening identified nine studies (three randomised controlled trials (RCT) and six nonrandomised clinical trials) eligible for the review. All the nonrandomised clinical trials were graded to have an overall serious risk of bias. Measurements with the Corvis ST were not included in any of the eligible studies. The RCTs found no statistical significant differences between SMILE or flap-based procedures concerning corneal hysteresis (CH) or corneal resistance factor (CRF), as measured with the Ocular Response Analyzer. However, a greater reduction in CRF and CH was found in the flap-based group in five and two of the nonrandomised studies, respectively. The findings in this review illustrate that the presumed biomechanical advantages of a cap-based small incision could not be demonstrated in existing studies and by commercially available technology. However, studies with lower levels of evidence suggest less affection of corneal viscoelastic properties after SMILE when evaluating corneal stability by noncontact tonometry.