bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composition of phacoemulsificated human lenses analyzed by infrared spectroscopy
Authors: Chaniecki P. , Miszczyk J. , Rekas M. , Paluszkiewicz C. 
Published: September 2016

PurposePhacoemulsification is one of the most popular techniques of treating cataract. During the surgery the vibrating phaco‐probe emulsifies the lens into pieces that are vacuumed into a cassette. Afterwards the shredded lens material is usually disposed. Currently spectroscopic methods are ordinarily applied for studying biological materials due to their high sensitivity, reliability and non‐destructive character. The study attempts to determine whether the infrared spectroscopy technique is appropriate to reveal the differences in the structure of the lenses, especially focusing on the content of substances indicating changes in the secondary protein structure or mineralization process.MethodsIn the study 99 randomly selected dispersed human lenses were analyzed. The procedures of phacoemulsification were performed at the Military Hospital in Cracow and Military Institute in Warsaw. Obtained shredded lenses were forwarded to the Institute of Nuclear Physics at Polish Academy of Sciences in Cracow for further investigation. After appropriate preparation, the material was analyzed by FTIR spectroscopy using Nicolet spectrometer equipped with DTGS detector and ATR attachment. For the accurate interpretation of the spectra of lenses, exemplary samples of albumin, DNA, glucose and hydroxyapatite were also analyzed.ResultsThe FTIR spectra of lenses are characteristic for natural tissues and are dominated by intense bandwidth derived from amides and lipids. The FTIR spectra of the lenses are most similar to the spectrum of albumin.ConclusionsThe material obtained during phacoemulsification is suitable for infrared spectroscopic investigation. The FTIR method allows for the determination of human eye lenses structure and enables to indicate the differences in their composition.
Static retinal vessel analysis in routine optometric practice
Authors: French C. , Heitmar R. 
Published: September 2016

PurposeTo evaluate the use of objective retinal vessel calibre measurements in optometric practice and its utility in clinical decision making.MethodsA sub‐sample [n = 56] was extracted from a prospective study including patients booked for routine eye examinations in optometric practice. All participants underwent a standard examination including subjective refraction and slit lamp biomicroscopy. Undilated fundus photography and/or optical coherence tomography (OCT) was also performed. Optic nerve‐centred (camera angle: 50 degrees), red‐free photographs were analysed using VesselMap software (Imedos, Germany) to give objective vessel calibre measurements (central retinal artery and vein equivalents (CRAE / CRVE)).ResultsMean age of the cohort was 56 years (range: 21–82 years; consisting of 32 women and 24 men). Univariate analysis showed a significant association between systolic blood pressure and CRAE which was lost in multivariate analysis (p = 0.02). Stepwise forward multiple regression analysis found age to be significantly, negatively associated with CRAE (CRAE: 157au (SD ± 20); β = −0.54; p < 0.001) and CRVE (β = −0.56; p < 0.001), whereas BMI was positively associated with CRVE (198au (SD ± 20) au; β = 1.84; p = 0.005) only. Two patients were measured twice: on initial presentation, one with a significant retinal haemorrhage and one with unilateral papilloedema; both showed normalisation of vessel diameters on follow up.ConclusionsParticipants with the largest CRVE had the highest BMI and/or were diabetic. Cross‐sectional results from this sample are in agreement with results published from large cohort studies, including the negative association with age and CRAE. Retinal vessel calibres can help provide information on a patient's vascular system and systemic health, and therefore be a useful tool to refine optometric referrals and aid patient monitoring.
Trends in glaucoma surgical procedures in Portugal – a national database report 2000–2014
Authors: Barbosa Breda J. , Gonçalves‐Pinho M. , Vasco Santos J. , Rocha Sousa A. , Freitas A. 
Published: September 2016

PurposeTo analyze trends in the surgical management of glaucoma, in Portugal, from 2000 to 2014.MethodsWe performed a retrospective analysis of all episodes for inpatients or surgery outpatients in all public nationwide hospitals, with a diagnosis of glaucoma/ocular hypertension (coded 365.xx) or trabeculectomy ab externo (code 12.64) or insertion of glaucoma drainage device (GDD, code 12.67) or other scleral fistulizing procedure (code 12.69, used for GDDs prior to 2011), and analyzed associated eye procedures (ICD 9‐CM codes 08.xx to 16.xx).ResultsIn 15 years, the total number of eye procedures was 55,081 (17.6% of all coded procedures), with an increase in the number of eye procedures from 2,614 in 2000 to 5,400 in 2014 (34.1 and 11.3% of all coded procedures, respectively). Overall, trabeculectomy ab externo was the second most performed eye procedure (20.6%), second only to cataract extraction with phacoemulsification. Although the absolute number per year has an almost steady profile (747 in 2000, 643 in 2014), the relative frequency of this procedure has decreased from 28.6% in 2000 to 11.9% in 2014. On other hand, GDDs had an increase both in absolute and relative values [(17 (0.7%) in 2000, steady until 2008 – 21 procedures (0.5%), and then increasing until 2014 – 327 procedures (6.1%)]. As for cyclodestruction (cryotherapy or photocoagulation), there is an increase in the total number of procedures (75 in 2000, 217 in 2014), but their relative frequency is stable throughout the study period (2.9% in 2000, 4.0% in 2014).ConclusionsTrabeculectomy ab externo remains the most widely performed IOP‐lowering surgical procedure. However, there is a trend showing a reduction in the frequency of trabeculectomies, whereas there is an increase in GDD use. Cyclodestruction has a stable frequency in the number of procedures throughout the study period.
Deep learning approach for diabetic retinopathy screening
Authors: Colas E. , Besse A. , Orgogozo A. , Schmauch B. , Meric N. , Besse E. 
Published: September 2016

PurposeDiabetic retinopathy (DR) is the major cause of blindness in the working‐age population. With an increasing number of diabetic patients worldwide, automated screening tools become indispensable. Recent progress in machine learning and image analysis enables efficient automated screening.MethodsDreamUp Vision uses state‐of the art technology based on deep‐learning. Our algorithm was trained on over 70,000 labeled retinal images. Images were graded by ophthalmologists as follows: 0 (no retinopathy), 1 (mild non proliferative DR), 2 (moderate non proliferative DR), 3 (severe non proliferative DR) and 4 (proliferative retinopathy). Each patient in the dataset is represented by two images of left and right eyes. Grading is done for each eye image separately. Our algorithm performs quick and reliable detection of anomalies in retinal images, diagnoses their stage of diabetic retinopathy and provides the location of the anomalies detected in the pictures. We consider a patient as referable if the DR stage is between 2 and 4, otherwise we consider the patient as non‐referable. We evaluate our model on over 10,000 fundus images from 5,000 patients taken from the Kaggle DR Detection Challenge dataset, provided by California Healthcare Foundation.ResultsOur algorithm achieves an area under the receiver operating characteristic curve AUROC of 0.946 with 96.2% sensitivity (95% CI: 95.8–96.5) and 66.6% specificity (95% CI: 65.7–67.5) for identifying referable DR on the Kaggle dataset.ConclusionsThe performances we have obtained enable a reliable automated DR screening. As the amount of available labeled data grows and given our technology's ability to learn from labeled images, we believe that significant performance improvement can be achieved. The same process can be applied to the detection of other eye diseases as well.
Visualizing retinal vessel dynamics of young type 1 diabetic patients using self‐organizing map
Authors: Haikonen S. , Kytö J. , Kämäräinen J.K. , Kauppi J.P. , Huttunen H. , Groop P.H. , Summanen P. 
Published: September 2016

PurposeTo reveal possible differences in retinal arterial dynamics between patients with type 1 diabetes (T1D) and healthy subjects using data‐driven analysis.MethodsThe retinal arterial diameter was measured as a function of time in one eye of 94 T1D‐patients (mean age 32 years, range 22–54) and 29 healthy subjects (mean age 33 years, range 24–50) during stable light conditions and flickering light stimulus using Dynamic Retinal Vessel Analyzer (DVA; Imedos GmbH, Jena, Germany). Diabetic retinopathy (DR) of T1D patients was graded using ETDRS classification: 41 without DR, 50 only mild DR and 3 moderate or more severe DR. The raw DVA data was preprocessed and subsequently analyzed with Self‐Organizing Map (SOM). SOM is a data‐driven method which was here used to cluster DVA time courses of the subjects and to visualize the data in a map‐like image.ResultsThere were differences in retinal arterial response patterns between healthy subjects and T1D patients. The response patterns of the T1D patients seemed milder than those of the healthy subjects. The severity of DR was associated with flatter shape of the response curve. SOM also revealed distinct subgroups among T1D patients.ConclusionsWeaker vascular responses observed in T1D patients as compared to healthy subjects were in line with earlier studies. However, in this series, the interest was to study mostly T1D patients with no or only mild retinopathy, making the detection of differences in artery dynamics challenging. The response patterns of the T1D patients fell into distinct clusters, indicating that there may be other factors explaining the shape of the curves than T1D.
Heads‐up eye surgery: pros and cons
Authors: Lytvynchuk L. 
Published: September 2016

PurposeTo evaluate the use of Heads‐up approach for eye microsurgical procedures.MethodsThe Heads‐up system TrueVision 3D Surgical (Santa Barbara, CA, USA) combined with operating microscope Lumera 700 (Carl Zeiss Meditech, Oberkochen, Germany) was used during the surgeries on anterior and posterior segment of the eye by two experienced surgeons. The time that was necessary for getting used to the heads‐up surgery was assessed. The magnification and the colours on the screen were compared with those seen through the ocular of the microscope. The surgeon's posture using standard oculars and heads‐up system was assessed and compared as well.ResultsThe first surgery performed by each surgeon was fully done with he use of heads‐up system. The duration of the first 2 surgeries was approximately 15–20 min longer comparing to the standard approach. The duration of every next surgery was shorter and finally on the 5th surgery didn't differ from the one done with standard approach. The colours on the 3D display were different from those seen through the oculars, but it was possible to do the digital adjustment of the colours. The magnification of the ocular structures with 3D system was bigger comparing to the magnification in standard oculars. The posture of the surgeon was more flexible during the surgeries with 3D system.ConclusionsNew 3D technology allows the surgeon to work with the bigger magnification and in more relaxed position. The colours of the ocular tissues with 3D system differ from the colours seen through the standard oculars, but can be adjusted by the special software. Heads‐up surgery necessitates a learning curve, which is relatively short.
Congenital aniridia: an epidemiological approach on 105 patients
Authors: Salviat F. , Robert M. , Michel S. , Bremond‐Gignac D. 
Published: September 2016

PurposeAniridia is a rare ocular disorder affecting beside iris, cornea, angle structures, lens and fovea, and possibly associated with other anomalies. This study aims at understanding features of patients with congenital aniridia, identifying the characteristics phenotypes of the disease and its associated anomalies.MethodsPatients affected by congenital aniridia were prospectively included and clinically examined at two french pediatric reference centers, with local ethics committee approval. Following parameters were assessed: sex ratio, sporadic or familial history, associated eye anomalies (glaucoma, limbal deficiency, cataract).ResultsThe study included 105 patients of the 135 registered at Ophtara Rare Disease Center with CEMARA data basis. The median age at last examination were 10 years old (3 days; 75 years) with a 65% rate and a mild female predominance (sex ratio 0.65). All patients had bilateral aniridia, with a remaining iris insertion uni or bilateral in 32 patients (30.5%). Thirty patients had a familial form of aniridia (28.6%). Aniridia was isolated in 94 p. (89.5%), and associated with 7 WAGR syndromes, one WAGRO syndrome, one Gillespie syndrome. Cataract was described in 51 patients (49%) – bi (41%) or unilateral (8%) –, limbal deficiency in 59 p. (56.2%), and glaucoma in 45 p. (42.9%). A mutation of the PAX6 gene was registered in 23 p. (21.9%), with no obvious genotype‐phenotype correlation. In absence of iris insertion, the relative risk of glaucoma was assessed at 1.6 (IC 95% [1.03; 2.58]).ConclusionsThe aniridia phenotype characteristics varies widely. Risk factors for glaucoma/limbal insufficiency have to be better defined by further studies and a standardization of the flow charts clinical elements to collect should provide better insight in further congenital aniridia data collection.
The role of LRG1 in vessel normalization
Authors: Sepetis A. , O'Connor M. , Dowsett L. , Hoeh A. , Gourlaouen M. , Moss S. , Greenwood J. 
Published: September 2016

PurposeIn diseases characterized by abnormal neovascularization, the new vessels lack adequate pericyte (PC) coverage. TGFβ is involved in the recruitment of PC through ALK1‐Smad1/5/8 and ALK5‐Smad2/3 signalling. The first signalling pathway inhibits differentiation into mural cells while the latter promotes it. Leucine‐rich α‐2‐glycoprotein 1 (LRG1) is a modulator of TGFβ signalling. By binding to endoglin, LRG1 promotes the ALK1‐Smad1/5/8 signalling pathway. We hypothesized that LRG1 may have an important role in PC recruitment.MethodsRetinae from Lrg1−/− and WT mice were trypsin‐digested and the endothelial cell (EC)/PC was calculated. The oxygen‐induced retinopathy mouse model was used to assess PC coverage in the neovascular tufts and the leading edge of the revascularization in Lrg1−/− and WT mice. The retinae were stained for the PC markers NG2 and αSMA and the EC marker CD31. NG2/CD31 and αSMA/CD31 ratios were quantified in the above areas. Moreover, metatarsals from mice fetuses were treated with PBS, LRG1 and angiogenic factors either alone or in combination. Then they were stained for NG2 and CD31 and the fraction of CD31 overlapping with NG2 was quantified.ResultsQuantification of EC/PC ratio revealed no difference between the control genotypes. In the neovascular tufts, Lrg1 deletion leads to a higher ratio of NG2+ PC whilst at the leading edge of the revascularization of the avascular region, PC coverage was not affected. In the metatarsals the combination of VEGF + LRG1 leads to significantly lower PC coverage compared to the control.ConclusionsWe demonstrate that under physiological conditions, deficiency of Lrg1 does not alter perivascular coverage. However, during abnormal neovascularization, Lrg1 deficiency seems to lead to increased PC recruitment while exogenous supplementation of LRG1 especially in combination with VEGF decreases it.
Correlation between retinal and mixed venous oxygen saturation
Authors: Van Keer K. , Abegão Pinto L. , Stalmans I. , Vandewalle E. 
Published: September 2016

PurposeTo investigate the correlation between mixed venous (SvO2) and retinal vessel (SrO2) oxygen saturation, using non‐invasive spectroscopy in pre‐ and post‐ heart transplant patients.MethodsRetinal oxygen saturation and vessel caliber were measured in dark‐adapted patients, breathing ambient air in a seated position, using dual wavelength retinal oximetry, within 24 h of a SvO2 sampling during right heart catheterization. Correlations were analyzed using Pearson correlation coefficients and linear regression models.ResultsTwelve patients aged 57.4 ± 18.2 years were analyzed. A strong negative correlation was found between retinal arteriovenous oxygen difference and SvO2 (r = −0.64, p = 0.024), as well as between retinal arterial diameter and time since heart transplantation (r = −0.77, p = 0.009), independent of demographic and systemic parameters.ConclusionsRetinal oximetry provides a non‐invasive method to visualize and quantify the oxygen saturation of arteries and veins of the central circulatory system. This pilot study provides proof of concept for the use of retinal oximetry in the follow‐up of patients after heart transplantation, to assess cardiac function as well as cardiovascular health.
Vitreous and subretinal VEGF levels in fresh rhegmatogenous retinal detachment
Authors: Sozen‐Delil F.I. , Cekic O. 
Published: September 2016

PurposeTo explore the levels of vascular endothelial growth factor (VEGF) in vitreous and subretinal fluid in eyes with rhegmatogenous retinal detachment.MethodsOverall 16 eyes of 16 patients (mean age, 49) with fresh rhegmatogenous retinal detachment were included into this study. There was no systemic or ocular disease other than the retinal detachment that might contribute to results in the patients. Vitreous samples (n = 9) were obtained during pars plana vitrectomy whereas subretinal fluid samples (n = 7) were obtained via external drainage during encircling sclera buckle surgery. Serum and vitreous VEGF levels were analyzed using enzyme‐linked immunosorbent assay. Total vitreous or subretinal fluid proteins and total serum proteins were also measured. Mann–Whitney U and Spearman correlation tests were performed to compare the VEGF concentrations.ResultsMedian VEGF level was found higher in subretinal fluid when compared to vitreous (545.80 pg/ml vs. 106.08 pg/ml, p = 0.05). The difference was still significant after adjusting the results with total protein (p = 0.05). Subretinal fluid VEGF level was similar to serum VEGF level (410.30 pg/ml) in buckling group (p = 0.95) while serum VEGF level (221.20 pg/ml) was significantly higher than that of vitreous in vitrectomy group (p = 0.019). There was no correlation between serum and subretinal VEGF (p > 0.05) or serum and vitreous VEGF levels (p > 0.05).ConclusionsThe retinal pigment epithelium is the major source of VEGF in the eye. The current study confirmed that VEGF level in subretinal fluid is higher than that of in the vitreous in eyes with fresh retinal detachment, most probably due to the retinal pigment epithelium is in closer vicinity to the subretinal fluid, compared to vitreous humor.AcknowledgementThis project was supported by Marmara University, Scientific Research Projects Committee.
Visualization of neovascular changes by swept source OCT angiography
Authors: Szaflik J.P. , Szaflik M. 
Published: September 2016

PurposeInstruments for using OCT angiography have recently become available. The aim of this paper is to report the possibilities, advantages and disadvantages of OCT angiography in the clinical diagnosis of retinal and choroidal neovascular diseases.MethodsThe OCT angiography images were obtained in patients with retinal neovascular diseases such as AMD and diabetic neovascular retinopathy and in patients with doubtful macular changes. OCT angiography was also performed as a follow up after intravitreal injections.ResultsOCT angiography images might be helpful in proper diagnostic process of neovascular changes. The examination is quick, harmless and performed without intravenous contrast. The quality of OCT angiography images depends on patients compliance and translucency of eye optical system. The movement artefacts are the most common.ConclusionsOCT angiography is a new diagnostic tool which might be useful in visualization of pathological vessels and solving diagnostic problems of doubtful changes. It's worth to perform OCT angiography before traditional angiography. It would also be useful in patients with intolerance to fluorescein or indocyanine.
Collagen biomaterials for cornea regeneration – how does it work
Authors: Griffith M. , Reddy J. , Liszka A. , Lewis P.N. , Hayes S. , Meek K.M. 
Published: September 2016

SummaryWe have previously shown in animal models and in early clinical studies that collagen‐based biomaterials promoted functional regeneration of corneal epithelium, stroma and nerves. Recently, we showed that these fabricated implants were made of collagen fibrils that were fine and aligned, like those in human corneas. There were noticeable differences such as the uniaxial alignment of the implant fibrils compared to the biaxial alignment in the cornea, and the lack of D‐banding of collagen fibrils in the implants. Nevertheless, the aligned fibrils facilitated an orderly in‐growth of corneal stromal cells to form a neo‐stroma. TEM examination showed the presence of extracellular vesicles (EVs) in the regenerating corneas. Immunohistochemistry showed that the EVs were positively stained for collagen amongst other cargoes. In implants made from short peptide analogs of collagen, alignment of short fibrils was observed. However these implants had a much higher number of EVs. This suggests that a combination of a scaffold comprising highly aligned fibrils mimicking the highly ordered corneal ECM together with elaboration of collagen and other ECM macromolecules is required for regeneration of a functional neo‐cornea and not scar tissue.
Weill‐Marchesani syndrome: displaced lens, displaced pupil, displaced diagnosis
Authors: Hussain N. , Jeyabaladevan S. , Macapagal M. , Tumbocon J. 
Published: September 2016

PurposeWeill‐Marchesani Syndrome (WMS) is a rare, multi‐system, connective tissue disorder characterised by short stature, brachydactyly and ocular disturbance in late childhood. The cardinal ophthalmic feature is a microspherophakic lens which commonly results in lens subluxation, lenticular myopia, cataract formation and chronic glaucoma. Corectopia is a finding associated with lens subluxation but can also be a complication of ocular surgery. Until now, there are no reported cases of corectopia in WMS.MethodsWe describe the case of a 26‐year‐old female who presented with progressive blurring of vision on a background of high myopia, glaucoma and bilateral cataracts. The patient had undergone multiple procedures to control intraocular pressures, including bilateral trabeculectomy and glaucoma valve insertion in the left eye. She was diagnosed with WMS two years ago, but was lost to follow up.ResultsExamination revealed inferior subluxation and opacification of the lens bilaterally. Interestingly, the left pupil was displaced nasally and corneal bullae were noted on the inferior surface of the left eye. She was listed for bilateral phacoemulsification and intraocular lens insertion following this consultation, however re‐presented with sudden deterioration in vision within one week. Her right lens was displaced anteriorly but there was no corneal oedema. She subsequently underwent emergency lensectomy and was left aphakic in that eye.ConclusionsWMS often goes undiagnosed in childhood. A greater awareness of the presenting features of the condition is important for early recognition and referral onto secondary care for specialist ophthalmic input. Our experience demonstrates that screening for complications is of paramount importance and early lensectomy may prevent irreversible ocular damage and improve visual outcomes.