bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of corneal epithelial cells with confocal microscopy after lamellar keratoplasty
Authors: GAUJOUX T , TOUZEAU O , KOPITO R , LAROCHE L , BORDERIE VM 
Published: November 2009

Abstract Purpose the purpose of this study was to analyze morphometry of corneal epithelial cells in normal eyes and after anterior lamellar keratoplasty using confocal microscopy. Methods The combination of the Heidelberg Retina Tomograph II and the Rostock Cornea Module (HRT II/RCM) was used to evaluate the corneal epithelium of 10 eyes of patients who had undergone anterior lamellar keratoplasty (ALK group) and 10 normal eyes (control group). Three epithelial layers per cornea were examined: superficial cell layer, wing cell layer, and basal cell layer. A morphometric analysis software was used to determine area, perimeter, circularity, and Feret diameter of the corneal epithelial cells. Results The mean basal cell area in the central zone was significantly higher (p< 0.001) after ALK than in the control group. After ALK, the mean basal cell area decreased with post‐operative time (rS = ‐ 0.42; p = 0.039) but it did not return to normal 24 months after transplantation. Comparison of both groups showed significant differences in cell perimeter, circularity, and Feret diameter of basal cells (p< 0.001). Similar differences were found in wing cell layer. Only few superficial cells could be analyzed on corneal graft (no statistical analysis could be done). Conclusion This study imaged the living human basal epithelium of lamellar grafts, analyzed its structure and highlighted changes in epithelial cells density and morphology. We found an increase in basal cell density between 12 and 30 months. This could be explained by reinnervation of the cornea. Indeed, corneal nerves provide important protective and trophic functions. The basal cell area seems to be a relevant morphometric parameter to assess the corneal epithelium.
Infectious crystalline keratopathy and its management
Authors: DUA HS , SAID DG 
Published: November 2009

Abstract Purpose Infectious crystalline keratopathy (ICK) is defined as microbial infection of the cornea in the absence of the host inflammatory response. It presents as slowly progressive crystalline opacities resembling needles, snowflakes or ferns and are filamentous or branching in pattern within the cornea stroma. Methods Pathogenesis: Streptococcus viridans is the most common cause of ICK but a range of fungi and bacteria have been isolated from cases of ICK. They are located within the corneal stroma within the interlamellar planes. The pattern of spread of bacteria within corneal tissue is determined by the compactness of the corneal stroma. Another common feature is reduced corneal sensation, abrogating the triple response reflex at the limbus and hence the lack of the host response. The diagnosis of ICK is made on history and examination as microbiological diagnosis by culture of scrapes is difficult. Histology of biopsy specimen confirms diagnosis. Results Medical treatment with broad spectrum topical anti‐microbial agents is initiated. Any concomitant use of topical steroids should be discontinued. If no resolution of infection occurs, surgery in the form of lamellar or penetrating keratoplasty or superficial keratectomy is required. The successful use of excimer laser therapeutic keratectomy and Nd:YAG laser in the treatment of ICK has been demonstrated in single case reports but these techniques need further evaluation. Conclusion The diagnosis of ICK is largely clinical. It is difficult to treat medically often requiring surgical intervention. Poor corenal sensation and steroid use are important predisposing factors.
Assessment of macular pigment optical density (MPOD) among patients with wet age‐related macular degenaration (AMD) in one eye and the dry form in the fellow eye
Authors: TSIKA CI , KONTADAKIS GA , MAKRIDAKI M , PLAINIS S , MOSCHANDREAS J , TSILIMBARIS MK 
Published: November 2009

Abstract Purpose To estimate the Macular Pigment Optical Density (MPOD) in patients with unilateral wet Age‐Related Macular Degenaration (AMD), not taking any carotenoid supplements. Methods The MPOD was measured in 20 patients (73.7±5.32 years) and in 20 healthy‐retina subjects (71.6± 5.19 years) using Heterochromatic Flicker Photometry. Independent‐samples t test was performed between patients’ eye with dry AMD and controls’ right eye. Results No significant difference (mean difference: 0.01 (p=0.845)) was observed between the Macular Pigment Optical Density (MPOD) of the fellow dry AMD eye of patients with unilateral wet AMD (mean MPOD: 0.51 ± 0.16) and the eyes of age‐matched control subjects (mean MPOD: 0.52 ± 0.15). Conclusion Patients with unilateral wet AMD were not found to have less Macular Pigment than healthy subjects of same age. This finding suggests that MPOD might not be useful as prognostic factor for the progression of the disease at this high‐risked group of patients.
Perioperative bevacizumab injection: clinical and histological results
Authors: ROMANO MR , GIBRAN SK , WONG D , HISCOTT P , HEIMANN H 
Published: November 2009

Abstract Purpose To evaluate the safety and efficacy of Intravitreal Bevacizumab (IVB) injection as an adjuvant in the management of proliferative diabetic retinopathy (PDR) before or after planned vitrectomy. Methods Prospective, interventional, consecutive case series of 58 eyes of 55 patients with PDR. The patients were divided in two groups: Group A (28 eyes) had IVB within 10 days before the surgery; Group B (30 eyes) had the IVB at the end of the surgery. A dose of IVB was of 2.5mg in 0.1 ml and was given under aseptic conditions. The specimens obtained from the both groups were evaluated by histological examination. Results In Group A, 3 of 28 eyes (12%) had no significant reduction of neovascularisation; 8 of 28 eyes (28%) had a significant reduction in leakage and regression of tractional retinal detachment (TRD) with parallel improvement in visual acuity. Four (50%) of these 8 patients had recurrence of PDR within 10 weeks after the injection. In 2 patients, worsening of TRD was noted. In 11 patients, vitrectomy, delamination and endolaser laser were performed within 10 days. Post‐operative bleeding was not noted in this group. In Group B, 7 out of 30 eyes (23%) had a re‐bleeding within one month from the surgery. No difference in morphology was observed between the specimens of the two groups. An analogous staining pattern was observed between two groups when comparing markers for apoptosis (caspase), hypoxia (HIF1 and HIF2) and VEGF. Conclusion IVB seems to be efficacious as an adjuvant treatment, if injected pre‐operatively rather than post‐operatively, for the management of PDR. IVB does not appear to cause any change in the light microscopic appearance or in the immunohistochemically‐detectable expression of hypoxia or apoptosis markers.
The ophthalmological approach
Authors: SPILEERS W 
Published: November 2009

Abstract Purpose Patients with unvoluntary eye movements frequently consult an ophthalmologist. A correct diagnosis of the type and etiology is important. Methods A clinical approach with selected technical examinations is mandatory for a correct diagnostic approach. Results Isolated ophthalmological and combined neurological elements can be identified to guide the further approach. Conclusion A practical work‐up of a patient presenting with nystagmus will be presented. Frequently the collaboration with the neurologist is important.
First results in repeated functional testing in low vision patients with retinitis pigmentosa
Authors: GEORGI T , IVASTINOVIC D , HORNIG R , KOCH M , VELIKAY‐PAREL M 
Published: November 2009

Abstract Purpose We created a visual function test, the Graz mobility (GM) test to document visual progress in artificial vision. In previous studies our low vision test adequately graded the low vision of patients with retinitis pigmentosa (RP). However in repeated testing the learning effect could contaminate the visual results after implantation. The aim of this study was to investigate the constancy of the performance and to record behavioural changes in repeated testing in low vision RP patients. Methods 8 low vision RP‐patients with a visual acuity from hand motion to 20/800 were tested repeatedly in 1, 2, 3 and 6 months time intervals. The GM test consisted of four different, structurally similar mazes with 11 obstacles. The subjects passed through each course several times. A people tracking system with an integrated trajectory projection system was established to record horizontal and vertical scanning movements of people during the test. Passage time, walking speed, number of contacts, frequency of scanning movements and average scanning angle were recorded. Results In repeated testing significant changes of the passage time were observed once the patients became familiar with the mobility test. The maximum learning effect was achieved within the first test session and was never exceeded in the following sessions. However further changes in the remaining parameters were observed in each patient, displaying behavioural changes correlating to the level of comfort during the task performance. Conclusion The GM proves to be reliable for repeated testing in low vision patients and the learning effect will not contaminate the results of visual function changes. Furthermore behavioural changes can be objectively assessed.
Effect of VEGF blockade on corneal graft neovascularization and rejection in rats
Authors: ROCHER N , BEHAR‐COHEN F , RENARD G , BOURGES JL 
Published: November 2009

Abstract Purpose To evaluate the effect of anti‐vascular endothelial growth factor antibodies directed at VEGF 164, 120, 121 and 165, administered by subconjunctival injections (SC), on neovascularization and rejection after penetrating keratoplasty (PK) in rats Methods Twelve Lewis rats were grafted with corneal buttons from Brown Norway rats and were divided in 2 treatment groups (G) just after surgery (day 0). G1 received saline SC injections (0.02ml/inj, n=6) every 3 days from D0 to D21 and G2 received SC injections of anti‐VEGF (0.02ml/inj, 10µg/ml), with the same regimen. Rejection clinical scores were based on corneal oedema (0 to 3) and transparency (0 to 4). Surface and extension of neovascularization were scored clinically (0 to 4) and then quantified using lectin immunostaining on flat‐mounted buttons Results At D21, the mean rejection scores were significantly higher in G1 compared to G2. Rejection rates were 83% in G1 vs. 50% in G2 (p<0.05). Neovessels scores were 4±0 in G1 vs. 2.5±0.54 in G2 (p<0.001). On flat‐mounted corneas the mean ratio of vessels area/clear cornea was 58% in G1 vs. 36% in G2 (p=0,003). Conclusion The sub conjunctival administration of anti‐VEGF antibodies not only reduces neovessels growth but also prevent rejection after PK.
Signaling pathways in innate immunity
Authors: SALMINEN A 
Published: November 2009

AbstractInflammation has a key role in the pathogenesis of AMD. This lecture will review the recent progress in understanding the different host‐defence mechanisms against pathogens and self‐based danger signals involved in the activation of innate immunity. The innate defence system utilizes pattern recognition receptors (PRR) to respond to a variety of pathogen‐associated (PAMP) and danger‐associated (DAMP) molecular structures. Along with the well‐known complement and scavenger receptor systems, Toll‐like receptors (TLR) and NOD‐like receptors (NLR) have also a crucial part in host‐defence and these receptor systems can be activated both by PAMPs and DAMPs. Pattern recognition receptors are located either in cell surface, such as TLR2 and TLR4, or in intracellular locations, e.g. TLR3, TLR9 and all NLRs. PRRs show some specificity to ligands and also in downstream they activate different signaling pathways, most common of which are NF‐kB and IRF‐dependent pathways inducing inflammatory responses. Retinal pigment epithelial cells (RPE) have an important role in eye host‐defence, both at apical and basolateral surfaces. Most of the TLRs are expressed in RPE cells, especially TLR3 and TLR4, and they can participate in photoreceptor outer segment recognition. TLR3 can also suppress angiogenesis. The functions of NLRs, e.g. those forming inflammasomes, are still unknown, although the danger‐type of activation signals, such as oxidative stress and potassium efflux, are present in retinal pigment epithelium. It seems that the activation of innate immunity system via DAMPs and PRRs may have a central role in the pathogenesis of AMD.
Evaluation of contrast sensitivity on monocularly ‐ deprived subjects
Authors: GIANNAKOPOULOU T , PLAINIS S , PALLIKARIS IG , TSILIMBARIS MK 
Published: November 2009

Abstract Purpose It is widely accepted that monocular deprivation results to improved visual performance of the non‐pathological eye. The aim of the study was to investigate the effect of monocular deprivation on the contrast sensitivity performance of the fellow eye. Methods Sixteen subjects (mean age: 28.0 ± 7.9) with monocular deprivation volunteered to participate in the study. Eleven more subjects (mean age: 28.1 ± 3.6) served as the control group. Best‐corrected visual acuity was ‐0.15 ± 0.09 and ‐0.16 ± 0.08 logMAR, correspondingly. Best‐corrected contrast sensitivity was evaluated using vertical sinusoidal gratings (2 Hz square‐wave reversal) displayed on a Sony GDM F‐520 CRT display at 200cm distance, by means of a VSG2/5 stimulus generator card (CRS, Rochester, UK). Seven spatial frequencies (1, 2, 4, 8, 12, 16 and 24 c/deg) were tested. The average of three thresholds was taken. Performance of the control group was tested both monocularly (dominant eye) and binocularly. Results Binocular viewing improves contrast sensitivity by about 3.5 dB in control subjects. Contrast sensitivity was found to be higher (4.6 dB on average) for monocularly‐deprived subjects, compared with the dominant eye of the control group. However, the effect was spatial frequency‐dependent: the difference was more pronounced for low and high spatial frequencies. Conclusion Monocularly‐deprived subjects show higher contrast sensitivity compared to monocular values of normal young subjects. The improved performance of the non‐pathological eye of patients with monocular deprivation may be a result of the neuronal synaptic plasticity of the visual cortex.
Variability of color doppler imaging parameters and consequences for sample size calculations
Authors: VANDEWALLE E , SIESKY B , ZEYEN T , HARRIS A , STALMANS I 
Published: November 2009

Abstract Purpose The aims of this study were: 1) to determine the intra‐observer variability of color Doppler imaging (CDI) measurements, 2) to compare the difference in variability of these measurements in healthy controls versus glaucoma patients, and 3) to provide calculations of minimum sample sizes for future CDI studies. Methods Patients with normal tension glaucoma (n=28), primary open angle glaucoma (n=19) and age‐matched healthy controls (n=22)underwent CDI on two occasions one month apart. Variability in CDI measurements was quantified using (within‐subjects) coefficients of variation. Based on this variability, minimum sample sizes were calculated to guide the design of future studies comparing CDI between and within groups. Results In general, within‐subject coefficients of variation for measurements one month apart were comparable to previously reported short‐term variations. Variability was higher in glaucoma patients than in healthy controls. The minimum sample size required for glaucomatous study populations is larger than for healthy controls. Smaller patient groups are required to detect change using the peak systolic velocities than using end diastolic velocities. Studies using a cross‐over design require smaller sample sizes than studies with a pre‐post or parallel design. Conclusion This study provides extensive information on long‐term intra‐observer variability of CDI measurements in healthy controls as well as glaucoma patients. Moreover, sample size calcualtions are provided for studies involving glaucoma patients as well as healthy individuals using three different study designs.
Selection and assessment of vital dyes to improve the endothelial quality control of organ cultured corneas
Authors: THURET G , DUBAND S , CAMPOLMI N , PIPPARELLI A , PISELLI S , DUMOLLARD JM , PEOC'H M , ACQUART S , GARRAUD O , GAIN P 
Published: November 2009

Abstract Purpose In eye banks, corneal quality control requires an accurate endothelial cell density (ECD). ECs are counted after osmotic preparation (NaCl/sucrose) that makes cells visible. Nevertheless, endothelial images remain often poorly contrasted, non uniform, with a high background noise. Aim: to replace this technique by a non toxic ‘endothelial dye’ Methods 30 dyes were pre‐selected. Ability to stain EC was assessed on porcine, bovine and rabbit corneas. They were exposed (1 min) to pure or diluted dyes and observed under a light microscope using bright field and 4 standard fluorescent filters. Toxicity was assessed in vitro on EC cultures (live/dead assay, Hoechst Ethidium Calcein). Using the same assay, the less toxic dyes were further assessed on keratocytes cultures and on animal corneas organ cultured for 24H after exposure to dyes. Controls: exposure to BSS only or 3% H2O2 Results Only Ledermycin, Hemalun, Rose Bengal, Nuclear Red, Congo red, Evans Blue, and Chicago Sky Blue (CSB) stained ECs, and only the 3 diazoïc dyes (Congo red, Evans Blue, and CSB) stained EC borders using fluorescence (Em554/Ex568nm). Both blue dyes also stained the nuclei of dead cells. Hemalun and Rose Bengal were highly toxic. In vitro and ex vivo toxicity of CSB was negligible. The other dyes had an intermediate toxicity Conclusion Diazoïc dyes and especially CSB could be non toxic dyes for ECs borders. They could improve the accuracy of ECD determination. Their ability to stain human endothelium and their safety (using an animal graft model) have to be assessed as well as their contribution in ECD determination versus the classical osmotic endothelial preparation
25‐hydroxycholesterol increases IL‐8 production in the RPE by activation of PI3K and p38 MAPK pathways
Authors: FERNANDES AF , BRITO A , PEREIRA P 
Published: November 2009

Abstract Purpose Cholesterol oxides have been implicated in the overproduction of proinflammatory cytokines, such as IL‐8. The purpose of this study is to establish whether cholesterol oxides increase IL‐8 production in the RPE and elucidate the molecular mechanism underlying that increase. Methods Cultured RPE (ARPE‐19) cells were incubated with 7‐ketocholesterol (7‐KC) and 25‐hydroxycholesterol (25‐OH). Levels of phosphorylated Akt and p38 MAPK in the cells were determined by Western blotting. Levels of IL‐8 mRNA were assessed by real‐time RT‐PCR. IL‐8 protein levels in the medium were determined by ELISA. Results 25‐OH increases IL‐8 gene expression and secretion in a time‐dependent manner, whereas 7‐KC does not have a significant effect on IL‐8 production. This effect is not suppressed by antioxidants. Inhibition of the PI3K pathway using either chemical inhibitors or dominant negative forms of PI3K prevents the 25‐OH‐induced IL‐8 production. Inhibition of the p38 MAPK only partially reverses this effect on IL‐8 production. Consistently, 25‐OH activates Akt in RPE cells, whereas only a modest increase on phosphorylated p38 MAPK is observed. Data further indicates that NF‐kB is not involved in IL‐8 production following treatment with 25‐OH. Conclusion 25‐OH increases IL‐8 production in RPE by a mechanism that requires activation of PI3K and p38 MAPK and does not involve oxidative stress. The effectors downstream of Akt and p38 MAPK remain unknown. This IL‐8 increase may account for the proinflammatory properties of cholesterol oxides in retinal diseases, such as AMD. Supported by FCT grants SFRH/BD/19039/2004 and POCI/SAU‐OBS/57772/2004
Quantification of sphero‐cylindrical defocus using refractive data
Authors: TOUZEAU O , GAUJOUX T , KOPITO R , COSTANTINI E , BORDERIE VM , LAROCHE L 
Published: November 2009

Abstract Purpose To compare various indices calculated using refractive data to quantify defocus. Methods Subjective refraction, pupil diameter (Colvard) and asphericity (Orbscan) were prospectively recorded in 200 healthy eyes (including ametropia) of 121 patients. Refractive data were expressed by a sinusoidal curve in one plane (power / meridian) and by a vector in a 3D dioptric power space. The three Cartesian coordinates of the vector respectively represented the spherical equivalent, WTR/ATR component (0°/90° Jackson), and oblique component (45°/135° Jackson). The defocus was quantified by the root‐mean‐square (RMS) value of the power curve and the length of the vector. Correlations between uncorrected visual acuity (UCVA) in LogMAR units and principal parameters including defocus indices and refractive parameters were analyzed. Results The length of the power vector and the RMS index provided the highest correlation with UCVA (rs=0.90 p<0.001 and rs=0.88 p<0.001, respectively), whereas the correlation was less strong for subjective spherical equivalent (rs=0.70 p<0.001) and subjective cylinder (rs=0.30 p<0.001). Correlation was poor for the pupil diameter (rs=0.20, p<0.001); sex and asphericity coefficient showed no significant correlation (rs<0.08 p>0.20) with UCVA. Conclusion The length of the sphero‐cylindrical vector is clinically relevant to quantify the defocus with the aid of a single index using both spherical and astigmatic components of refraction. The UCVA is mainly explained by the ametropia.
Methods of screening
Authors: VUJOSEVIC S 
Published: November 2009

AbstractDiabetic retinopathy (DR) is one of the leading causes of adult blindness in working age population worldwide due to its late diagnosis and treatment. In effort to early detect DR, before visual loss, international guidelines for DR screening recommend an annual fundus examination for all diabetic patients. A variety of techniques can be used to detect and classify DR, including direct and indirect ophthalmoscopy, stereoscopic color film fundus photography, mydriatic and nonmydriatic (NM) digital color and monocromatic photography. Although ophthalmoscopy is the most commonly used technique to screen for DR, it has poor sensitivity when performed by nonophthalmologists in nonmydriatic conditions. The sensitivity of direct ophthalmoscopy in detecting proliferative DR is about 50% when performed by non‐ophtahlmologists in NM conditions. Seven‐field stereoscopic color fundus photographies have been considered as reference standard for diagnosing DR in randomized clinical trials. But this method is time consuming with uncertain practicity for widespread screening programs. Several studies have reported sensitivity and specificity in detecting DR and diabetic macular edema (DME) using limited number of fundus fields, proposing an alternative method for diabetic retinopathy evaluation to the ETDRS 7 fields. Recently introduced telemedicine screening programs based on digital images have the potential to allow for increased detection of DR, resulting in timely treatment and preservation of vision. Also important cost savings have been reported with DR screening, either by manual (human) or automatic (computer‐based) grading. Therefore, there is a critical need for a sensitive, specificic and cost‐effective screening method.