bluuebunny/crossref_metadata_2025 huggingface dataset:
Drusen in adaptive optics and SD‐OCT
Authors: MASSAMBA N , LAMORY B , SOUBRANE G
Published: September 2009

Purpose The study objective was to explore the microscopic structure of soft macular drusen and surrounding retinal areas using an adaptive optics (AO) camera and to compare the findings to those from standard clinical examinations.

Methods 18 patients of age between 65 and 85 and presenting soft macular drusen were recruited after aninitial scanning laser ophthalmoscope (SLO) examination. We used an AO flood‐illumination system to acquire high‐resolution images of selected drusen areas. Every acquisition provided a series of 20 consecutive reflectance images, out of which 10 were numerically averaged to produce an enhanced final image. The resulting AO images were analyzed in comparison with conventional infrared and autofluorescence fundus images and spectral optical coherence tomography scans.

Results The soft drusen were visible in AO images as generally round areas delimited by a peripheral low‐reflectance line. Hyper reflective spots of size comprised between 2 and 15 μm were observed in many drusen inner areas. These bright spots were sometimes isolated, sometimes grouped into tight aggregates of 2 to 40 components. Cone photoreceptors were visible in areas between drusen in most AO images.

Conclusion The microscopic structures observed in the AO images of soft drusen presents analogies with their described anatomopathologic characteristics, which could not be identified using other in vivo imaging techniques. AO technology could help to refine the clinical classification of macular drusen and obtain deeper insight in their link with the development of different types of advanced AMD. Author Disclosure Information: N. Massamba, None; B. Lamory, Imagine Eyes, G. Soubrane, None.
Comparison of macular pigment optical density (MPOD) between a northern European and a Mediterranean population
Authors: TSIKA C , MAKRIDAKI M , PLAINIS S , TSILIMBARIS M , PALLIKARIS IG
Published: September 2009

Purpose To investigate the Macular Pigment Optical Density (MPOD) differences between a northern European and a Mediterranean population.

Methods MPOD was measured psychophysically using Heterochromatic Flicker Photometry in 71 healthy subjects from northern Europe (18 Dutch and 53 British). 74 healthy age‐matched Cretans (Greece) underwent the same measurements according to the same protocol. None of the subjects was taking any carotenoids supplements. The comparison of MPOD between the two populations was statistically assessed with a Generalized Linear Model of regression. The effect of age and gender was taken into consideration.

Results The mean MPOD of the northern Europe population was 0.43 (CI 95% 0.39‐0.47) and the mean age 45 years old (±19). No effect of age (p=0.402) or gender (p=0.074) was revealed into this group. Respectively, for the Mediterranean population the mean MPOD was 0.42 (CI 95% 0.38‐0.45) and the mean age 39 years old (±17);mean MPOD of this group didn’t seem to change with age (p=0.402) or be affected by gender (p=0.511) either. No statistically significant difference in the MPOD between the two populations was revealed from the analysis (p=0.455). No sex or age effect was observed in the total population (p=0.893, p=0.094 respectively).

Conclusion The MPOD was compared between two populations with different levels of light exposure and theoretically different diet. Although these factors are believed to affect the levels of MPOD, the latter didn’t seem to differ significantly between the two groups in the present study. Additionally, the MPOD levels weren’t found to change with age in either group or in the total population. Similarly, no sex differences were observed.
Verteporfin encapsulated in cationic liposomes as an alternative drug for PDT
Authors: RANJBAR M , MARTIN G , AGOSTINI HT
Published: September 2009

Purpose Cationic liposomes bind specifically to activated endothelial cells like tissue affected by inflammation. They can be loaded with various drugs and are used as a drug carrier system to reach a locally higher concentration of the drug. We used photodynamic therapy (PDT) to compare the established verteporfin (Visudyne®) with cationic liposome‐bound verteporfin (Lipovert) in laser‐induced choroidal neovascularization (L‐CNV) of mice.

Methods Cationic liposomes were loaded with verteporfin (resulting in Lipovert). C57BL/6 mice underwent Argon laser coagulation on day 0 (d0). Lipovert or verteporfin were injected into the tail vein on d10. The CNVs were irradiated with non‐thermic red light (689 nm) 1 min (verteporfin) or 60 min (Lipovert) after injection as pre‐experiments showed the accumulation peak of the drugs during that time. Animals were perfused with FITC‐dextran at d12, d14 or d17. Choroido‐scleral flat mounts were prepared for quantification of the CNV by measuring the area of FITC‐dextran positive vessels.

Results The mean CNV areas of mice treated with Lipovert or verteporfin were clearly reduced to about half of the control. Lipovert was slightly more effective than verteporfin.

Conclusion In our experiments, Lipovert can be substituted for verteporfin. Therefore, it has the potential as a drug for photodynamic therapy. As Lipovert accumulates specifically at the sites of activated endothelial cells, it may show less side effects.
Quantification of neuronal cells in healthy rat retinas by flow cytometry
Authors: TSOKA P , PAPADAKI E , PALLIKARIS IG , TSILIMBARIS M
Published: September 2009

Purpose The primary purpose of this study was to evaluate the potential to quantify the different neuronal populations in the retina of healthy Sprague–Dawley rats in an accurate quantitative way by using flow cytometry.

Methods Rats were killed and the eyes were enuclated to achieve retinal dissection. Tissue dissociation was accomplished with trypsin. After trypsin action was blocked the cells were mechanically dissociated into a single‐cell suspension by gentle pippeting. The cells were permeabilized and stained with the primary antibody. This incubation was followed by another one with a blocking antibody and finally the cells were incubated with the secondary antibody. At least 100.000 healthy cells were analyzed with a FACScalibur and FlowJo software. Dead cell and cell debris were exluded from analysis by gating with forward scatter and side scatter as indicators. The primary antibodies were anti‐rhodopsin against photoreceptors, anti‐Protein Kinace C against bipolar cells, anti‐calbindin against horizontal cells and anti‐microtubule associated protein 1 against ganglion cells. All the primaries antibodies were monoclonal and the secondary antibody was goat anti‐mouse Alexa Fluor 594.

Results Quantification of the above populations was possible using flow cytometry. In this preliminary study, the photoreceptors had the 53.99%, the ganglion the 7%, the bipolars the 4% and the horizontal the 1.15% in the hole mixed retinal population. All experiments were repeated six times.

Conclusion Flow cytometry can be used to quantify the different neuronal populations in control healthy eyes and this verification will be very useful in future in studies in apoptosis or proliferation of these cells.
Role of HSP70 and p62 in regulation of autophagy clearance in ARPE‐19 cells
Authors: KAARNIRANTA K
Published: September 2009

Purpose A hallmark of RPE cell aging is lysosomal lipofuscin accumulation reflecting a weakened capacity for protein degradation in lysosomes. The presence of lipofuscin increases the misfolding of intracellular proteins, which evokes additional stress in the RPE cells. If the capacity of molecular chaperones to repair protein damages is overwhelmed, then the proteins are mainly cleared in proteasomes or in lysosomes including autophagy. We demonstrate that autophagy is a master clearance mechanism in proteasome inhibitor ‐induced aggregation in ARPE‐19 cells.

Methods The HSP70, p62 and ubiquitin expression levels and localization were analyzed by western blotting and immunofluorescense. Confocal and transmission electron microscopy were used to detect cellular organelles and to evaluate morphological changes. HSP70 and p62 levels were modulated using RNA interference and overexpression techniques. Cell viability was measured by colorimetric assay.

Results The proteasome inhibitor MG132 evoked the formation of juxtanuclear protein aggregates in ARPE‐19 cells. It also caused a robust accumulation of HSP70 and p62 proteins and ubiquitin‐protein conjugates that all colocalized with the formed protein aggregates. We found that protein aggregation is a temporary process, a cessation of proteasome inhibition led to autophagosome‐mediated removal of cytoplasmic protein aggregates. Interestingly, the p62 rather than the HSP70 regulate autophagy activity. However, both of them have essential function in regulation of cellular viability.

Conclusion In addition to classical lysosomal proteolysis, there is the increasing evidence that heat shock proteins, proteasomes and autophagy regulate protein turnover in the RPE cells and thus have important roles in AMD disease.
Intravitreal bevacizumab for choroidal neovascularization secondary to angioid streaks: one year follow‐up
Authors: KORT F , BOURAOUI R , CHEBIL A , CHAKER N , CHAABOUNI A , MGHAIETH F , EL MATRI L
Published: September 2009

Purpose To evaluate the efficay and safety of intravitreal bevacizumab at one year follow‐up, for the treatment of choroidal neovascularization (CNV) associated with angioid streaks.

Methods Consecutive series of 16 eyes with subfoveal or juxtafoveal CNV secondary to angioid streaks, treated with intravitreal bevacizumab (1.25 mg in 0.05 ml) between January 2007 and March 200, were reviewed retrospectively. Ophthalmic examination including best corrected visual acuity (BCVA), optical coherence tomography (OCT) and fluorescein angiography, was performed before and after treatment. Retreatment was given every six weeks in case of persisting symptoms or CNV activity on OCT. The main outcome measures were changes in BCVA and central retinal thickness on OCT at the 1‐year follow‐up.

Results The mean number of injections was 4.6 at one year. Ten eyes (62.5%) received more than five injections. The mean BCVA at baseline was 20/81 (range 20/400 to 20/32) and improved to 20/40 (range 20/100 to 20/20) at one year (p=0.055). The BCVA improved by three or more lines in ten eyes (62.5%) and remained within two lines of baseline in six eyes (37.5%). Mean central retinal thickness was 404.2µm at baseline (range 160 to 602 µm) and decreased to 293.3µm (range 150 to 490µm) at one year (p=0.006). No ocular or systemic complications were noted.

Conclusion The one‐year outcomes suggest intravitreal bevacizumab to be a promising treatment for CNV associated with angioid streaks, resulting in both functional and anatomical improvements. Repeated injections are needed to maintain these results.Further controlled, prospective and long term evaluations of this treatment are warranted.
TNFα suppresses IFNγ‐induced MHC Class II expression in retinal pigmented epithelial cells by down regulating Class II trans‐activator mRNA
Authors: MAKHOUL M , BRUYNS C , KOCH P , CASPERS L , WILLERMAIN F
Published: September 2009

Purpose The expression of MHC class II molecules induced by IFNγ on RPE cells plays a crucial role in the development of autoimmune uveitis. As TNFα is commonly coexpressed with IFNγ in this disease, we have investigated the effects of TNFα on the IFNγ mediated MHC II induction in RPE cells.

Methods ARPE‐19 were cultured and stimulated with TNFα, IFNγ, IL‐1β and different combination of these cytokines. After cytokine treatment, we have analysed the expression of MHCII and ICAM‐1 by flow cytometry. IDO induction was studied by Western blotting. The activation and expression of two proteins involved in IFN pathway: IRF1 and STAT was analysed by Western blot. We have also monitored the effects of TNFα and IFNγ on the expression of CIITA by quantitative RT‐PCR.

Results TNFα, but not IL‐1, inhibits IFNγ induced MHC class II expression on the surface of ARPE cells. We did not observed an inhibitory effect of TNFα on the expression of ICAM and IDO induced by IFNγ. Similarly, STAT1 phosphorylation and IRF1 induction obtained after IFNγ treatment were not affected by TNFα. On the contrary, we found that TNFα suppresses IFNγ induced CIITA mRNA accumulation.

Conclusion TNFα suppresses IFNγ induced CIITA mRNA accumulation and MHC II expression in human retinal pigment cells.
Comparative assessment of S. aureus microbial biofilm inhibition by an N‐alkyl‐polyethyleneimine covalently attached to PMMA or titanium in the Boston Keratoprosthesis
Authors: BEHLAU I , MUKHERJEE K , TODANI A , KLIBANOV AM , GILMORE MS , DOHLMAN CH
Published: September 2009

Purpose Biofilms are matrix‐associated microbial communities adherent to either biological surfaces or abiotic surfaces. They account for the majority of device‐associated infections. Our goal herein is to minimize bacterial adherence and biofilm formation by comparative analysis of new polycations bound to bio‐prosthetic ocular‐associated materials, poly (methyl methacrylate) (PMMA) or titanium, using the Boston KPro as a model system.

Methods Using S.aureus ocular‐associated clinical isolates, a quantitative assessment of microbial biofilm formation by linear N,N‐dodecyl,methyl‐polyethyleneimine (DMPEI) (217 kDa) covalently bound to PMMA or titanium compared to the parent PMMA or Ti, respectively, has been performed using confocal laser scanning and electron microscopies. In addition, DMPEI‐bound materials have been screened for corneal toxicity in both cell tissue culture and rodent models, and as compared to the original materials.

Results A marked inhibitory effect in S. aureus biofilm formation on DMPEI‐derivatized materials compared to the parent PMMA (3‐4 fold) and Ti (2‐fold), without conferring additional epithelial cell cytotoxicity in vitro, has been observed. Furthermore, we have found no additional tissue reactivity, and possibly even a protective effect, with DMPEI‐derivatized materials in vivo.

Conclusion We found that covalent derivatization with DMPEI of PMMA and Ti greatly reduces S. aureus biofilm formation in vitro compared to the parent materials. There was no additional cytotoxicity seen both in vitro and in vivo. Future studies will evaluate DMPEI‐derivatized materials for in vivo antimicrobial efficacy.
Macular edema and neovascularization in a case of Stargardt macular dystrophy
Authors: KARAMPATAKIS V , VOUTAS S , LAKE S , KORDALI P
Published: September 2009

Purpose To present a case of macular edema and neovascularization in a patient who was diagnosed with Stargardt macular dystrophy.

Methods We present the case of a 22 year old male who experienced visual deterioration in his left eye. At presentation his visual acuity was OD 8‐9/10 and OS 6‐7/10. OCT scan, fluoroangiography (FA) and electroretinografy (ERG), were performed.

Results OCT scan revealed cystoid macular edema in the right eye, and increased reflectivity of the pigment epithelium and some subretinal fluid in the left eye. FA findings were consistent with Stargardt dystrophy. However in the right eye an area of increasing hyperfluorescence was observed (presence of neovascularisation). ERG: subnormal photopic and scotopic responses. The color vision was impaired mainly in the left eye. Following the experience of other investigators acetazolamide was administered orally (300 mg per day) and resolution of the cystoid edema was obvious in OCT scan after 20 days. The visual acuity increased (OD 10/10 and OS 8/10). Two weeks after the discontinuation of acetolozamide the macular edema reappeared and the visual acuity diminished: OD 8‐9/10 and OS 6‐7/10.

Conclusion This is a peculiar case of cystoid macular edema and neovascularization in Stargardt macular dystrophy. Our findings suggest, in consistency with other investigators, that administration of oral acetozolamide may be beneficial for the resolution of macular edema. The neovascularization in the left eye remained stable during the follow up period and it was considered that any intervention was not necessary at that time.
Sudden loss of vision 15 years after renal transplantation
Authors: COUPLAND SE , THUMANN G
Published: September 2009

Abstract not provided
Treatment of neovascularization myopic with ranibizumab: 18‐month results
Authors: EGEA ESTOPINAN MC , TORRON FERNANDEZ‐BLANCO C , GUERRI MONCLUS N , PRIETO CALVO E , FERRER NOVELLA E , RUIZ MORENO O , PABLO LE
Published: September 2009

Purpose To evaluate the efficacy of intravitreal Ranibizumab as treatment for choroidal neovascularisation due to pathological myopia

Methods A retrospective, non‐comparative study of 21 eyes treated with intravitreal injections of Ranibizumab. Ten eyes had been treated previously with photodynamic therapy and eleven received Ranibizumab as first therapy. After thorough ophtalmologic examination, fluorescein angiography (FAG) and optical coherence tomography (OCT) intraocular injection was practised, a new treatment was decided according to the subjective impression of the patient, visual acuity, presence or absence of metamorphopsia, biomicroscopy and OCT examination.

Results Twenty one eyes from 17 patients were finally included. Patients were followed up for 18 months. The mean age at initial treatment was 55.71 years. Mean refractive error was ‐12.6 diopters. Regarding AGF all neovascular membranes were classical and sub or yuxtafoveal localised. At the end of the 18 months after treatment 16 eyes (76.19%) showed better visual acuity ranging from one or more lines on Snellen chart, 10 eyes(47.61%) improved two lines or more, 4 eyes(19%) did not show any changes and one eye(4.76%) worsened two lines. At 18 months the mean best‐corrected visual acuity (BCVA) improved from 0.28 to 0.50 (p= 0.001). The mean central macular thickness decreased

Conclusion Ranibizumab may be a good therapeutic option as treatment for choroidal neovascularisation due to pathological myopia, it improved visual acuity and anatomical features, even in non‐responders to photodynamic therapy.
Age‐related macular degeneration: hemodynamic changes
Authors: POURNARAS CJ , POURNARAS JAC , MENDRINOS E
Published: September 2009

Purpose Metabolic changes of the RPE associated to the dysfunction of choriocapillaries(CC)/RPE complex may induces the AMD‐related changes. Additional vascular changes in the choroid potentially have deleterious effects on the RPE.

Methods Quantification of CC number and lumen diameters in cross sections and alkaline phosphatase (APase) flat‐embedding technique, expressing high constitutive APase activity in choriocapillaris and choroidal veins on human RPE/Bruch’s Membrane/CC complex, significantly contributed to the analysis of the choroidal vasculature. Laser Doppler flowmetry (LDF) data provided additional information on the assessment of hemodynamic changes in AMD.

Results Choroidal vascular density reduction and significant vasoconstriction of the choriocapillaries, occurs during the evolution of AMD. In eyes with geographic atrophy, the RPE degenerates first while CC loss is secondary to RPE degeneration. In eyes with exudative AMD, degeneration of the CC layer occurs while RPE is still functional. LDF data indicated choroidal blood flow decrease according to age and the degree of severity of AMD; the decrease in flow preceding the formation of choroidal CNV, strongly suggest that these changes may have a role in the development of CNV. As a result of vascular dysfunction, the choroidal blood flow is dysregulated in patients with neovascular AMD. The choroidal watershed zone (WZ) courses through the fovea more often in patients suffering from AMD than in age‐matched controls, particularly in the presence of CNV. Choroidal neovascularisation usually arises within these WZ.

Conclusion The role of choroidal ischemia in the pathophysiology of AMD is supported by the observed choroidal microcirculation anatomical and fucntional abnormalities.
Biosynthetic corneas – evaluation in humans
Authors: FAGERHOLM P , LAGALI N , GRIFFITH M
Published: September 2009

Collagen‐based biosynthetic corneas, designed to mimic the extracellular matrix of the corneal stroma have been developed and extensively evaluated in animal models over the last 7 years. Human recombinant collagen type III (RHC III) was crosslinked with water‐soluble carbodiimides and fabricated into optically transparent corneal substitutes for transplantation. Following study approval of the Medical Product Agency, Sweden and the Human Ethics Committee, University of Linköping, Sweden, a Phase I study was initiated. 10 patients who were scheduled for corneal grafting were enrolled into the study. Nine had keratoconus and one had a deep scar following Pseudomonas keratitis. A central 6 mm diameter deep lamellar button was excised and was replaced by a 6.25 mm diameter 500 µm thick construct. Six overlying sutures were used to anchor the graft. Topical 0.1% dexametasone and chloramphenicol was used for the first 1 month postoperatively. The sutures were removed after 5‐7 weeks. The patients were followed clinically and evaluated for UCVA, BSCVA and VA with contact lenses. Corneal touch sensitivity (Cochet‐Bonnet) and tear production (Schirmer ) were tested. Photography, OCT (Visante), topography (Orbscan II) and in vivo confocal microscopy (Heidelberg) was documented. After 3 months all patients had stably epithelialized and implants were anchored by recipient keratocyte ingrowth. The mean BSCVA at 6 months (20/133) improved slightly at 12 months (20/90). The mean BCLCVA was 20/50 at 12 months and was notably better in younger patients (mean of 20/40 in the 5 youngest). One patient had BCLVA of 20/20 at 12 months. The mean central corneal thickness was stable between 3 and 12 months at about 400µm.The mean 5min Schirmer values were 20 ± 10mm in operated eyes and 17 ± 8 mm in fellow eyes. At 12 months the mean touch sensitivity was 25mm in operated eyes and 60mm in fellow eyes, which was the same as in penetrating grafts. In‐vivo confocal microscopy revealed the ingrowth of corneal nerves at the subbasal epithelium. We have shown for the first time that bioengineered collagen‐based corneal substitutes are fully compatible and promote regeneration of corneal cells. The 18 months follow‐up results will be presented aswell.
Improving the optics of KPros
Authors: HULL C , GOMAA A , LIU C
Published: September 2009

Purpose The purpose of this talk is to review the clinically relevant optical and visual requirements of keratoprostheses.

Methods Modelling of designs using commerical and purpose‐written optical design software as well as clinical measurments on a small number of patients implanted with the osteo‐odonto keratprosthesis optical cylinder.

Results The important visual optical proerties of any keratoprosthesis optic are the foveal image quality (affecting the acuity) and the field of view. These fundamentally depend upon the pupil size, and the length and diameter of the optic since the power must be fixed to give emmetropia. The axial image quality can be changed by controlling the spherical aberration. However, maximising axial (foveal) image quality causes poorer off‐axis image quality potentially reducing the effective visual field. Shorter, larger diameter optics help improve the visual field as well as consideration of off‐axis image quality.

Conclusion The theoretical properties of keratoprosthesis optics must be balanced against other clinical requirements such as longterm complications and stability. The clinical requirements provide the constraints on the optical design. However, discussions can usefully happen between surgeons and those involved in the design of the optics to give the best possible visual rehabilitation.
The clinical psychologist’s role in the OOKP clinic. A one year review
Authors: BUSUTTIL A , HOIT C , CAMIC P , GOMAA A , HEROLD J , THORP S , LIU C
Published: September 2009

OOKP Surgery places complex Physical and Psychological demands on patients. Attention to Psychological factors is likely to facilitate good outcome and improve Quality of Life. This presentation outlines an innovative addition to the OOKP service at Sussex Eye Hospital, Brighton UK, incorporating a Clinical Psychologist as a member of the OOKP medical team. It will describe the first year's work including a study which has identified four subgroups of patients presenting for OOKP and the psychological needs of each group. The presentation describes how the service aims to address the particular psychological needs of these patient groups from assessment to psychological follow up. The presentation will also include a summary of a second Qualitative Interview study looking at patients' reports of their experiences of undergoing OOKP from a bio‐psychosocial perspective.The National Health Service, UK seeks to use patient experience and feedback to shape clinical services and the implications of the outcomes of the research for the service will be discussed.
Repeatability of retinal nerve fiber layer and macular thickness measurements using Cirrus Fourier‐domain optical coherence.
Authors: GARCIA MARTIN E , PINILLA I , IDOIPE M , GIL ARRIBAS L , FUERTES I , PUEYO V
Published: September 2009

Purpose To test intrasession, intersession, intervisit, and interoperator reproducibility of retinal nerve fiber layer (RNFL) measurements and retinal thickness using Cirrus Fourier‐domain optical coherence tomography (OCT).

Methods Seventy‐two eyes of 72 healthy subjects underwent three macular 512x128 volume cube centered on the fovea and three 360° optic disc circular scans done by the same observer. This sequence was repeted by another observer on a second visit within a 2‐week period. Descriptive statistics, analysis of variance, intraclass correlation coefficients (ICC), and coefficients of variation (COV) were calculated for the 9 macular areas described by the Early Treatment Diabetic Retinopathy Study (ETDRS) in the macular protocol and for quadrants and RNFL clock hour sectors.

Results All measurements were highly reproducible. The ICCs ranged from 0.823 to 0.992 using macular volume cube and from 0.886 to 0.984 with optic disc cube protocol. Mean differences between both operators were lower than 3 μm in all measurements and no significant differences were found. Total retinal thickness mean was 285.17 ±15.31 μm by observer 1 and 284.20 ±12.89 μm by observer 2. Mean COV was 1.2 ±0.99% (ranged from 0.5 to 1.8%) for the nine ETDRS areas. Lowest COV was found for the nasal inner area. Mean RNFL average thickness was 95.99 ±7.67 and 95.72 ±7.87 μm by observer 1 and 2, respectively. Mean COV was 4.41 ±3.01% (ranged from 1.43 to 6.66%).

Conclusion Retinal and RNFL thickness measurements obtained using Cirrus Fourier‐domain OCT show good reproducibility for healthy eyes. The device is an important tool for to the diagnosis and follow‐up of retinal and optic nerve pathologies.
Introduction
Authors: HERBORT CP
Published: September 2009

Abstract not provided
Serpiginous choroiditis revisited
Authors: MACKENSEN F
Published: September 2009

Purpose Serpiginous Choroiditis (SC) is a subtype of posterior uveitis with often unfavorable visual prognosis, often requiring intensive immunosuppressive treatment. Histological and clinical evidence has been reported linking tuberculosis to cases of chorioiditis and specifically to serpiginous‐like chorioiditis . A potential tuberculous origin is of concern as the treatment would be completely different. Tuberculin skin test has limited power for diagnosing tuberculosis since active disease cannot be differentiated from immunity and because of cross‐reactivity with bacillus Calmette‐Guérin (BCG). It is one of the oldest diagnostic tests still in use worldwide with variable sensitivity and specificity depending on the cut‐off used and the population screened.Therefore, we used an interferon‐γ release assay (QuantiFERON TB‐Gold; Cellestis, Australia) to obtain a diagnosis of tuberculosis in patients with serpiginous like chorioditis.

Methods Quantiferon is an approved, antigen‐specific test that utilizes synthetic peptides representing M. tuberculosis proteins. After incubation, interferon‐γ secreted by T‐lymphocytes in response to these antigens is measured.

Results In our cohort 52 % of SC patients were tested positive. Patients with SC also showed higher absolute Tb antigen responses as compared to Quantiferon positive patients with other uveitis subtypes.

Conclusion Our findings support a tuberculous origin in SC. Other groups also found evidence of Tb association with SC, proven by radiologic imaging. These patients seem to improve with anti‐Tb treatment. The diagnostic significance of Quantiferon and other Tb testing in patients with SC and treatment implications will be discussed.
Significance of autofluorescence in choriocapillaritis
Authors: MANTOVANI A , HERBORT CP
Published: September 2009

Purpose To investigate the autofluorescence findings associated with choriocapillaritis

Methods Illustrative cases of Primary Inflammatory Choriocapillaropathies(PICCPs)including Multiple Evanescent White Dot Syndrome (MEWDS), Acute Placoid Multifocal Pigment Epitheliopathy (APMPPE) or Multifocal Choroiditis (MFC), where Fundus Autofluorescence(FAF) images were obtained in the short wave mode(488nm), lipofuscin‐related, or in near‐infrared mode(787), melanin‐related.

Results In the groups of MEWDS and MFC patients, the more striking FAF alteration is an increase in autofluorescence. The areas of FAF do not strictly correspond to areas of ICGA hypofluorescence, with less FAF in areas of more pronounced ICGA hypofluorescence. The areas of increased FAF regress almost totally in the convalescent stage. In the APMPPE group, the placoid lesions are very often hypoautofluorescent except the margins that can be hyperautofluorescent. In the convalescent stage, altered FAF regresses, but bright FAF is often seen in the center of chorioretinal scars, corresponding to accumulation of fluorophores debris.

Conclusion FAF is a complementary imaging technique in PICCPs indicating RPE cell dysfunction, but the information we have so far is scarce and has to be elucidated. In less severely hypoperfused areas,such as MEWDS and MFC, FAF488 is increased because the metabolism of the RPE cell is affected, which explains the accumulation of lipofuscin in its lysosomes. In conditions with severely nonperfused areas, such as APMPPE, FAF488 is very often decreased because RPE cell metabolism is probably affected to such a degree that it does not ingest any more lipofuscin and does not cause autofluorescence.
Clinically useful wide‐field high‐resolution retinal imaging optics with a dual‐conjugate adaptive instrument
Authors: SJÖSTRAND J , KNUTSSON P , POPOVIC Z , THAUNG J
Published: September 2009

Purpose The aim of this project is to apply the technique of multi‐conjugate adaptive optics (MCAO) for high‐resolution imaging of the retina over a wide field‐of‐view (FOV).

Methods MCAO is the principal technique to overcome the limitations of conventional AO systems by increasing the corrected FOV. The current system incorporates two deformable mirrors (DMs). Optically, these two DMs correspond to separate planes along the optical axis of the eye. This allows the correction of field‐dependent aberrations and subsequent wide‐field high‐resolution retinal imaging over a wide FOV. Normative data from healthy subjects was collected in order to determine clinical potential and limitations.

Results We have demonstrated the MCAO concept with a current FOV of 7x7 deg on both model and human eyes. The diffraction‐limited resolution is around 2 µm on the retina, allowing most cone photoreceptors to be resolved. Retinal morphology of healthy subjects was investigated. The estimated cone separation at a retinal eccentricity of 1.2 deg and 2.5 deg from the fovea was 6 µm and 9 µm, respectively, in agreement with the literature. The relatively narrow depth of focus enables us to image different layers of the retina. Focusing on deeper layers allows us to image the cone photoreceptor layer. By focusing on the upper layers we can also image the retinal capillary layer and nerve fibre layer with the same high resolution.

Conclusion Our instrument allows retinal features down to 2 µm to be resolved over a 7x7 deg FOV. We believe that this new technique has a future potential for clinical imaging with an impact particularly important for early diagnosis of retinal diseases.
Local and genetical determinants of vascular endothelial growth factor in vision threating proliferative diabetic retinopathy
Authors: GLOBOCNIK PETROVIC M , HAWLINA M , KOSNIK M , KOROSEC P , PETROVIC D
Published: September 2009

Purpose To search for the association between the –634 C/G polymorphism of the VEGF gene and vision threating proliferative diabetic retinopathy (PDR) and to determine whether vitreous levels of VEGF were affected by genetic factors.

Methods In this cross sectional case‐control study 349 unrelated Slovene subjects (Caucasians) with type 2 diabetes mellitus were enrolled: 206 patients with vision threating PDR in whom vitrectomy was performed, and the control group of 143 subjects with type 2 diabetes of duration of more than 10 years who had no clinical signs of diabetic retinopathy. In 68 out of 206 patients with PDR (71 eyes) vitreous fluid samples (0.3 ml) were obtained by vitreoretinal surgery.

Results The –634 C/G VEGF gene polymorphism was not associated with PDR. Moreover, significantly higher vitreous levels of VEGF were demonstrated in diabetics with the CC genotype compared to those with the other (CG + GG) genotypes.

Conclusion Despite the effect of the –634 C/G VEGF gene polymorphism on vitreous levels of VEGF in PDR, it failed to contribute to the genetic susceptibility to PDR.
Visual function vs quality of life assessment in patients with laser‐treated diabetic macular oedema
Authors: PEARCE L , SIVAPRASAD S , CHONG V
Published: September 2009

Purpose To compare different visual function assessments in patients with laser‐treated diabetic macular oedema (DMO) to the self‐assessment of visual dysfunction and quality of life (QoL) time trade‐off (TTO) utility measures.

Methods Forty patients with DMO previously treated with laser were assessed for best corrected visual acuity (distance and near), reading speed, fixation location and stability, microperimetry with Nidek MP‐1, and optical coherent topography (OCT). Subjective analogue self‐assessment of distance and near visual dysfunction and QoL TTO utility measures were also assessed.

Results Distance visual acuity correlate well with fixation location and stability, and central retinal thickness of OCT. Near visual acuity and reading speed correlate well with relative scotoma size. However, visual dysfunction and QoL TTO utility correlations are more complex, reading speed in the better seeing eye is best to correlate with QoL TTO utility after correcting for age.

Conclusion Laser treated DMO patients often report subjective visual dysfunction that cannot be explained by best corrected distance visual acuity. Scotoma size affects near vision and reading speed, leading to poor quality of life.
Ocular and systemic endothelial function in the offspring of diabetics: a pilot study
Authors: PATEL S , GHERGHEL D , HEITMAR R , BENAVENTE‐PEREZ A , QIN L , MCINTYRE D , BALANOS G , GIBSON J
Published: September 2009

Purpose To investigate ocular and systemic correlates of endothelial function in the normoglycaemic offspring of Type 2 Diabetics (T2DM).

Methods Healthy participants aged between 25‐65 with (n=30) and without (n=39) a family history were recruited. Retinal vessel reactivity was assessed by using the Retinal Vessel Analyser (RVA, Imedos GmBH). In addition, systemic endothelial function was assessed by using the flow mediated dilation (FMD) technique.

Results Parametric testing showed no significant differences in anthropometric, blood assay or ocular and systemic function between both groups (p>0.05). The average maximum dilation in the measured retinal artery correlated significantly with the maximum dilation of the measured brachial artery (p=0.002 R=0.55) in healthy controls; however, this was not true for subjects with family history of T2DM.

Conclusion Subjects with family history of T2DM show possibly early signs of endothelial dysfunction that, in certain conditions, could contribute to the higher risk of this group of developing similar pathology to their parents.
Bilateral central serous chorioretinopathy in a patient with focal segmental glomerulosclerosis
Authors: PRIETO CALVO E , EGEA ESTOPINAN MC , GUERRI MONCLUS N , RUIZ MORENO O
Published: September 2009

Purpose The central serous chorioretinopathy (CSCR) is a frequent ocular disease characterized by a serous detachment of the neurosensory retina at the posterior pole. This sporadic and self‐finished disease can become chronical in some cases, resulting in a degeneration and atrophy of the underlying retinal pigment epithelium (RPE). The more severe cases of CSCR had been recognized in patients treated with high systemic corticosteroid doses and in haemodialysis patients.

Methods A 37‐year‐old‐man was attended in emergency with history of several days of blurring of vision. He was being haemodialysis by chronical renal failure secondary to a focal segmental glomerulosclerosis. The patient presented a visual acuity of 0,4 in the OR and 0,8 in the OL, with an image of bilateral CSCR on the fundus examination that was confirmed by optical coherence tomography (OCT).

Results We reported the chronical evolution of the process until a kidney transplantation was done to the patient, reaching a spontaneous healing. Four and half months after the transplantation, evidences of a disappearance of sub‐retinal fluid with a persistence of drusen‐like retinal pigment epithelial alterations were found in the OCT‐image.

Conclusion Immune‐complex deposits similar to the glomerular deposits can be identified near the Bruch membrane in patients with glomerulonephritis, these deposits prove the RPE‐barrier dysfunction and the appearance of disorders like macular drusens, sub‐retinal fluid or choroidal neovascularization. The case highlights the importance of ophthalmological assessment in these patients to recognise sight‐threatening complications.
Mechanics of a macular hole: formation and surgical closure
Authors: PEDDADA R , WEINBERG D
Published: September 2009

Purpose To elucidate the mechanics of the formation and surgical closure of a macular hole.

Methods A parafoveal insertion of vitreous is examined in relation to its effect on the fovea. A force vector analysis is performed to understand the stages of a macular hole formation. A viscoelastic mechanical model is introduced to interpret the time constant of closure of the hole in terms of the physical properties of retina and the surrounding viscous fluid.

Results Macular hole develops due to a combination of a tangential (radially outward from the fovea) and perpendicular force components arising from the posterior hyaloid separation (insertion) close to the fovea. The perpendicular force leads to the anterior deformation of the fovea, and therefore in cysts and schisis ("cavitation")formation. The subsequent separation of the photoreceptors from the RPE is also a consequence of the same perpendicular force. The loss of contact with the RPE in the presence of a tangential force lowers the resistance to the radially outward deformation of the foveal tissue and eventual hole formation. The hole closure occurs due to the stored elastic energy of the retina. The relaxation of the fovea is slowed or prevented by the viscosity of the surrounding fluid. Therefore, the hole closure may occur as soon as a few hours or it may never occur depending on the residual fluid and its viscosity at the conclusion of the surgery. The contribution of ILM peeling is discussed.

Conclusion Macular hole forms as a consequence of both tangential and perpendicular components of the vitreous traction. The hole closure is promoted by the elasticity of the retina, and retarded by the viscosity of the residual fluid in the foveal region.
AION and glaucoma: similarities and difference
Authors: STALMANS I
Published: September 2009

Purpose Anterior ischemic neuropathy (AION) and glaucomatous optic neuropathy (GON) are two distinct clinical entities, but share some striking similarities.

Methods These similarities between AION and GON are highly suggestive of a common mechanism for the development of the two diseases. Evidence has gradually emerged that there is vascular insufficiency in the optic nerve head (ONH) in both anterior ischemic optic neuropathy and glaucomatous optic neuropathy; thus both represent ischemic disorders of the ONH.

Conclusion During this lecture, the clinical similarities and differences between AOIN and GON will be highlighted, and their potential common pathogenetic mechanisms will be discussed.
Reference values: a review
Authors: Geffré Anne , Friedrichs Kristen , Harr Kendal , Concordet Didier , Trumel Catherine , Braun Jean‐Pierre
Published: September 2009

Abstract: Reference values are used to describe the dispersion of variables in healthy individuals. They are usually reported as population‐based reference intervals (RIs) comprising 95% of the healthy population. International recommendations state the preferred method as a priori nonparametric determination from at least 120 reference individuals, but acceptable alternative methods include transference or validation from previously established RIs. The most critical steps in the determination of reference values are the selection of reference individuals based on extensively documented inclusion and exclusion criteria and the use of quality‐controlled analytical procedures. When only small numbers of values are available, RIs can be estimated by new methods, but reference limits thus obtained may be highly imprecise. These recommendations are a challenge in veterinary clinical pathology, especially when only small numbers of reference individuals are available.
Status Epilepticus and Epileptic Seizures in Dogs
Authors: Zimmermann R. , Hülsmeyer V.‐I. , Sauter‐Louis C. , Fischer A.
Published: September 2009

Background:A special form of epileptic seizures (ES) is the life‐threatening condition of status epilepticus (SE), which requires immediate and specific treatment based on a correct diagnosis of the underlying disease condition.

Hypothesis/Objectives:The objectives of this retrospective study were to determine prevalence of ES and SE in dogs presenting at a veterinary teaching hospital, to identify the etiology and relative risk (RR) for SE in general and at the onset of seizures. Furthermore the outcome for dogs suffering from SE was to be evaluated.

Animals:Three hundred and ninety‐four dogs that were admitted to a veterinary teaching hospital (January 1, 2002 to March 31, 2008) with ES.

Methods:All medical records of dogs with ES were identified by screening the clinical documentation system and evaluated for inclusion in this retrospective study.

Results:Dogs with reactive seizures caused by poisoning had a significantly higher risk of developing SE (P< .001; RR = 2.74), particularly as 1st manifestation of a seizure disorder (P= .001; RR = 1.97). After SE, dogs with symptomatic epilepsy had a significantly lower probability of survival than dogs with idiopathic epilepsy (P< .001) and reactive ESs (P= .005).

Conclusion and Clinical Importance:In dogs showing SE as the 1st manifestation of a seizure disorder, intoxication should always be considered and appropriate investigations undertaken. Dogs with SE owing to toxicosis have more favorable outcomes than dogs with symptomatic epilepsy (P< .001).
A Simulation Model of a Four-Stroke Spark Ignition Engine Fueled With Landfill Gases and Hydrogen Mixtures
Authors: Narayanan Guruprasath , Shrestha S. O. Bade
Published: September 2009

A simulation model for establishment of performance parameters of a spark ignition engine fueled with landfill gas, methane, and landfill gas-hydrogen mixtures is described. A two zone model was employed to estimate combustion duration, ignition lag, associated mass burning rates, and performance parameters for various operating conditions in an internal combustion engine. The modeling consists of two main modules: (a) a fuel-air and residual gas properties calculation, and (b) equilibrium combustion product properties calculation with 13 species of equilibrium combustion products. The fuel-air and residual gas module calculates gas properties required in compression stroke and the unburned zone of a combustion chamber. The equilibrium combustion products module calculates gas properties for the burned zone during combustion and expansion phases. In addition to engine parameters, combustion duration estimation methods were presented to accommodate the presence of high quantities of diluents such as carbon dioxide and nitrogen in methane to represent landfill gases, generally encountered in practice. Similarly, an effect of the addition of hydrogen in landfill gas on performance of a spark ignition engine was also incorporated in the model. The pressure traces and engine power output parameters were modeled and compared with the experimental observations obtained in a variable compression single cylinder four-stroke spark ignition co-operative fuel research engine for different fuels that include methane, landfill gas, and landfill gas-hydrogen mixtures and found satisfactory agreement. MATLAB was used as the programming software in the model.
Thermodynamic Equilibrium Model and Exergy Analysis of a Biomass Gasifier
Authors: Srinivas T. , Gupta A. V. S. S. K. S. , Reddy B. V.
Published: September 2009

Biomass gasification involves the production of a gaseous fuel by partial oxidation of a solid fuel. Clean synthesis (syn) gas, produced from partial combustion of biomass, can be burnt in a gas turbine combustion chamber to run a biomass based combined cycle power plant. A thermochemical model has been developed to predict the gas composition and performance of a biomass gasifier based on thermodynamic equilibrium concept for different biomass materials. A simplified numerical method is applied to solve the thermochemical equilibrium reactions. The system consists of a pressurized circulating fluidized bed to produce the syn gas from the biomass. The effect of the relative air fuel ratio (RAFR), steam fuel ratio (SFR), and gasifier pressure has been examined on the gas composition, gasifier temperature, lower heating value of syn gas, and exergy efficiency of biomass gasifier to obtain a high yield from the biomass. It has been found that at lower values of RAFR and SFR, the heating value of the syn gas and the exergy efficiency of gasifier is high.
Inflow Performance Relationships Under Gravity Segregation for Solution Gas-Drive Reservoirs
Authors: Padilla-S. Roberto , Camacho-V. Rodolfo G. , Castrejón-A. Rafael , Samaniego-V. Fernando
Published: September 2009

This paper analyzes the influence of gravity segregation effects on inflow performance relationship (IPR) curves, with both totally and partially penetrated vertical wells. Using synthetic responses from a finite difference simulator, the effects of different parameters, such as vertical to radial permeability ratio, production mode, position of productive interval, oil rate, and mechanical skin, on the shape of IPR curves are documented. It is shown that greater flow potentials are obtained when the ratio of gravity to viscous forces increases. It is shown that for the case of partially penetrated wells, the IPR curve generated at constant bottomhole pressure does not coincide with the IPR generated at constant oil rate. Also, the presence of gravity segregation affects the values of absolute open flow potential, obtaining big differences with the corresponding values when gravitational effects are ignored. The values of the exponent n of Fetkovich IPR and the coefficients of the quadratic equation proposed by Jones et al. are functions not only of time but also of production rate, position of productive interval, and other parameters. The consequence of the above results is that the interpretation of IPR curves is affected by the presence of gravitational effects and therefore the use of traditional methods, such as those of Vogel , Fetkovich, or Jones et al., is restricted to the specific conditions considered by these authors.