bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uveal melanoma clonogenic response to proton beam irradiation
Authors: Romanowska Dixon B. , Jasinska K. , Michalik M. , Madeja Z. , Urbańska K. , Elas M. 
Published: September 2016

PurposeThe goal of this study was to compare the cellular clonogenic response to proton beam and X‐ray irradiation of uveal melanoma cell line Mel270 and human melanoma cell line BLM.MethodsBLM line was derived from a skin melanoma metastasis to the lung, and Mel270 is a primary uveal melanoma cell line. Cells were irradiated with 1–5 Gy of X ray (300 kVp Phillips, 1 Gy/min) or proton beam (60 MeV) from Proteus C‐235. After irradiation cells were seeded for the clonogenic assay. Two weeks after seeding the number and type of clones were determined. Three types of clones were found: the largest in size holoclones (with the highest potential to proliferate), medium sized meroclones and the smallest paraclones (low potential to proliferate).ResultsThe total number of clones were similar for both cell lines and both types of irradiation. The RBE values calculated for 37% of survival fraction were 1.11 and 1.13 for Mel270 and BLM cells, respectively. Three types of clones seen in untreated cultures imply the heterogeneity of cellular populations. After irradiation the proportion between the three types of clones was changed: the number of holoclones was drastically lower, and the number of paraclones increased. The number of paraclones was lower after proton bean irradiation in comparison to X‐rays in both cell lines.ConclusionsProton beam and X‐ray irradiation differently modify the proliferation potential of melanoma cells.
Optimization of storage of differentiated retinal pigment epithelial cells
Authors: Khan A.Z. , Utheim T.P. , Reppe S. , Sandvik L. , Lyberg T. , Roald B.B.H. , Eidet J.R. 
Published: September 2016

PurposeThe advancement of human retinal pigment epithelial (HRPE) cell replacement therapy for retinal blindness is partly dependent on optimization of cell culture, cell preservation, and storage medium. This study aims at optimizing the storage temperature and storage medium for HRPE cells.MethodsHRPE cells were cultured under standard conditions and randomized for storage at six temperatures (4°C, 16°C, 20°C, 24°C, 28°C, and 37°C) for seven days. After finding the optimal storage temperature, HRPE cells were subsequently stored at 4°C with and without the silk protein sericin added to the storage medium. Live dead assay was performed on all cell cultures including the unstored control cells. The phenotypic expression of premelanosomal protein‐17 (Pmel17), cellular retinaldehyde binding protein (CRALBP), tyrosinase, and proliferating cell nuclear antigen (PCNA) were objectively measured using quantitative immunofluorescence. Morphology was analyzed using light microscopy, phenotypic expression of the junctional protein zonula occludens (ZO‐1), and transmission electron microscopy (TEM).ResultsViability was maintained at all storage temperatures, except 24°C. The lowest number of dead cells were observed at 4°C (60% ± 18%; p = 0.001, compared to control). Cultures stored at 4°C best resembled the morphology of the unstored control cultures. The addition of sericin to the storage medium maintained viability, improved pigmentation, and increased levels of tyrosinase (141% ± 1%; p = 0.026) and premelanosomal protein‐17 (252% ± 8%; p = 0.014) following storage at 4°C.ConclusionsAfter seven days of storage, viability and morphology were best preserved at 4°C. Addition of the silk protein sericin to the storage medium maintained the characteristic HRPE morphology of the preserved cells, and improved pigmentation and phenotypic expression in cultured HRPE.
Mechanism of ‘Flap Closure’ after the inverted internal limiting membrane flap technique
Authors: Michalewska Z. , Bonińska K. , Michalewski J. , Nawrocki J. 
Published: September 2016

Purpose4 macular hole closure types are known: U‐type, V‐ type, irregular and flat open. After the inverted ILM flap technique some macular holes are covered only with a thin layer of the inverted ILM flap shortly after surgery (flap closure). The aim of this paper is to describe functional and anatomical results in eyes closed with ‘flap closure’.MethodsData of 190 eyes after vitrectomy with the inverted ILM flap technique were reviewed in order to spot eyes, in which the hole was open and covered only with a thin layer of the inverted ILM flap 1 week postoperatively. Swept Source OCT performed preoperatively and at 1 week, 1, 3, 6, and 12 months after surgery was anlyzed.ResultsFlap closure was noted in 50/190 eyes (26.3%) 1 week after surgery. Preoperatively, the minimum hole diameter was 544.04 μm and maximum diameter at the base was 1001.42 μm, in those eyes. Visual acuity improved from 0.91 logMAR to 0.54 logMAR 12 months after surgery. Final closure type of most eyes primarily closed with the inverted ILM flap technique was U‐type closure. Photoreceptor defects improved during the observation period (50 eyes – 1 week, 41 eyes – 1 month, 34 eyes – 3 months, 23 eyes – 6 months, 19 eyes – 12 months). Restoration of the external limiting membrane preceeded restoration of the photoreceptors. Retinal nerve fiber layer defects were noted in 16 eyes 1 month postoperatively. No new retinal nerve fiber layer defects were noted during the rest of follow‐up.ConclusionsMacular holes closed only with a thin layer of the inverted ILM flap preopeartively, improve their architecture up to 12 months after surgery. Visual acuity improvement was noted in those cases. ‘Flap closure’ is a new closure type, which probably enables closure of large macular holes, which would remain open without the use of the inverted ILM flap technique.
Variations in normative foveal morphology SD‐OCT data: A study of White, South Asian and Black ethnicities
Authors: Ctori I. , Huntjens B. 
Published: September 2016

PurposeFoveal morphology shows significant inter‐individual variation and ethnicity may play a role. We investigated variations in specific retinal layer thickness and foveal pit shape in three ethnic groups.MethodsWe recruited 226 healthy volunteers age 18–39 years (76 white, 80 South Asian and 70 black; male to female ratio 1:2 per ethnic group). Foveal thickness including inner retinal layer (IRL), outer nuclear layer (ONL), photoreceptor layer (PRL), retinal pigment epithelium (RPE), foveal width and foveal pit depth (FPD) were taken from Spectralis (Heidelberg, Germany) SD‐OCT scans. Retinal layer thickness measurements were taken from 0° to 3.8° eccentricity from the fovea. Two‐way ANCOVA evaluated the impact of ethnicity and gender confounders on foveal morphology parameters, while controlling for refractive error.ResultsWhite subjects had thicker central IRL (130 ± 21 μm) than South Asian (123 ± 16 μm) and blacks (116 ± 14 μm; F (2) = 12.4, p < 0.0005). This was also true for ONL (p < 0.0005) and PRL (p = 0.03), but not for RPE (p = 0.31). We report similar findings for thickness comparisons up to 3.8° retinal eccentricity. Foveal width was narrower in whites (2,226 ± 261 μm) compared to South Asian (2,417 ± 273 μm) and blacks (2,300 ± 223 μm; F (2) = 10.0, p < 0.0005). Ethnicity explained around 12% of the variance in IRL and foveal width, while gender played no significant role (p > 0.05). The depth of the foveal pit was significantly shallower in white (120 ± 25 μm) and South Asian (121 ± 18 μm) than blacks (129 ± 17 μm, F (2) = 4.8, p < 0.009), with no significant effect of gender (p = 0.39).ConclusionsThe overall foveal pit profile significantly varies with ethnicity. Our results indicate that ethnicity explains more of the variation in foveal morphology than gender, and should be taken into account when interpreting OCT scans.
Diabetic maculopathy screening in England; are we seeing too much?
Authors: Begum S. , Macgregor C. , Meredith P. , Cansfield J. , Meredith S. 
Published: September 2016

PurposeThe England screening service classification of diabetic retinopathy has strict, quality assured criteria to identify potential diabetic maculopathy termed ‘M1’. All new M1 cases identified by the screening service are referred to a hospital service. We aimed to evaluate the effectiveness of the England National Diabetic Eye Screening R1M1 classification of diabetic maculopathy as a criteria for secondary care referral in Portsmouth, UK.MethodsRetrospective audit of all patients referred to Portsmouth Hospitals NHS Trust with R1M1 pathology from April 2013 to January 2014. The total number of referrals received for this period was noted as well as the number of patients followed up in subsequent care pathways. Follow‐up data on those who remained under hospital care is presented for three years.ResultsA total of 306 diabetic patients were referred to Portsmouth Hospitals NHS Trust for R1M1 pathology over a 10 month period. At the first hospital appointment 135 (44%) had no fluid present on macular SD OCT and were either referred back to screening if the M1 features had resolved (65) or followed up with retinal images (70). 115 (38%) patients were considered to require further follow‐up in secondary care. Of those patients remaining in secondary care 70 remained in active follow up 3 years later.ConclusionsThese results would suggest that 44% of those with M1 features have no evidence of diabetic maculopathy on OCT at the initial hospital appointment and were discharged to community screening. Follow‐up for over three years in a secondary care setting is required by 23%. Secondary service could be better utilised by streamlining referrals either by refining the R1M1 classification or developing community based OCT service.
Improvement of diabetic macular edema after micropulse laser therapy
Authors: El Matri L. , Falfoul Y. , Chebbi Z. , Kortli M. , El Matri K. , Chebil A. 
Published: September 2016

PurposeMicroPulse technology (MP) is a new technique using a subthreshold laser micropulse. The desired effect is to reduce the laser damage to ocular tissue; its application in the macular area is very promising in order to treat diabetic macular edema (DME) with the less retinal damage.We present our 6 months experience with MicroPulse Laser Therapy in DME using a new multifunctional laser, the IRIDEX IQ577.MethodsWe used MP as first‐line therapy in cases of diffuse DME if central macular thickness (CMT) was <300 μm. However, if DME was diffuse and CMT was >400 μm, we began anti‐VEGF therapy to reduce CMT and improve vision as quickly as possible. We began with the laser set in traditional settings. We placed a test spot in a non‐edematous area of the retina and we increased the power up moving to a new area each time, until we note a thermal reaction (white burn). In the second step, we switch the laser to the micropulse setting and perform MP over the area of edema with a high‐density grid treatment.ResultsTen eyes of 8 patients were included. Mean age at diagnosis was 63.5 years. Best‐corrected visual acuity was 0.88 logmar (range 1.7–0.3) before treatment. After three months of MP, it improved to 0.67 logmar (range 1.4–0.2), p: 0.002. CMT was 367 μm, and improved to 316.5 μm (p: 0.14) at 1 month after treatment and to 291.2 μm at 3 months (p: 0.04). OCT detected early retinal reflectivity changes after treatment. All patients reported subjective improvement. No adverse events were observed during follow‐up.ConclusionsMP laser is an effective laser to treat DME. Moreover, the attractive safety profile of MP treatment allows clinicians to offer earlier treatment to prevent tissue damage and the development of visual disability.
Frequency doubling technology perimetry and retinal fiber layer correlation in type 2 diabetics without retinopathy
Authors: Aldaham S. , Martín‐Ridaura M.D.C. , Puell M.C. 
Published: September 2016

PurposeAlterations in visual field (VF) and retinal nerve fiber layer (RNFL) thickness were reported in diabetics. Little is known however about the extent to which VF and RNFL changes are affected and their correlations. The purpose was to assess the RNFL thickness and its correlation with VF parameters in type 2 diabetics without retinopathy with well controlled glucose level and good standard visual acuity.MethodsA total of 28 controls and 16 type 2 diabetics without retinopathy were recruited. VF was assessed with the frequency doubling technology (FDT) perimeter using the full threshold C‐20 program. The RNFL thickness was acquired by the optical coherence tomography 200 × 200 optic disc cube scanning protocol. Forward stepwise multiple linear regression analysis was applied to rule out the independent association of the RNFL thickness with the FDT parameters.ResultsCompared to the controls, the diabetics showed a trend of decreased RNFL thickness but was not significant, lower sensitivities for some VF locations, no difference in the mean deviation, and worse mean pattern standard deviation (PSD) (3.89 ± 0.36 vs. 3.47 ± 0.58 dB, p < 0.05). The RNFL thickness was significantly negatively correlated with PSD (r = −0.6, p < 0.05).ConclusionsApparent VF changes precede RNFL thickness thinning in type 2 diabetics without retinopathy. Also, the RNFL thickness shows a negative correlation with the PSD of the FDT parameter.
Quantification of green fluorescent protein expression in mouse retinal ganglion cells following intravitreal injection of recombinant adeno‐associated virus
Authors: Khatib T. , Osborne A. , Widdowson P. , Martin K. 
Published: September 2016

PurposeTo determine the transduction efficiency and spatial pattern of green fluorescent protein (GFP) expression in mouse retinal ganglion cells (RGCs) following intravitreal injection of recombinant adeno‐associated virus (rAAV2).Methods16 adult C57bL/6 mice received intravitreal injections of rAAV2‐CAG‐GFP at 3 different titres: 1 × 10E11, 1 × 10E12 or 1 × 10E13 genomic particles/ml. 2 μl of the virus was injected at each concentration. To determine the effect of volume on transduction efficiency, a subset of animals received 1 μl of the highest viral titre.Animals were sacrificed 21 days after injection. Retinal wholemounts were immunostained with Brn3a to identify RGCs and quantification carried out using imageJ software. The percentage of GFP positive RGCs was measured at each titre using Volocity software at 20× magnification. A further 20–25 images at 10× magnification were captured for each titre and merged using to reconstruct the entire wholemount to assess the spatial pattern of expression.ResultsRGC transduction rate increased with viral titre; 10% at 1 × 10E11, 53% and 1 × 10E12 and 64% at 1 × 10E13 genomic particles/ml. The volume injected did not appear to affect the transduction efficiency, with 64% of RGCs transduced at the highest titre using either 1 or 2 ul injection. GFP intensity also increased with viral titre with the spatial pattern of GFP expression more extensive at the highest titre. GFP expression at lower titres tended to localise around the injection site.ConclusionsGFP transduction efficiency of RGCs can be quantified efficiently using Volocity software. We have demonstrated an increase in GFP expression and spread at higher viral titres with similar transduction efficiency at a lower volume.
Mechanisms behind the protein aggregation‐related inflammasome activation in RPE cells
Authors: Kauppinen A. , Piippo N. , Korhonen E. , Hytti M. , Kinnunen K. , Kaarniranta K. 
Published: September 2016

PurposeInflammasomes are intracellular protein complexes whose activation results in the caspase‐1‐mediated release of pro‐inflammatory cytokines IL‐1β and IL‐18. We and others have shown that activation of NLRP3 inflammasome is associated with the pathogenesis of age‐related macular degeneration (AMD). Declined proteasomal degradation with concurrent autophagy inhibition is among the risk factors activating the NLRP3 receptor in retinal pigment epithelial (RPE) cells. NLRP3 is known to have various activation mechanisms and in the present study, we have analyzed which of them contribute to the inflammasome activation when protein degradation systems in RPE cells fail.MethodsInflammasome activation was induced in human ARPE‐19 cells by the proteasome inhibitor MG‐132 and the lysosome neutralizer Bafilomycin A. Extracellular ATP was measured, and its receptors were inhibited using a P2X7 inhibitor. Potassium efflux was inhibited using high extracellular ion concentration, and glyburide was added to block the ATP‐mediated potassium efflux. APDC (ammonium pyrrolidine dithiocarbamate) and NAC (N‐acetylcysteine) were used to reduce oxidative stress.ResultsDespite increased extracellular ATP level, the inhibition of P2X7 receptors did not reduce the secretion of IL‐1β. Neither potassium efflux nor cathepsin B contributed to the inflammasome activation in our model, but ROS inhibitors alleviated the IL‐1β production.ConclusionsOur results suggest that oxidative stress plays a role in the inflammasome activation in RPE cells upon declined intracellular clearance.
Incidence of retinal vein occlusions (RVO) in patients treated with oral anticoagulants or antiplatelet drugs for cardioembolic or atherothrombotic prevention
Authors: Fruschelli M. , Fazio S. , Capozzoli M. , Chimenti G. , Hadjistilianou T. , Sicuranza A. , Aprile L. , Puccetti L. 
Published: September 2016

PurposeIt is still a matter of debate whether anticoagulant or antiplatelet therapy are useful for the prevention of retinal vein occlusions. In some cases, patients who are already under antiplatelet or anticoagulant therapy still develop retinal venous diseases. We analyzed the prevalence of RVO in patients treated yet with warfarin or aspirin for other clinical indications.Methods64 patients (30 CRVO and 34 BRVO) treated with warfarin for atrial fibrillation (n = 11) or aspirin for carotid stenosis (n = 53) were observed. Multivariate analysis was employed to detect any putative relation among treatments and CRVO or BRVO.ResultsThe whole cohort analysis showed that aspirin was less effective than warfarin for prevention of RVO (H.R. 2.4, 95% C.I. 1.9–3.2 p < 0.01); 9 BRVO and 2 CRVO were in patients treated with warfarin whereas 25 BRVO and 28 CRVO in aspirin treated subjects. The confirmation test showed an H.R. of 2.1 (1.6–3.1 95% C.I.) p < 0.01, for the association between aspirin treatment and CRVO.ConclusionsSuch retrospective data indicate that aspirin could be less effective in RVO and particularly CRVO prevention with respect to anticoagulants. Planned large prospective observational studies are needed to study the efficacy of such treatments in RVO prevention and treatment. Our data could fit well with the previous observation that specific pro‐coagulative state as suggested by increased thrombin generation is a pattern of CRVO with respect to BRVO.
Increased intraocular pressure causes deficiency in the level of ELAVL1/HuR cytoplasmic fraction in the retina
Authors: Smedowski A. , Trzeciecka A. , Podracka L. , Pietrucha‐Dutczak M. , Lewin‐Kowalik J. , Akhtar S. , Kaarniranta K. , Amadio M. 
Published: September 2016

PurposeTo evaluate impact of raised intraocular pressure on RNA binding protein ELAVL1/HuR expression in retina.MethodsIn order to induce glaucomatous damage, intraocular pressure was increased unilaterally using modified rat bead model and maintained for up to 8 weeks. Fellow eye was used as a healthy control. Animals were sacrificed, retina and optic nerves were collected and processed for western blot (WB) analysis or for immunostainings.ResultsGlaucomatous damage was confirmed in electron microscopy by the presence of axonal damage, myelin sheat dezintegration and glial cells proliferation within the optic nerve. Eight weeks glaucoma induced up to 36% loss of Retinal Ganglion Cells (RGCs) in the retina. In fractionated WB analysis of retinal homogenates, the level of active, cytoplasmic fraction of HuR was decreased approximately 3‐times when compared with healthy tissue (p < 0.05). Additionally, the cytoplasmic levels of cell cycle regulatory proteins (Hsp70, p53), whose expression is regulated by HuR, were also decreased. Stereological analysis of retinas revealed decrease in the number of double‐stained RGCs (positive for β3tubulin + HuR) below the number of total β3tubulin positive RGCs (1,960 ± 885 cells/mm2 vs. 2,136 ± 689 cells/mm2) what means that some of them lost visible HuR expression. Immunostaining of retinal and optic nerves cross sections showed decreased expression of HuR within RGCs and increased expression within optic nerve glia in glaucoma samples.ConclusionsIncreased intraocular pressure results in defect of active fraction of RNA binding HuR protein within retina and specifically within RGCs. This defect is linked with decreased expression of HuR‐dependent regulatory proteins (Hsp70, p53). This might be mechanism contributing to the development of glaucomatous degeneration.
Infectious keratitis after penetrating keratoplasty: predisposing risk factors and prognosis
Authors: Hassairi A. , Limaiem R. , Ben Mrad A. , Rayhan H. , Turki R. , El Matri L. 
Published: September 2016

PurposeTo investigate prevalence, predisposing risk factors and prognosis of graft survival in patients who developed infectious keratitis following penetrating keratoplasty (PK).Methodswe undertook a retrospective analysis of 16 patients hospitalized at the Institute of Ophthalmology of Tunis for the occurrence of infectious keratitis following PK over an seven‐year period (From March 2009 to March 2016). We excluded all herpetic keratitis secondary to PK. Efficacy of treatment was evaluated by anatomical (clarity of graft) and visual recovery.ResultsPrincipal indications for PK were corneal opacity (secondary to infectious keratitis in 2 cases and to trachoma in 2 cases), therapeutic penetrating keratoplasty for corneal perforation in 5 cases, keratoconus in 3 cases, pseudophakic bullous keratopathy in one case and penetrating keratoplasty in children in 3 cases. Principal predisposing risk factors were suture‐related problems (56.25%) followed by topical corticotherapy (43.75%) and persistant epithelial defect in (43.75%). The microbiological examinations were positive in 70.58% of the cases: bacillus Gram +: 66.66%, Bacillus Gram Négatif: 8.33%, amoeba: 8.33% of the cases. We noted two cases of polymicrobial infection. Four patients underwent PK. The infection was solved in 100% of the cases but with opacities of the transplant in 75% and a severe limitation of the visual acuity.ConclusionsThe development of infectious keratitis after PK is a serious complication that is associated with a high incidence of graft failure and poor visual outcome. Preventive measures are essential and include a regular follow‐up and education of the operated patients.