bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro studies on the mechanism of action of VEGF and its inhibitors on blood‐retina barrier
Authors: DEISSLER H , LANG G
Published: August 2012

Purpose VEGF‐induced permeability of immortalized endothelial cells of the bovine retina (iBREC) can be completely restored by the VEGF‐binding Fab‐fragment ranibizumab, but expression of other growth factors like bFGF, IGF‐1 or PLGF is also elevated in diabetic macular edema (DME). Therefore, we investigated whether combination of these growth factors enhance or diminish the long‐term effect of VEGF and whether combined effects can be restored by VEGF‐inhibition alone. We also studied potential uptake and accumulation of ranibizumab or the humanized VEGF‐binding antibody bevacizumab.

Methods Measured transendothelial resistance (TER) of iBREC (+/‐ growth factors or inhibitors) showed effects on permeability, indicated also by Western blot‐determined tight junction protein Claudin‐1. Uptake of VEGF inhibitors by iBREC was visualised by immunofluorescence staining and Western blot analyses.

Results VEGF decreased TER and Claudin‐1 in a concentration dependent manner whereas bFGF, IGF‐1 or PLGF as single agent did not influence these processes during treatment for 2 days. In contrast to PLGF, bFGF and IGF‐1 maintained the effect of VEGF especially at low VEGF concentrations. Reduction of TER or Claudin‐1 induced by combination of all growth factors was completely restored by addition of ranibizumab. Both VEGF inhibitors were internalised but bevacizumab accumulated further. Ranibizumab was found in the membrane/organelle fraction, whereas bevacizumab associated with the cytoskeleton. Both inhibitors did not disturb the barrier of iBREC.

Conclusion VEGF is mainly responsible for disrupting the barrier function of REC. This supports VEGF targeting as a therapeutic concept. Independent research grant by Novartis Pharma, Germany
Role of retinal glial cells in pathogenesis of macular oedema
Authors: YANDIEV Y , BRINGMANN A , WIEDEMANN P
Published: August 2012

Purpose Macular edema is a complex nonspecific reaction that results in intraretinal fluid accumulation and leads to a decrease of retinal transparency and visual impairment. Virtually all retinal disorders associated with ischemia, inflammation and/or mechanical traction may be accompanied by the development of macular edema. The pathogenic mechanisms underlying the development of macular edema are largely unresolved. Most studies favor vasogenic edema as key mechanism in the development of macular edema. However there are indications that a swelling of retinal Müller cells may also contribute to the development of macular edema.

Methods Immunohistochemical staining as well as recording of Müller cells behavior was investigated under normal conditions, under osmotic stress and under different pathological processes, e.g., retinal ischemia, ocular inflammation, and diabetes.

Results The Müller cells are responsible for the maintenance of the retinal homeostasis including intraretinal osmolyte and water homeostasis through coupling of transglial water fluxes (via aquaporins) to potassium currents clearance. Functional alterations of Müller cells in course of ischemia and/or inflammation contribute to the downregulation of potassium conductance and intracellular overload of potassium ions. This results in osmotically driven water movements from the blood and vitreous into the glial cells and causes neuronal hyperexcitability and glial cell

Conclusion An impairment of ion and water movements through Müller cells (in addition to vascular leakage) may contribute to the development of macular edema. A better understanding of the mechanisms of cellular ion and water homeostasis will facilitate the development of efficient edema‐resolving drugs.
Combination of ranibizumab and laser photocoagulation in CRVO
Authors: WIEDEMANN P , REHAK M
Published: August 2012

Purpose In a model of CRVO upregulation of VEGF was strongest in the ischemic areas. Therefore initiated a proof of concept study to evaluate the efficacy of intraocular ranibizumab injections combined with laser photocoagulation of the non perfused areas in patients with CRVO.

Methods 22 patients with areas of non‐perfusion were randomized into two groups. In the treatment arm patients received the ranibizumab injections with additional selective laser photocoagulation. The controls were treated with ranibizumab only. All patients received an upload and were re‐injected in a PRN regimen. The results at month 6 were evaluated. The change in BCVA compared with baseline as well as the amount of ranibizumab injections and the percentage of patients progressing to neovascularization ( retina and/or anterior segment) were analyzed in the both arms.

Results BCVA increased at month 6 compared with baseline in the treatment arm from 61.6±12.7 to 68.9±13.7 ETDRS letters and in the control arm from 59.25±10.9 to 64.1±16.5 letters. One control patient developed retinal neovascularisation and required panretinal aser photocoagulation. Due to the small number of patients the differences between experimental and control arm are not statistically significant. The sample size calculation showed, that 100 patients are required to achieve the statistical power of 90%.

Conclusion The preliminary results of the study showed a positive effect of the additional selective laser photocoagulation in patients with CRVO. The laser treatment seems to lead to faster and substantial resolution of the macular edema. A multicenter trial is currently prepared to confirm the results of this proof of concept study.
Vasomotor reaction of retinal arterioles in hypoxic and ischemic conditions
Authors: POURNARAS CJ
Published: August 2012

Purpose Retinal blood flow is autoregulated by the adaptation of the vascular tone of resistance vessels (arterioles, capillaries) to changes in the perfusion pressure (PP) or metabolic needs of the tissue. The purpose of this study was to evaluate the disturbance of arteriolar reactivity, and thus of blood flow regulation, during the evolution of ischemic retinal microangiopathies.

Methods Much of our basic knowledge of retinal arteriolar reactivity is based on data obtained from animal experiments through the use of invasive techniques. However, a variety of non‐invasive techniques has been applied to the human eye for the investigation of retinal hemo‐dynamics and, more specifically, the reactivity of the retinal arterioles in response to a number of physiologic and pharmacologic stimuli, under normal, hypoxic and ischemic conditions.

Results In patients with non‐proliferative diabetic retinopathy (DR), isocapnic hypoxia induces a significant increase in Vleuk in the perifoveal circulation, whereas in patients with proliferative DR, the diameter of the retinal vessels remains unchanged, indicating that blood flow regulation in response to a hypoxic challenge is blunted,consequent to the hypoxic retinal conditions. In those patients a hyperoxia‐induced blunted vasoconstriction of the retinal arterioles is also observed. The ability of the retinal arterioles to respond to changes in ocular PP is altered in diabetes, while the response of retinal vessels to diffuse luminance flicker is blunted, particularly in patients suffering from insulin‐dependent diabetes.

Conclusion During the evolution of retinal ischemic microangiopathies, impairment of various mechanisms of retinal arteriolar reactivity leads to disturbed retinal blood flow regulation.
Anatomical location of polypoidal choroidal vasculopathy lesions inferred from simultaneous ICGA‐OCT
Authors: KANG SW , JH KIM , HA HS
Published: August 2012

Purpose To identify the spatial location of polypoidal choroidal vasculopathy (PCV) lesions including branching vascular network (BVN) and late geographic hyperfluorescence (LGH).

Methods This retrospective study involved 15 eyes (15 subjects) affected by active PCV. Utilizing innate software for simultaneous indocyanine green angiography (ICGA) and optical coherence tomography (OCT), we identified the corresponding tomographic locations of BVN and LGH on ICGA.

Results LGH was noted in 9 eyes, and the extent of LGH was the same (5 eyes) as or larger (4 eyes) than the extent of BVN. The extent of ‘double layer sign’ on OCT coincided exactly with the extent of LGH on ICGA. Image analysis revealed that larger vessels of BVN located not in‐between retinal pigment epithelium and Bruch’s membrane but within choroidal layer.

Conclusion This study indicates that, at least, a part of BVN locates within choroidal layer. And the tomographic location of the lesion corresponding to LGH lies above Bruch’s membrane. The origin of LGH would be fluorescein staining of the lesion above Bruch’ membrane, possibly due to exudation from BVN.
Keratoconus and keratectasia
Authors: COLIN J
Published: August 2012

Abstract not provided
Long‐term results of deep anterior lamellar keratoplasty in patients with keratoconus
Authors: FOURNIE P , TOUBOUL D , ARNE JL , COLIN J , MALECAZE F
Published: August 2012

Purpose Long‐term endothelial cell density changes and visual and refractive outcomes after descemetic (d) and predescemetic (pd) deep anterior lamellar keratoplasty (DALK) using the big‐bubble technique in eyes with keratoconus.

Methods Retrospective, consecutive, non‐comparative, case series analysis of 95 eyes that have undergone DALK for keratoconus using the big‐bubble technique with at least 1 year of follow‐up. Big‐bubble was achieved in 74 (77.9%) eyes (dDALK), whereas 21 (22.1%) eyes underwent manual lamellar dissection (pdDALK) because of failed big‐bubble.

Results Descemet ruptures occurred in 13 of 95 cases (13.7%). Five ruptures (5.3%) were converted to penetrating keratoplasty. Mean length of follow‐up was 5.3 years (range, 1‐8 years). Postoperative best spectacle‐corrected visual acuity was significantly better in dDALK group than in pdDALK group at years 1 and 2. But, at the final examinations, there was no significant difference between the study groups (0.25 ± 0.22 logarithm of the minimum angle of resolution in dDALK group and 0.33 ± 0.15 logarithm of the minimum angle of resolution in pdDALK group; p = 0.12). The 2 groups were comparable regarding astigmatism and spherical equivalent refractive error throughout the follow‐up period. Mean endothelial cell loss was 22.5 ± 17.9% at last follow‐up with most of the loss occurring in the first year (8.7% ± 5.6%). Stromal graft rejection episodes occurred in 3 eyes (3.2%), which resolved with appropriate therapy.

Conclusion DALK using the big‐bubble technique is effective in patients with keratoconus. In DALK, manual lamellar dissection is a reasonable alternative when big‐bubble separation of the Descemet membrane is not achieved.
Visual and refractive outcomes of intracorneal ring segments in the treatment of keratoconus: the RETICS multicentrical study
Authors: VEGA‐ESTRADA A , ALIO JL , MICHAEL R , BARRAQUER RI
Published: August 2012

Purpose Analyze the outcomes of intracorneal ring segment (ICRS) implantation for the treatment of Keratoconus based on preoperative visual impairment. Design: Multicenter, retrospective, nonrandomized study.

Methods 611 eyes of 361 keratoconic patients were evaluated. Subjects were classified according to their preoperative corrected distance visual acuity (CDVA) into five different groups: Grade I, CDVA of 0.90 or better, Grade II, CDVA equal or better than 0.60 and worse than 0.90, Grade III, CDVA equal or better than 0.40 and worse than 0.60, Grade IV CDVA equal or better than 0.20 and worse than 0.40 and Grade Plus, CDVA worse than 0.20. Success and failure indexes were defined based on visual, refractive, corneal topographic and aberrometric data and evaluated in each group six months after ICRS implantation.

Results Significant improvement after the procedure was observed regarding uncorrected distance visual acuity in all grades (p<0.05). CDVA significantly decrease in Grade I (p<0.01), but significantly increases in all other grades (p<0.05). 37.9% of patients with preoperative CDVA 0.6 or better gained 1 or more lines of CDVA, while 82.8% of patients with preoperative CDVA 0.4 or worse gained 1 or more lines of CDVA (p<0.01). Spherical equivalent and keratometry readings showed a significant reduction in all Grades (p≤0.02). Corneal higher order aberrations did not change after the procedure (p≥0.05).

Conclusion Based on preoperative visual impairment, ICRS implantation provides significantly better results in patients with a severe form of the disease. A notably lost of CDVA lines can be expected in patients with a milder form of Keratoconus.
Keratocyte density after microkeratome LASIK versus femtosecond laser‐assisted LASIK
Authors: CANADAS SUAREZ PILAR , HERNANDEZ‐VERDEJO JL , DE BENITO LLOPIS L , DRAKE P , TEUS MA
Published: August 2012

Purpose to compare the keratocyte density after microkeratome LASIK (MK‐LASIK) and femtosecond‐laser assisted LASIK (FS‐LASIK)

Methods We performed a prospective study of myopic patients that underwent MK‐LASIK or FS‐LASIK. We measured keratocyte density 3 and 15 months, and 3‐5 years after the surgery using confocal microscopy

Results we included 31 eyes in LASIK (FS‐LASIK) and 30 eyes MK‐LASIK, we detected an initial increase in the keratocyte population of the whole cornea, due to an increase in the stromal bed and mid and posterior stromal layers, followed by a normalisation of those deeper layers, and a decrease of the cell density in the stromal flap and stromal bed 3‐5 years postoperatively. The average cell density throughout the cornea was not decreased compared to controls.

Conclusion : we found a reorganization of keratocytes in the cornea up to 5 years after LASIK, with a decrease in the stromal flap and bed, but maintaining normal average cell densities, and with no significant differences between MK and FS‐LASIK.
Evaluation of intraocular pressure according to corneal thickness before and after Excimer laser corneal ablation for myopia
Authors: HAMED AZZAM S , BRISCOE D , TOMKINS O , SHEHADEH M , GARZOZI H
Published: August 2012

Purpose Intraocular pressure is affected by corneal thickness and biomechanics. Following ablative corneal refractive surgery, corneal structural changes occur. Our aim in this study was to determine the relation between the mean central corneal thickness and the change in intraocular pressure measurements following various corneal ablation techniques, using different measurement methods.

Methods This is a prospective, nonrandomized study.200 myopic eyes undergoing laser in situ keratomileusis or photorefractive keratectomy were enrolled. Corneal parameters examined included, full ocular examination, measurement of central corneal thickness, corneal topography, corneal curvature and ocular refractivity. Intraocular pressure measurements were obtained using three different instruments: Non Contact Tonometer, Goldmann Applanation Tonometer and TonoPen XL (TonoPen‐Central, and TonoPen‐Peripheral). All measurements were performed preoperatively and 4 months postoperatively. differences in inter‐device intraocular pressure measurements were done using ANOVA test.

Results Postoperative intraocular pressure was significantly lower than preoperative values, with all instruments (p value <0.001, Student's t‐test). The postoperative intraocular pressure decrease was smallest using the Tonopen‐XL compared to the Goldmann applanation tonometer and Non‐contact tonometer (p value <0.001,ANOVA).

Conclusion Intraocular pressure readings are significantly reduced following corneal ablation surgery. We determined in our myopic patient cohort that the TonoPen XL intraocular pressure measurement method is the least affected following photorefractive keratectomy and laser in situ keratomileusis as compared to other techniques.
Parapapillary atrophy: histological gamma zone and delta zone
Authors: JONAS JB , JONAS S , JONAS R , HOLBACH L , DAI Y , SUN X , PANDA‐JONAS S
Published: August 2012

Purpose To examine histomorphometrically the parapapillary region in human eyes

Methods The histomorphometric study included 65 human globes (axial length:21‐37mm). On anterior‐posterior histological sections, we measured the distance Bruch´s membrane end (BME)‐optic nerve margin (“Gamma zone”), BME‐retinal pigment epithelium (RPE) (“Beta zone”), BME‐beginning of non‐occluded choriocapillaris, and BME‐beginning of photoreceptor layer. “Delta zone” was defined as part of gamma zone in which blood vessels of at least 50µm diameter were not present over a length of >300µm.

Results Beta zone (mean length:0.34±0.52mm) was significantly (P=0.046) larger in the glaucoma group than in the non‐glaucomatous group. It was not significantly (P=0.28) associated with axial length. Beta zone was significantly (P=0.03) larger than the region with occluded choriocapillaris. Gamma zone (mean length:0.63±1.15mm) was associated with axial length (P<0.001;r2=0.72) with an increase starting at an axial length of 26.5mm. It was not significantly (P=0.24) associated with glaucomatous optic neuropathy. Delta zone (present only in eyes with axial length of ≥27mm) was associated with axial length (P=0.04) but not with glaucoma (P=0.18).

Conclusion Parapapillary gamma zone was related with axial globe elongation and was independent of glaucoma. Beta zone (Bruch´s membrane without RPE) was correlated with glaucoma but not with globe elongation. Since the region with occluded choriocapillaris was smaller than beta zone, complete loss of RPE may have occurred before complete choriocapillaris closure. Delta zone was present only in highly axially elongated globes.
Therapeutic options for narrow angle glaucoma
Authors: VAN DE VEIRE S
Published: August 2012

Purpose To explain into detail the different therapeutic options present today for the treatment of narrow angles with and without glaucoma. Since not much is understood yet from narrow angle glaucoma; for instance why do some patients develop acute glaucoma and others don't?

Methods Patients files of patients with narrow angles (classified by Visante OCT readings with an angle depth of less than 10°) were retrospectively investigated and subdivided into different groups based on the treatment they received. The first group received a bilateral Argon laser iridoplasty followed a bilateral yag iridotomy; whereas the second group of patients received a primary phacoemulsification. Primary outcome was the intraocular pressure, secondary outcome the effect on the Visante OCT and thereby the influence of the angle structure on progression of glaucoma.

Results Both methods same to be effective in lowering the intraocular pressure. Of great importance is the selection of patients. Patients with a huge lens rise will obviously benefit more from a phacoemulsification, whereas hypermetropic patients will have a sufficient effect from the Argon‐Yag combination. Complications, repeatability, effectiveness of the therapies will be further compared in a prospective trial.

Conclusion Both methods same to be effective in lowering the intraocular pressure. Randomized, prospective clinical trials are further necessary to solve this horrific type of narrow angle glaucoma.
When should we retreat choroidal melanomas?
Authors: MASCHI C , GASTAUD P , GAL J , CAUJOLLE JP
Published: August 2012

Purpose Early detection of choroidal melanomas' relapse after conservative treatment is a challenge. Ocular echography is the main exam for the follow up of tumoral thickness, but are all the growths observed after treatment reccurences? We decided to study the regression pattern of uveal melanomas after proton beam therapy to look for an association with local recurrences.

Methods Our study is a retrospective study on all the patients treated by proton beam therapy at the Cyclotron of Nice between june 1991 and july 2010. Our inclusion criterias were a minimum of two echographic eight measurments after treatment and a follow up of a minimum of 6 months, exams were made by the same specialist(JPC).

Results Over the 1155 patients treated, 779 encountered the inclusion criterias. The mean decrease is 8% at 6 months, 20% at 12 months and 35% at 24 months. we observed that 70% of the tumors are stable at 6 months, 50% at 12 months and only 30% at 24 months. An increase of more than 15% is encoutered in 10% of the patients at 6 months, 5 and 2,5% at 12 and 24 months. At 6 and 12 months, tumors which increase is bigger than 15% show no differences for local control. At 24 months,there is a significative difference for local control if the tumor increases(p=0,0003).

Conclusion Analysis of regression pattern allows us to observe that an increase of tumoral thickness is quite usual and isn't statistically linked to local control failure if observed before 12 months. Confirmation of tumor growth is then necessary before an enucleation or a second radiotherapy. After 24 months, we found an association between recurrences and tumor growth and we need new exam to quickly confirm the diagnosis and start treatment.
Second course of proton beam therapy for recurrent uveal melanoma
Authors: PAOLI V , DELAS J , CAUJOLLE JP
Published: August 2012

Purpose To evaluate the outcomes of patients with recurrent uveal melanoma, treated by a second course of fractionated proton beam therapy (PBT) or by enucleation

Methods Tumor recurrence was documented in 54 patients treated with PBT for uveal melanoma. Of these patients, 26 received a second course of PBT and 22 underwent enucleation. The mean patient age was 60,4 years (range, 27–85 years). Among patients with recurrence, the mean followup time was 5,8 years (range, 6 months–16,4 years). The mean visual acuity was 4,5/10 initially. All patients received 60 cobalt Gray equivalent for both courses. 24 recurrences occurred at the margin. The tumor regrowth was within the irradiated area in 17 patients (global recurrence), through the sclera in 4 patients (extra sclera extension), and completely outside the irradiated area in 9 patients.

Results The 5‐year cumulative rate of local recurrence after the second treatment was 7,69 % (2 patients among 26 reirradiation). There had 5 enucleations (19,3%) among 26 reirradiations. A third of reirradiated patients maintained useful vision after a second course of PBT : 39% had 20/200 vision or better after the second treatment. The Kaplan‐Meier overall survival rate is better with Proton Beam Therapy (PBT) VS Enucleation ( p<0,02)

Conclusion A second course of PBRT for recurrent uveal melanoma was associated with a relatively good probability of local control and a low enucleation rate. This retrospective analysis suggests that survival in reirradiated patients is not compromised by administration of a second course of PBT for recurrent uveal melanoma.
Uveal melanoma among Finnish children and adolescents
Authors: ALJAMAL R , KIVELÄ T
Published: August 2012

Purpose To report uveal melanoma (UM) before the age of 25 years in Finland, a high incidence region for this cancer.

Methods A population‐based study identified 24 patients (0.3%), aged between 13 and 24 years at diagnosis, treated in our hospital in 1963‐2006. They were divided in two groups, the first consisted of 11 patients (9 females, 2 males) enucleated before 1997. The second was treated by irradiation after 1991, consisting of 11 patients (9 females, 2 males). Two other patients underwent local resection (male and female).

Results Tumour height was 4‐11 mm (mean, 7) in the first and 4.4‐13.7 mm (mean, 8.5) in the second group and largest basal diameter ranged from 5‐16 mm (mean, 10) and 2.5‐ 21 mm (mean, 15), respectively. Four patients died, 3 of UM (after 4, 12 and 21 years). All were female with spindle tumours. In the second group, 2 females died of UM (after 3 and 4 years).

Conclusion UM is rarely seen among young children and adolescents. In this small series, females outnumbered males.
A randomized multicentric phase III ongoing study of adjuvant fotemustine versus observation in high risk uveal melanoma patients (FOTEADJ)
Authors: PIPERNO‐NEUMANN S
Published: August 2012

Purpose International guidelines recommend 6 monthly liver US after the local treatment of uveal melanoma (UM), with a constant 20% rate of metastasis, and no impact on the outcome (survival or R0 liver surgery). Clinical risk factors for metastasis include age, largest tumor diameter(LTD),ciliary body involvement, retinal detachment, extra‐scleral extension, epithelioid cell type. More recently, genetic alterations of chromosome 3 and 8 have been shown to be highly predictive of a poor prognosis.

Methods We designed a multicentric phase III study with adjuvant Fotemustine versus observation in 302 UM patients with high‐risk of recurrence, defined by clinical criteria: LTD≥15 mm with extra scleral extension or retinal detachment or LTD≥18 mm; or genomic high risk signature(a‐CGH, NimbleGen 72K microarray) monosomy 3 or partial deletion of 3p associated with 8q gain. The primary objective is to increase the 5‐year Metastasis Free Survival from 50 to 70% (5% type I error rate,95 % power).Secondary objectives are overall survival,safety, quality of life.

Results Main inclusion criteria: age ≥18 years, ECOG PS ≤2, no prior chemotherapy or history of invasive cancer,and written informed consent. The genomic analysis is performed by FNA biopsies before the conservative treatment for small UM or after enucleation for large tumors. Schedule: Fotemustine 100 mg/m2, 1 hour IV infusion D1D8D15(induction cycle);5 week rest period; 5 maintenance cycles 100 mg/m2 1 hour IV infusion D1 D21 Follow up period: 3 years (LFTs/3 months, liver MRI or CT/6 months, whole body CT/12 months)

Conclusion June 2009‐Jan 2012:70 patients were included in 4 participating centres, extension to other countries is underway.
Quantification of axonal loss in pseudotumor cerebri syndrome using macular thickness measurements with frequency domain‐OCT
Authors: MONTEIRO M , AFONSO C
Published: August 2012

Purpose To evaluate the ability of fourier domain‐optical coherence tomography (FD‐OCT)‐measured macular thickness parameters to differentiate between eyes with chronic papilledema from pseudotumor cerebri (PTC) and healthy eyes and its relationship with visual field (VF) loss on standard automated perimetry (SAP).

Methods Fifty‐five eyes from 30 patients with PTC syndrome and 70 eyes from 35 normal controls underwent FD‐OCT (3D OCT‐1000, Topcon) scanning and ophthalmic evaluation including SAP using Humphrey perimetry. All patients had been submitted to previous treatment with clinically resolved papilledema and stable VF for at least 6 months. Macular and peripapillary RNFL thickness measurements were determined. Comparisons were made using Generalized Estimated Equations. Correlations between OCT and VF measurements were also verified.

Results All macular and most RNFL thickness measurements were significantly reduced in eyes with resolved papilledema from PTC syndrome compared to normal controls. Although both OCT‐measured macular and RNFL thickness measurements correlated with visual loss on SAP, correlation coefficients were greater for former.

Conclusion Eyes with chronic papilledema show significant macular thinning which is correlated with the severity of VF loss. Macular thickness measurements could potentially estimate the amount of ganglion cell loss during follow‐up of patients with pseudotumor cerebri syndrome.
Triamcinolone regulated apopto‐phagocytic gene expression patterns in the clearance of dying cells in the retina
Authors: PETROVSKI G , ALBERT R , KRISTOF E , ZAHUCZKY G , BERTA A , FESUS L
Published: August 2012

Purpose The clearance of dying cells in the retina has known relevance to development of age‐related macular degeneration (AMD). We aimed to investigate the gene expression patterns present during such a clearance process and the effect of triamcinolone (TC) treatment on them.

Methods Primary human retinal pigment epithelium (hRPE) and ARPE‐19 cells were induced to undergo cell death by loss of extracellular matrix attachment (anoikis). Phagocytic clearance assays of the engulfment of anoikic cells by human monocyte‐derived macrophages (HMDMs) were performed in the presence or absence of TC. Phagocytosis was quantified using a standard double‐staining method on flow cytometry. TaqMan low‐density array determining the gene expression of known markers of phagocytosis was carried out in HMDMs engulfing anoikic cells. Loss‐of‐function studies using siRNA were also performed on selected apopto‐phagocytic genes.

Results The glucocorticoid TC had a profound phagocytosis‐enhancing effect on HMDMs engulfing anoikic hRPE or ARPE‐19 cells, causing a selective upregulation of the Mer tyrosine kinase (MERTK) receptor, while decreasing the expression of the AXL receptor tyrosine kinase and THSB‐1 (phagocytosis bridging molecule). Similar expression patterns were also observed in the anoikic cells. The key role of the MERTK could be demonstrated in HMDMs engulfing the dying cells using gene silencing as well as blocking antibodies.

Conclusion Specific agonists of the tyrosine kinase receptors may have a potential role as phagocytosis enhancers in the retina and serve as future targets for AMD therapy.
Assessment of the retinal pigment epithelial functions‐ modelling approach
Authors: HYTTINEN J , VAINIO I , KHAMIDAKH A , JUUTI‐UUSITALO K , LUUKKANEN H , SKOTTMAN H , NYMARK S
Published: August 2012

Purpose Our purpose is to construct mathematical models of functions of retinal pigment epithelium (RPE). Here we show the development and results of two models: 1) a compartmental model of Ca2+ dynamics 2) finite element model of epithelial transport and trans‐epithelial resistance.

Methods A model of Ca2+ dynamics of APRE‐19 cells based on an experimental data and literature was constructed. Ca+2 dynamics of APRE‐19 cells were recorded using fluorescent microscope after mechanical stimulation. Various Ca+2 functional conditions were tested. The computational model constructed (Matlab SimBiology ) comprises over 40 cell function parameters and twelve variables ranging from stretch‐sensitive ion channels to ryanodine receptor dynamics and sarco/endoplasmic reticulum ATPases. Further, a model of RPE epithelia barrier was developed based on finite element modelling (FEM) of the epithelia and trans‐epithelial resistance simulating the spatial distribution of epithelial properties originating of the tight junction distribution on epithelia.

Results The Ca+2 kinetics model of RPE was able to reproduce the Ca+2 dynamics of APRE cells with high accuracy with above 0.97 cross‐correlation. Further, including stretch‐sensitive ion channels explained the Ca+2 dynamics of the cells close to the mechanically stimulated cell. The epithelial model showed that epithelial inhomogeneity may play a crucial role in epithelial tightness and even very small cellular changes produce large variation on the measures of the epithelial properties.

Conclusion The models constructed provide new insight of the functions of the RPE with applications from drug transport studies to assessment of the functionality of stem cell derived RPE.
CD34 marks angiogenic tip cells in human vascular endothelial cell cultures: a new model to study mechanisms of ocular angiogenesis
Authors: SCHLINGEMANN RO , SIEMERINK MJ , GRIFFIOEN AW , KLAASSEN I , VAN NOORDEN CJF
Published: August 2012

Purpose The functional shift of quiescent endothelial cells into tip cells that migrate and stalk cells that proliferate is a key event during sprouting angiogenesis. Unfortunately, a model of tip cells in vascular endothelial cell cultures is lacking.

Methods We employed the sialomucin CD34 to isolate a small subset of elongated endothelial cells with filopodia from endothelial cell cultures and tested if these cells had properties similar to tip cells in vivo at the functional and molecular level.

Results As predicted by our hypothesis, CD34+ endothelial cells had low proliferation activity. The CD34+ phenotype was upregulated by VEGF‐A and downregulated by TNF‐alpha and DLL4, three mechanisms known to regulate the tip cell phenotype in vivo. Real‐time qPCR and microarray data analysis of the CD34+ cells identified increased expression of all known genes previously associated with tip cells in vivo. Genome‐wide mRNA profiling analysis of CD34+ cells demonstrated enrichment for biological functions related to angiogenesis and migration, whereas CD34‐negative cells were enriched for functions related to proliferation

Conclusion Our findings suggest that cells with virtually all known properties of tip cells are present in vascular endothelial cell cultures, and that they can be isolated based on expression of CD34. In addition, we characterized the transcriptome of these cells and identified many novel genes with potential significance for angiogenesis. This novel strategy may open alternative avenues of research that may help to understand the molecular processes and functions in angiogenesis in general and of the specialized endothelial tip cell in particular.
VEGF Trap‐Eye: features of the molecule
Authors: TADAYONI R
Published: August 2012

The role of the vascular endothelial growth factors in neovascular AMD and the features of the VEGF Trap‐Eye molecule are presented including binding mechanism, affinity, and predicted biologic activities that support the rationale for every‐other‐month dosing.
VEGF Trap‐Eye: update on ongoing clinical trials
Authors: LOEWENSTEIN A
Published: August 2012

Studies are underway that investigate the safety and efficacy of VEGF Trap‐Eye in other indications than neovascular AMD, i.e. central retinal vein occlusion (CALILEO and COPERNICUS trials), diabetic macular edema (GALILEO, VIVID&VISTA trials), myopic choroidal neovascularization (MYRROR).
Prevention of ocular hypertension in patients receiving intra‐vitreal steroids
Authors: RADOI C , AFRIAT M , DUCASSE A , ARNDT C
Published: August 2012

Purpose Ocular hypertension is a frequent complication associated with intra‐vitreal injection of corticosteroids, in some cases it may require surgery. The present study was designed to evaluate the benefit of a preventive treatment in patients receiving intra‐vitreal triamcinolone.

Methods A retrospective study of 90 patients treated with intravitreal triamcinolone in one eye is reported. Injections were performed between 2007 and 2011 in the department of ophthalmology at Reims University Hospital. 77 eyes were treated with brinzolamide in the first three months after the triamcinolone injection. 13 were not treated. Brinzolamide was chosen as it has few systemic side effects and no potential pro‐inflammatory action. In both groups, the measurement of the intraocular pressure was performed 7 days, 1,3,6 and 12 months after the injection.

Results A total of 23 cases of ocular hypertension were encountered (25.6%), 14 in the group receiving brinzolamide treatment (18.2%) and 9 in the no treatment group (69.2 %). This difference is statistically significant (p <0.005). The peak intraocular pressure was observed 3 months after the injection in both groups.

Conclusion The limited number of patients in the control group and the retrospective design of the study limits the general conclusions which can be drawn. Although there appears to be a measurable effect of brinzolamide in preventing ocular hypertension, a prospective study is necessary to confirm these preliminary findings.
Clinical and SD‐OCT pattern of retinal venous occlusion with cystoid macular oedema treated with Ozurdex®
Authors: FORTOUL V , DENIS P , KODJIKIAN L
Published: August 2012

Purpose To report our experience with sustained‐release dexamethasone 0.7 mg intravitreal implants (Ozurdex®; Allergan, Inc., Irvine, CA) in first‐line treatment of retinal vein occlusion with macular edema.

Methods 26 patients with a minimum follow‐up time of 6 months (CRVO n=15, BRVO n=11) make up our study. Complete ophthalmic examination including visual acuity, fundus biomicroscopy, fundus photography, fluorescein angiography and spectral domain optical coherence tomography (Cirrus SD‐OCT ; Carl Zeiss Meditec, CA) was performed at baseline and follow‐up (1 week, 1 month, 2 months, 3 months, 4 months, 5 months and 6 months) and tolerance of the implant was assessed.

Results Twenty‐six eyes of 26 consecutive patients treated with a total of 26 sustained‐release dexamethasone 0.7 mg intravitreal implants for macular edema associated with retinal vein occlusion were included. Thirty‐three percent of patients gained at least 3 lines of best‐corrected visual acuity (BCVA) at 2 months. Forty‐four percent of eyes showed SD‐OCT significative decrease of the edema following implant placement at 1 week (p<0.05). Despite an increase of the macular edema in 57% of the eyes at 4 months, the final best‐corrected visual acuity (BCVA) was still better at 6 months than BCVA at baseline. High intraocular pressure (IOP) was mostly controlled with only one medication after OZURDEX. The peak of IOP was noted in 26% of the eyes at 2 months.

Conclusion Sustained‐release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option to control macular edema in patients with retinal vein occlusion. Anatomical and functional benefits of OZURDEX are better when the treatment is done at an early stage.
A retrospective data collection study in patients receiving two or more OZURDEX® injections for macular oedema secondary to retinal vein occlusion
Authors: AUGUSTIN A , HOLZ F , HARITOGLOU C , MEYER W , LOMMATZSCH A , BOPP S , SCHEUERLE A , MAIER M , SEKUNDO W , SANDNER D , MALTMAN J , SHIRLAW A , HATTENBACH L
Published: August 2012

Purpose This retrospective study was designed to investigate the re‐injection interval, efficacy and safety of OZURDEX® in routine clinical practice.

Methods This analysis contains data from 87 patients from 10 sites in Germany who had received at least 2 OZURDEX® injections. Data was collected from the time of the patients’ first injection until 3 – 6 months following their latest OZURDEX® injection.

Results The mean time to OZURDEX® re‐injection between 1st and 2nd treatments was 141 days (5.03 months) in the overall population. Mean time intervals for the BRVO and CRVO sub‐populations were 153 days (5.46 months) and 127 days (4.52 months) respectively. In the overall population, a mean LogMAR BCVA improvement from 0.68 to 0.51 was recorded following the last OZURDEX® injection (mean time of 11.0 weeks post‐injection). For BRVO, mean improvement was from 0.54 to 0.43 (mean time of 10.5 weeks post injection) and for CRVO, 0.83 to 0.58 (mean time of 11.5 weeks post injection). Reductions in central retinal thickness were also observed. Intraocular pressure measurements over 25mmHg were reported in 19.5% of patients. No glaucoma surgeries were reported. 5 patients underwent cataract surgery during the course of the study (4 had known lens opacity at baseline and opacity status data from the 5th was missing).

Conclusion In this real life study, OZURDEX® was found to be safe and effective with repeat treatments. The mean re‐injection interval for RVO patients was 5.0 months.
Evaluation of lower tear meniscus shape with OCT
Authors: BANDLITZ S , PURSLOW C , MURPHY PJ , PULT H
Published: August 2012

Purpose When measuring the tear meniscus radius and calculating tear volume, the anterior radius of the meniscus is assumed to be spherical. This study aimed to define the shape of the meniscus more precisely using high‐resolution optical coherence tomography (OCT).

Methods Images of the lower tear meniscus of 30 normal subjects (8M, 22F; mean age 27.5±9.6yrs), recruited from the patient pool of Höhere Fachschule für Augenoptik, Cologne, Germany, were taken using the Zeiss Cirrus HD OCT. Applying ImageJ software, the tear meniscus height (TMH) was measured and the xy‐coordinates of 12 marked points on the anterior tear meniscus curve were determined. With these coordinates a graph was plotted and the best fitting trend‐line (defining TM curvature) was calculated. Furthermore, the distance between the edge of the lower eyelid and the vertex of the curve (TMH‐V) was calculated and compared to the half TMH (TMH‐H).

Results Mean TMH was 0.24 SD±0.06mm. The mean fitting trend‐line appeared to be a quadratic equation (R‐squared range from 0.908 to 0.996). TMH‐V (0.12±0.04mm) and TMH‐H (0.12±0.03mm) were significantly correlated (r=0.62; p<0.001). The 95% LoA showed that the TMH‐V could be expected to be up to ‐0.07 mm below and 0.07 mm above the TMH‐H.

Conclusion With high‐resolution OCT the anterior surface of tear meniscus was found to have a parabolic shape, which will help to calculate tear volume more precisely. To know the position of the parabolas vertices is useful when explaining the position of light reflexes from the tear meniscus particularly in reflective meniscometry.
Tear film break‐up time evaluation by real‐time wavefront aberrometry in adult patients with meibomian gland
Authors: GICQUEL JJ , DJABAROUTI M , DUPONT L , ZAKARI W , PISELLA PJ , BREMOND‐GIGNAC D
Published: August 2012

Purpose To evaluate tear break‐up time (BUT) with repeated higher order wavefront aberrations (HOA) measurements in adult patients with Meibomian Gland Dysfunction(MGD).

Methods Wavefront aberrations up to the sixth order for a 4‐mm pupil were measured in 10 normal subjects (Group 1) and 10 patients with severe MGD (Group 2) with corneal involvement, using the IRX3 (Imagine Eyes, Orsay, France) Hartmann‐Shack (H‐S) aberrometer. The aberrometry was performed once every second for up to 20 seconds. HOA measurements were performed 3 times in a row. HOA variations were compared with the BUT by the conventional fluorescein method(CFM).

Results There was an excellent correlation between the HOA variation and the BUT recorded by the CFM in both groups. There was also an excellent reproducibility of the HOA measurements in all patients. BUT was significantly decreased (P<0.005) in all patients in Group 2 compared to the normal tests subjects (Group 1).

Conclusion Studying the HOA variation is a valuable method for evaluatingboth the quality visionand the BUT in patients with MGD and evaporative Dry Eye.The IRX3 H‐S aberrometer can be used for an objective and reproducible assessment of the BUT in the follow‐up of patients with severe MGD.
Assessment of angle and anterior chamber changes after keratoplasty
Authors: SICARD F , JANY B , BENNAI D , BREMOND‐GIGNAC D
Published: August 2012

Purpose To quantify angle and anterior chamber changes after corneal transplantation using Visante OCT®

Methods In this retrospective study, Visante OCT® examinations were performed in patients, awaiting keratoplasty, preoperatively(J‐1) and one month postoperatively(M+1). The anterior chamber depth(ACD), the angle‐opening distance at 500µm(AOD), the trabecular‐iris space area at 500µm(TISA) and the scleral spur angle(SPA) in the temporal and nasal quadrants were measured. Patients were classified based on their surgery: the surgery was penetrating keratoplasty(PK group), it was descemet’s stripping automated endothelial keratoplasty(DSAEK group). Preoperative and postoperative measurements were compared using signed rank test of Wilcoxon.

Results Twenty patients were evaluated: fifteen(75%) in the DSAEK group, five(25%) in the PK. Mean anterior chamber depth width increased from 3,31mm(SD 0,69) to 3,35mm(SD 0,341) after PK(p=1) , and from 3,32mm(SD 0,666) to 3,44mm(SD 0,591)after DSAEK(p=0,719). In the temporal quadrant, after DSAEK, mean anterior chamber angle width increased from 0,281mm(SD 0,126) to 0,334mm(SD 0,100)(p=0,03) in the TISA and after PK ,mean anterior chamber angle width decreased from 0,273mm(SD 0,054)to 0,248mm(SD 0,118) (p=0,812). In the nasal quadrant, after DSAEK, mean anterior chamber angle width increased from 0,253mm(SD 0,089) to 0,285mm(SD 0,085)(p=0,207) in the TISA and after PK, from 0,269mm(SD 0,114)to 0,321mm (SD 0,069) (p=0,437).

Conclusion The angle change significantly in the temporal quadrant after corneal transplantation. Larger study need to be perform to confirm the angle changes.
Oximetry in glaucoma: correlation of metabolic changes with structural and functional
Authors: VANDEWALLE E , PINTO LA , OLAFSDOTTIR OB , STALMANS P , VAN CALSTER J , ZEYEN T , STEFANSSON E , STALMANS I
Published: August 2012

Purpose To determine whether retinal vessel oxygen saturation in glaucoma patients is associated with structural optic disc and retinal nerve fiber layer (RNFL) changes and visual field defects.

Methods Retinal oxygen saturation was measured in glaucoma patients with a non‐invasive retinal oximeter (Oxymap ehf, Reykjavik, Iceland). Visuals fields and HRTs were performed on the same day. Statistical analysis was performed using Student’s t‐test and Pearson correlation coefficient when the data were normally distributed: otherwise Spearman correlation was used.

Results The mean oxygen saturation in the arterioles was 97% ± 2%, in venules 65% ± 6% and the arteriovenous (AV) difference was 33% ± 6%. The oxygen saturation in the venules correlated with the visual field mean defects (r= ‐0.42; p=0.001; n=59) as well as with the structural HRT parameters rim area and RNFL (r= ‐0.39; p=0.008 and r= ‐0.26; p= 0.05 respectively; n=53). The AV difference decreased significantly as the visual field defect worsened (r= 0.38; p=0.003), as the rim area diminished (r= 0.29; p=0.03) and as the RNFL decreased (r= 0.27; p= 0.05). No correlation was found between the oxygen saturation in the retinal arterioles and either of these parameters.

Conclusion Severe glaucomatous damage is associated with increased oxygen saturation in retinal venules and decreased AV difference in oxygen saturation. These data suggest that in eyes with severe glaucomatous damage, retinal oxygen consumption is decreased due to tissue loss.
Topical application of AMA0076, a locally acting rho kinase (ROCK) inhibitor, results in a robust IOP control in Dutch Belted Rabbits
Authors: VAN DE VELDE S , VAN BERGEN T , SIJNAVE D , HOLLANDERS K , MOONS L , STALMANS I
Published: August 2012

Purpose To determine the intra ocular pressure (IOP) lowering efficacy of the local ROCK inhibitor, AMA0076, in Dutch Belted rabbits.

Methods Dutch Belted rabbits (5 rabbits/group) received topically a single dose of AMA0076 in one eye. A concentration range of 0.031 ‐ 0.625% AMA0076 was tested. The contralateral eye served as control and was treated with saline. IOP was measured at baseline and 30 min, 1, 2, 3, 4, 5, 6, 7, 8h post topical administration.

Results Single topical administration of AMA0076 significantly lowered IOP in all groups compared to the control eye (p<0.05). Mean baseline IOP during the experiments was between 20.6 and 21.5 mmHg. Thirty minutes after topical treatment, a concentration dependent reduction in IOP was demonstrated with a ΔIOP ranging from 3.9mmHg – 7mmHg compared to the control eye. Maximal IOP reduction of each concentration following single dose administration of AMA0076 was observed ±2 hours after instillation with a ΔIOP ranging from 4.6mmHg and 7.5mmHg. The IOP lowering effect with the highest concentrations of AMA0076 (0.625% and 0.125%) was sustained during the experiment.

Conclusion AMA0076 was effective in rapidly lowering IOP in a dose depended and sustained manner after a single topical dose in Dutch Belted rabbits. This new class of local ROCK inhibitors has potential therapeutic value for the IOP lowering treatment of glaucoma.