bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigenetic alterations in uveal melanoma
Authors: ZESCHNIGK M , SCHOLZ M , LOHMANN DR , THOMAS S , BORNFELD N
Published: September 2008

Purpose Epigenetic alterations are frequently observed in many tumors. Aberrant hypermethylation of CpG rich regions can silence gene expression and, therefore, can result in loss of function equivalent to a null mutation. Recently, regional hypomethylation of CpG rich regions that can result in activation of affected genes has gained increasing attention. Like somatic mutations epigenetic alterations may be used as molecular markers indicating the presence of cancer and minimal residual disease

Methods To study the epigenetic alterations in uveal melanoma we determined DNA methylation by direct sequencing and sequence‐based quantitative methylation analysis (SeQMA) of PCR products from bisulfite treated genomic DNA from primary uveal melanomas, uveal melanoma cell lines, mononuclear blood cells and sperm samples of healthy donors.

Results We have found a frequent epigenetic mutation in the OXTR gene located within a minimal deleted region on chromosome 3p25‐26 in uveal melanoma. Real‐time RT‐PCR showed that OXTR hypermethylation does not affect OXTR expression thus suggesting that this epimutation may affect expression of distant genes. We also identified a CT gene that is hypomethylated and consequently activated in about half of uveal melanomas. Interestingly, hypomethylation of this gene was biallelic.

Conclusion Therefore this alteration is unlikely to be the result of stochastic demethylation processes. We suggest that this region is actively demethylated or selectively protected from maintenance methylation during cell proliferation, or that hypomethylation of CT genes reflects the origin of the malignant cells from an unmethylated progenitor.
Genomic profiling and identification of high‐risk tumours in uveal melanoma by array‐CGH analysis of primary tumours and liver metastases
Authors: COUTURIER J , TROLET J , HUPE P , MARIANI P , SASTRE X , ASSELAIN BERNARD , BARILLOT E , SAULE S , PIPERNO‐NEUMANN S , DESJARDINS L
Published: September 2008

Purpose Current therapeutic efforts in Uveal Melanoma are directed toward detection of liver metastases at an earlier stage and adjuvant systemic therapy in high risk patients. Beside clinical and histological features, specific cytogenetic alterations, particularly monosomy 3 and gain of 8q, are strongly associated with metastasis.

Methods A series of of 78 ocular tumours (OT) (median follow‐up 54 mo.)and of 66 liver metastases (LM), was analysed by CGH on a genome‐wide BAC/DNA microarray (CIT, INSERM U830), with a 1 Mbase average resolution. Correlations were looked for between genomic profiles of OT and the metastatic status of patients, and a prognostic classifier was built, in order to identify tumour profiles of high risk patients.

Results Hierarchical clustering shows that status of chromosome 3 defines two groups of genomic profiles in OT and LM: group 1, with disomy 3, and group 2, with monosomy 3. Seven OT show a partial loss of chr 3, with a minimal deletion of 8.9 Mbase, distal to 3p25.3. Groups 1 and 2 can be subdivided in subgroups according to the presence of additional imbalances. Same genomic groups are found in OT and LM, but with different frequencies. The disomy 3 group represents 20% of metastases. A prognostic classifier including the status of chromosomes 3, 6p, 8p, 8q, 16q, and the position of breakpoint in 8q gains, leads to the best prediction performance in this sample (82%).

Conclusion Genomic profiling by array‐CGH, combined with the allelic status of chromosome 3, should be a robust and reliable approach for identifying high‐risk patients eligible for LM screening and adjuvant systemic therapy.
Use of PLGA microparticles for vitreous staining during anterior vitrectomy
Authors: TINT NL , CHAU DYS , DUA HS , SHAKESHEFF KM , GRIFFIN M , ROSE FRAJ
Published: September 2008

Purpose To demonstrate in vitro the potential use of FDA‐approved PLGA poly(lactic‐co‐glycolic acid) microparticles to aid visualisation of vitreous during anterior vitrectomy following posterior capsule rupture and to compare with the use of triamcinolone suspension.

Methods 10‐60um sized PLGA microparticles were fabricated using the single and/or double emulsion technique(s) and used i) untreated (ii) pre‐treatment with sodium hydroxide (iii) surface adsorption of a protein/synthetic peptide. Particle size, shape, morphology and surface topography were also assessed using scanning electron microscopy (SEM). The efficacy of these microparticles to enhance visualisation of vitreous against triamcinolone suspension was assessed using a simple in vitro set‐up exploiting human cadaveric vitreous.

Results Unmodified PLGA displayed a degree of hydrophobicity and also a high rate of dispersion following repeated wash cycles. Interestingly, surface modified PLGA microparticles demonstrated a significant improvement in its 'vitreophilic' properties and were comparable to a triamcinolone suspension.

Conclusion The use of modified biodegradable PLGA microparticles may represent a novel method of visualising vitreous and aiding anterior vitrectomy. This method may provide a distinct alternative for the visualisation of vitreous without the pharmacological effects of triamcinolone. Furthermore, such a technique allows the incorporation of drugs, growth factors and/or antibiotics within the microparticles which may be desirable in complicated cataract extraction. Animal models are required to assess in vivo biocompatibility of this method.
PASCAL Photocoagulator, is it better ?
Authors: ISSA M
Published: September 2008

Purpose To demonstrate the advantages of the new PASCAL system over conventional laser

Methods Review of new laser modality

Results PAttern SCan Laser is a new retinal (amongst other things) photocoagulator which has many advantages over conventioal laser.It is a fully integradted laser system using frequency‐doubled Nd‐YAG diode pumped solid state laser with short 5532 nm pulses and can deliver anything from a sigle spot or a predetermined patternarray of up to 56 spots at the press of a pedal.

Conclusion PASCAL system delivers a comprehensive range of laser treatments in a considerably shorter time and more comfort and precision in comparison with conventional laser.
Introduction
Authors: DE SMET MD
Published: September 2008

Abstract not provided
An assessive model for corneal endothelium morphometry by diffraction
Authors: BUCHT C , SÖDERBERG PG , MANNEBERG G
Published: September 2008

Purpose Most in vivo measurements on the corneal endothelium morphology are done by specular microscopy. This is a time consuming process, due to the need of operator involvement. To assess alternative methods, an experimental optical setup for corneal endothelium morphometry by diffraction has been created.

Methods A phantom Polymethyl methacrylate (PMMA) cornea was created, having dimensions of a real cornea. The posterior surface of the phantom cornea was grated to allow for identification of a reflected far field (Fraunhofer) diffraction. The grating was manually etched under a microscope and consisted of a quadratic mesh with a periodicity of approximately 80 µm. The phantom cornea was fitted to a phantom anterior chamber. Because of differences in refractive indices, the phantom anterior chamber was filled with a water/sugar solution (61%) to fully emulate the relative reflection of the cornea‐aqueous humor interface. Light from a He‐Ne laser at 632.8 nm was modulated with achromatic lenses towards the phantom cornea at an incident angle of 45 degrees. The light reflected from the phantom cornea‐aqueous humour interface was collected at the opposite 45 degree angle. The Fraunhofer diffraction pattern was recorded with a CCD chip.

Results Experiments showed that a diffraction pattern of the periodicities of the emulated corneal endothelium could be recorded.

Conclusion A simple optical setup was created and a grated emulated cornea was used to assess the possibilities of corneal endothelium morphometry using diffraction. Even with the low reflective power of the emulated cornea‐aqueous humor interface, clear diffraction patterns could be recorded. The result is encouraging for further development of an optical system for in vivo morphometry on the corneal endothelium.
Optimisation of amniotic membrane (AM) denuding for tissue engineering
Authors: HOPKINSON A , SHANMUGANATHAN VA , YEUNG AM , GRAY T , LOWE J , DUA HS
Published: September 2008

Purpose Amniotic Membrane (AM) has gained increasing popularity as a useful carrier for ex‐vivo expanded cells for tissue engineering, particularly in ocular surface reconstruction. However, current methods employed for denuding AM are highly variable and the consequent effects on the structural and molecular composition of the AM basement membrane (BM) are ambiguous. We compare the effects of the main denuding procedures, and propose a highly effective standardised alternative.

Methods AMs preserved for transplantation were denuded using published EDTA and Dispase‐based methodologies and our novel thermolysin‐based procedure. Scanning and Transmission electron microscopy and immunohistochemistry, for BM components (Collgens IV, and VII, laminin 5, and inegrins α6 and ‐β4) were used to assess effectiveness of denuding epithelium, whilst maintaining the integrity of the BM.

Results EDTA and Dispase‐based denuding techniques resulted in the disaggregation and even destruction of the BM structure and molecular composition. Employing thermolysin effectively denuded epithelium whilst maintaining BM structural and molecular integrity.

Conclusion Current procedures for preparing AM are variable and often ineffective, resulting in non standard membranes. Our novel thermolysin‐based technique effectively denudes the AM whilst preserving an essentially intact and consistent BM. Therefore, we propose this novel thermolysin procedure may potentially improve overall generation of tissue engineered constructs using AM.
Morphological link between accommodation, presbyopia and cortical cataract
Authors: MICHAEL R , BARRAQUER RI , VRENSEN G
Published: September 2008

Purpose Evaluation of the gross morphology, the cortical location and the fiber cell architecture of cortical opacities in the aging human lens.

Methods 39 human donor lenses were photographed in toto in frontal view using dark‐field stereomicroscopy. 15 lenses were fixed, cut in axial slices and photographed the same way. Details of fiber cell architecture were investigated by fluorescent staining for membranes and by scanning electron microscopy.

Results Small focal and cuneiform cortical cataracts are discrete opacities located at a specific depth below the capsule, and extending from the equatorial region in anterior and posterior direction. A sharp border is observed, between the opacities with their disorganized fiber architecture and the deeper nuclear layers, which show a regular fiber pattern. This border is at a mean depth of 700 µm below the capsular surface. Close examination of the opacities revealed fiber folds, fiber undulations, fiber‐to‐fiber separations, fiber breaks, water lakes and fiber displacement. Because the lens cortex and nucleus have different viscoelastic properties in young and old lenses, we hypothesize that external forces during accommodation cause shear stress predominantly in this border zone.

Conclusion The location of the described changes suggests that mechanical forces may cause fiber disorganization, small cortical opacities, and, ultimately, cuneiform cataracts. Our hypothesis would be in line with recent findings by Truscott and co‐workers about a two‐compartmental organization of the human lens. They found biochemical arguments for a transport barrier developing at a middle age at the cortical/nuclear interface.
The time of onset of inherited cataract
Authors: BRON AJ , HANNAN F , MUSHTAQ B , KORETZ JF
Published: September 2008

Purpose The lens grows by addition of fibres to its surface, with the newest fibres just under the epithelium anteriorly and the capsule posteriorly. In slit‐section the cortex shows 4 optical zones of dysjunction (C1 to C4) with differing light‐scattering properties. We explore the clock‐like implications of this arrangement and how the spatiotemporal distribution of opacities implies the timing of mutated gene expression and/ or the influence of modifying factors.

Methods Methods: A case report, literature review and proposal of a hypothesis

Results We have observed dot cataract in a mother (42 years) and 2 sons (16 and 11 years) expressing a dominantly inherited, activating mutation of the calcium sensing receptor (CaSR). In each patient, lens opacities were present in the deep and superficial cortex (C2, 3 and 4) but absent from C1 and lens nucleus.

Conclusion In our family, absence of opacities in the lens nucleus implies either that the mutated gene is not expressed pre‐natally or that there is protection from the effects of the mutation in utero, which is lost post‐natally. Absence of opacities in C1 implies the same for these young fibres and suggests that expression of disease (lens opacity) does not occur immediately after birth. We hypothesise that in our family, the expression of lens opacities once these fibres have entered C2, may be related to the switch from aerobic to anaerobic metabolism in the transitions from C1 to C2, to denucleation and loss of organelles and to other structural and functional changes which occur in this region. We suggest that the location and timing of appearance of inherited cataracts is related to the onset of gene expression and the presence of modulating factors which influence the effects of the mutated protein.
In vivo high power infrared radiation exposure time dependence of lens light scattering
Authors: AL‐SAQRY R , GALICHANIN K , LI Y , SÖDERBERG PG , SCHULMEISTER K , HUSINSKI J , BUCHT C
Published: September 2008

Purpose To determine the exposure time dependence of lens light scattering after high power in vivo infrared radiation exposure of the eye.

Methods The experimental animal was 6 weeks old albino SD rat. Altogether, 12 animals were divided into four exposure time groups (5, 8, 13, 20 s). The animals were anesthetized with ketamine‐xylazine, 95/14 mg/kg bodyweight, 20 min prior to exposure and both eyes were dilated with tropicamide 10 mg/ml. The infrared radiation source was a single mode CW fiber laser emitting at 1090 nm (Model SP‐120C, SPI Lasers, UK) with the output power set to 6.2 W. The primary laser beam was focused just in front of the anterior focal point of the eye with an F# close to that of the rat eye so that a divergent beam entered the eye with a spot size of 3 mm in diameter inside the dilated pupil. This allowed for a homogenous intensity distribution within the lens and a large spot size on the retina. One week after exposure, the animal was sacrificed and the lenses were extracted for darkfield macroscopic imaging and measurement of intensity of forward light scattering.

Results The intensity of forward light scattering increased with increasing exposure time. The increase was well described by a 2nd order polynomial, omitting the 0:th and the first order term. The threshold exposure time, estimated as Maximum Tolerable exposure Time (MTT:2.3:16) was 4.8 s. Considering the power used, this corresponds to 30 J, thus delivered over 3 mm diameter which implies a radiant exposure of 4.2 MJ/m2.

Conclusion At 1 week after exposure to 6.2 W of 1090 nm, the intensity of forward light scattering in the lens increases with increasing exposure time and the threshold exposure time is 4.8 s.
Genetic testing in retinal dystrophies
Authors: DOWNES SM
Published: September 2008

Purpose To describe genetic testing in autosomal recessively inherited retinal dystrophies.

Methods Retinal dystrophies (RD) are a heterogeneous group of diseases characterised by progressive retinal degeneration leading to severe visual disability. The prevalence of RD is ~ 1/3500; of these up to 40% are presumed autosomal recessive (AR). AR inheritance is frequently seen in juvenile onset cases, but also presents in young adults. The heterogeneity of inherited eye disease can make differential diagnosis difficult. For a sporadic case in a young male the differential diagnosis may include autosomal recessive, X‐linked or autosomal dominant RD. Although there are no treatments yet available for inherited RD, knowledge of the underlying genetic variation can be helpful for: clinical diagnosis in patients with signs and symptoms of disease; pre‐symptomatic testing for individuals who do not have the disease, but given their family history, are at risk for the disease; carrier testing for individuals who may carry a gene mutation that can be passed on to their children; and may be useful if genetic therapy becomes a viable option. Methods: Testing strategies using novel technologies are now being adopted to increase identification of disease causing mutations. One major advance includes the use of high throughput sequencing platforms. The introduction of this technology is likely to overcome many of the problems associated with testing multiple patient samples and multiple genes, as well as providing the accuracy required in a diagnostic setting. Even these technologies will not identify all types of mutations, for example large deletions so other technologies will be required.
Unusual patterns of orbital extension in periorbital squamous cell carcinomas
Authors: DE KEIZER RJW
Published: September 2008

Abstract not provided
Diagnostic difficulties in orbital pathology
Authors: BONSHEK RE
Published: September 2008

Purpose To describe and discuss sources of difficulty in histopathological diagnosis in orbital pathology and the approach to problematic diagnostic cases.

Methods Review of case material in Manchester Royal Eye Hospital and Manchester National Specialist Ophthalmic Pathology Service Laboratory archives and review of the literature.

Results Problems may be due to inadequacies of the process of specimen submission/handling, eg inadequate clinical information, inadequate sampling or crush/cautery artefact in small biopsies. They may be due to insufficient or uncertain histopathological criteria, eg isolated or rare orbital presentation of systemic pathology (such as isolated orbital Wegener’s granulomatosis), isolated presentation of metastatic malignancy with unknown primary site, anaplastic malignancy and other lesions of uncertain histogenesis, inflammatory lesion vs lymphoreticular neoplasm (such as lymphoid hyperplasia vs low grade B‐cell non‐Hodgkin’s lymphoma and necrotizing inflammation vs T/NK cell lymphoma).

Conclusion Good communication between clinicians and pathologists is essential at all stages during the diagnostic process. Sound morphological assessment remains crucial. Immunohistochemistry plays a valuable part in assisting diagnosis of lesions of uncertain histogenesis and in lymphoreticular pathology. There is an expanding use of molecular genetic analysis. Electron microscopy has largely been supplanted by immunohistochemistry but still has a role to play. Despite the vastly increased technological armamentarium there remain lesions which are very difficult to diagnose or classify. The multidisciplinary team approach fosters interplay among the differing areas of clinical and diagnostic expertise and allows a rational approach to diagnosis and management of problematic cases.
Unexpected orbital and adnexal masses: Experience of several cases
Authors: DRAY JP
Published: September 2008

Abstract not provided
Some unusual vascular mass presentations in the orbit and adnexae
Authors: BONAVOLONTA G
Published: September 2008

Abstract not provided
The effect of corneal hydration on corneal ablation rate at 193nm and 213nm
Authors: PENTARI A , GINIS H , TSATSARONIS D , TSIKLIS N , PALLIKARIS I
Published: September 2008

Purpose The ablation rate of corneal tissue depends primarily on the fluence of the laser and corneal hydration. It was the purpose of the study to compare the dependence of the ablation rate on corneal hydration for two different laser wavelengths (193 and 213‐nm).

Methods ArF Excimer laser (Allegretto, Wavelight) with a wavelength of 193nm and Nd:YAG CustomVis laser with a wavelength of 213nm were used for the study. Corneal discs were harvested from porcine eye within 24 hours post‐mortem. Corneal epithelium was removed with a blunt spatula. The disks received ablation equivalent to the ablation of 100 microns at a circular zone having a diameter of 7mm. Before and after ablation, each disk was weighted and subsequently dried in order to calculate its dry mass and therefore hydration during ablation. In order to test the ablation rate at different hydrations, the disks were ablated at different time intervals fooling their preparation. The hydration ranged from 66 to 80% w/w.

Results The ablated mass showed a positive linear correlation with hydration for both lasers. The corresponding normalised dry mass, which is more critical for the accuracy of refractive corrections, exhibited a negative linear correlation with hydration with similar slopes for the two lasers tested (‐0,0651 for the 193nm and ‐0,0568[hydration‐1] for the 213nm).

Conclusion Results of this study reveal the similar behaviour in the dependence of ablation rate from the hydration of cornea at the 193‐ and 213‐nm laser wavelengths.
Comparison of real intraocular pressure (IOP) during LASIK versus Epi‐LASIK
Authors: CANADAS SUAREZ P , HERNANDEZ ‐ VERDEJO J , DE BENITO L , TEUS M
Published: September 2008

Purpose To compare real‐time intraocular pressure (IOP) in LASIK versus Epi‐LASIK in porcine eyes during flap creation using the Moria 2 microkeratome and the Moria Epi‐KTM epikeratome.

Methods Interventional, prospective study of two keratomes: Moria Group (M2) and epipolis laser in situ keratomileusis Group (MEpi‐K). These devices were used to create a lamellar corneal or epithelial flap respectively in freshly enucleated porcine eyes. The IOP changes induced by the procedures were recorded using manometry by direct cannulation with a reusable blood pressure transducer connected to the anterior chamber.

Results 7 eyes were included for M2 Group and 10 for the MEpi‐K Group. In the M2 Group the IOP increased during suction phase to a mean value of 122.53±30.40 mm Hg and to 160.52±22.73 mm Hg during cutting phase (mean time: 21.42±7.48 and 15.71±1.88 secs respectively). In the MEpi‐K Group, mean IOP increase was 100.66±18.60 mm Hg during suction phase, 91.38±17.79 mm Hg during cutting phase and 74,37±12.70 during low‐back phase (mean time: 25.79±3.44, 33.68±2.81 and 29.74± 3.11 secs respectively). IOP values in both groups showed statistical significant difference in all comparison (p<0.01).

Conclusion Real‐time IOP can be measured during flap creation process using direct manometry in the anterior chamber. Our results show a significant increase in IOP during the surgical procedure in both groups although the IOP increase reached with MEpi‐K epikeratome seems to be lower than M2 microkeratome.
Corneal morphology, topography and sensitivity in a family with inherited recurrent corneal erosions
Authors: NEIRA W , HAMMAR B , HOLOPAINEN J , TUISKU I , DELLBY A , TERVO T , FAGERHOLM P
Published: September 2008

Purpose To assess changes in morphology, corneal topography and sensitivity in a family with inherited recurrent corneal erosion syndrome.

Methods Eighteen family members, 9 affected and 9 unaffected eyes were examined. The affected members represented the different stages of corneal pathology from a nearly normal cor‐nea to anterior stromal fibrosis of the central cornea with discrete corneal irregularities. To evaluate the corneal morphology and nerve structure, the eyes were examined under a corneal confocal microscopy (CCM, ConfoScan 3, Corneal Confocal Microscope. Nidek Technologies). Videokeratography (VK) was evaluated with the Tomey TMS – 2N (Topog‐raphic Modelling System). Corneal mechanical sensitivity was measured with modified Noncontact gas Esthesiometer (NE) (Belmonte modified noncontact esthesiometer, Coop‐erative Research Center for Eye Research and Technology).

Results CCM detected morphological changes in the epithelium and stromal nerves in 5/9 affected eyes. Haze formation with altered keratocytes could be found in the anterior stroma in all affected eyes. Except for two eyes (one affected and one unaffected), all VK showed irregular astigmatism. Corneal sensitivity was significantly lower in affected patients (p <0.01). Age and corneal sensitivity showed no correlation.

Conclusion The decreased sensitivity in the affected eyes seems to correlate with the low number of subbasal nerves reported by CCM. Yet, another possibility is that corneal haze masks the nerves. Correlation between VK and CCM findings in patients was not found. NE revealed a decreased corneal sensitivity in the affected members.
Keratoconic corneas after ferrara rings implantation: histopathological findings
Authors: PERIS‐MARTINEZ C , MENEZO ROZALEN JL
Published: September 2008

Purpose To describe the histopathologic changes in human ectasic corneas, induced after implantation of intracorneal ring segments.

Methods Ten eyes (7 advanced keratoconus, 2 post‐lasik ectasia and 1 marginal pellucid degeneration) recieved corneal implants (Ferrara‐Keraring like) for treatment. Due to a poor refractive out‐come they had penetrating keratoplasty.

Results Conventional histology on all specimens after hematein‐eosin stain, showed no inflammation signs and hypoplasia of the corneal epithelium immediately surrounding the channel.

Conclusion Histopathologic changes seem to be complety reversible after implant removal. Longer follow‐up is necessary to determine whether they accelerate corneal thinning or inflammation response.
Study of the corneal endothelial infection after Herpes simplex virus type 1 (HSV1) in a murine model: comparison between in situ confocal microscopy (ISCM) and immunofluorescent analysis on histological sections
Authors: POGORZALEK N , HUOT N , CREPIN S , FRANCELLE L , OFFRET H , NAAS T , LABETOULLE M
Published: September 2008

Purpose To compare images obtained with ISCM of cornea and immunofluorescence analysis in a mouse model of HSV1 ocular infection (keratouveitis), with the aim of assessing inflammatory reaction (macrophages, lymphocytes and polymorphonuclear cells) and apoptosis during acute infection.

Methods Fifty mice were analyzed using ISCM of left infected corneas, 6 days after HSV1 inoculation. The corneas were then flat mounted, and stained using immmunofluorescence for viral infection, inflammatory markers (macrophages, lymphocytes, PMNs) and apoptosis.

Results ISCM showed multiple retrocorneal cellular precipitates on the inner face of the cornea, with a cluster distribution, and multiple hyper‐ and hypo‐reflective cells randomly distributed all over the endothelium. Histological analysis proved precipitates to be centered by infected endothelial cells and macrophages. Besides, hyper‐ and hypo‐reflective ISCM signals could correspond to either lymphocytes or PMNs, which were found on flat corneas to be scattered onto the endothelium cells, or to apoptotic cells. Most of them corresponded to lymphocytes closely localised near infected endothelial cells (ongoing study).

Conclusion As ISCM images observed in our mouse model were very similar to those observed in human clinical practice with IVCM, our results provide precious information on the biological meaning of clinical observations. In the future, IVCM could be routinely used to monitor herpetic infection in pre‐clinical studies, for example in experiments assessing the efficacy of new antiviral strategies.
Preliminary study of normal tear complement activation in patients with seasonal allergic conjunctivitis outside the season
Authors: VERES A , HAGYO K , MEZEI G , LANG ZS , KRASZNAI M , PROHASZKA Z , FUST G , NEMETH J
Published: September 2008

Purpose to determine whether there is a difference in complement activation level on the ocular surface and tear film stability between seasonal allergic conjunctivitis (SAC) patients outside the season and healthy individuals.

Methods outside the ragweed season asymptomatic ragweed pollen allergic patients with the diagnosis of seasonal conjunctivitis at least during two earlier seasons (n=14, mean age 25.79 ys; 5 male, 14 female) and healthy individuals (n=19, mean age 28.05 ys; 9 male, 5 female) were recruited. We collected tear samples with glas capillaries, measured C3a complement activation product with ELISA, and determined non‐invasive break‐up time (NIBUT) with Keeler TearScope Plus®.

Results the median (range) tear C3a levels were 9.80 (0.78–122.60) ng/ml in SAC patients, and 7.00 (2.00–35.14) ng/ml in the healthy individuals (p=n.s.). The C3a levels did not correlate with sex, age, and the number of seasonal conjunctivitis exacerbations, or NIBUT. The mean NIBUT was 21.50+/‐9.41 seconds in allergic patients and 17.30+/‐8.68 seconds in healthy individuals (p=n.s.).

Conclusion even though a broader complement activation range was detected in seasonal allergic conjunctivitis patients outside the season compared with healthy individuals, there was no significant difference between the two groups. Outside the season the tear film stability was also similar. We assume, the repeated allergic inflammation on the ocular surface did not manifest in tear film instability or increased complement activation in the asymptomatic period.
Topical and subconjunctival bevacizumab in corneal neovascularization in keratoplasty patients
Authors: SCHOLLMAYER P , STUNF S , LAVRIC A , PFEIFER V
Published: September 2008

Purpose To report the clinical use of topical and subconjunctival bevacizumab (Avastin) in keratoplasty patients with corneal neovascularization (NV).

Methods Retrospective case series: nine eyes of nine patients with corneal transplant and corneal NV were studied. NV was graded for depth (superficial, deep), extent (clock hours), centricity and intensity. Three patients received subconjunctival bevacizumab 2.5mg/0.1ml. Five patients were treated with topical bevacizumab 5mg/ml 4 times daily for 1 month. One patient first received injection, followed by topical bevacizumab. Follow up was up to 6 months.

Results Corneal NV partially regressed in 8 out of 9 patients. The extent decreased from 7.4±3.8 to 5.6±3.4 and from 8.7±5.8 to 5.3±4.5 clock hours after treatment in patients that received topical and subconjunctival bevacizumab respectively. The centricity changed only in one patient with eye drops. The greatest effect was seen in intensity with decrease from 2.6±0.5 to 1.4±0.9 and from 2.3±0.6 to 1±0.0 in topical and subconjunctival group respectively. One patient who received both subconjunctival and topical bevacizumab only showed response to topical treatment(decrease in intensity). NV regression was noticed 2 days after injection, response was maximal after 1 week, however NV regrowth started at 1 month follow up in all patients. Decrease in NV in topical group was seen after 1 week with maximum response after 1 month. One patient developed persistent epithelial defect 1 month after injection, no other adverse effects were noted.

Conclusion Topical and subconjunctival bevacizumab may be effective in inducing regression of corneal NV in keratoplasty patients. Further studies are needed to prove the effect and its duration.
Short‐term effect of topical dorzolamide hydrochloride on intrastromal corneal pressure "in vivo" in rabbit corneas
Authors: BOLIVAR G , TEUS M , GUTIERREZ C
Published: September 2008

Purpose To test if treatment with topical dorzolamide influences the intrastromal corneal pressure (ICP) "in vivo" in rabbit corneas.

Methods Interventional, prospective study. Topical dorzolamide (Trusopt 2% eye drops; Merck Sharp & Dohme, Spain) was administered in 7 eyes of New Zealand male rabbits three times daily for three consecutive days, and then the ICP changes were recorded with a reusable blood pressure transducer connected to the mid peripheral cornea. The ICP was measured in the same manner in 7 eyes of New Zealand male rabbits without any topical treatment (control group).

Results The ICP averaged ‐6.2±3.2 mmHg, ‐10±5.8 mmHg and ‐12.5±8.7 mmHg at 15, 30 and 45 minutes in the control group, respectively. In the study group (dorzolamide treated eyes), the ICP readings were 1.8±3.4 mmHg, ‐0.28±4.3 mmHg and ‐1.8±5.3 mmHg at the same time points, respectively. The differences in the ICP between both groups were statistically significantly different at all time points (p=0.004, p=0.005, and p=0.02, respectively).

Conclusion ICP is a valid and sensitive method to evaluate “in vivo” the endothelial function, and that it is more sensitive that other methods in detecting changes in the physiology of this structure with the use of topical dorzolamide.
Dynamic retinal vessel reaction in diabetes type I
Authors: SITNIKOVA D , KOTLIAR K , LANZL I , SIGMUND T , HALLE M , SCHMIDT‐TRUCKSÄSS A
Published: September 2008

Purpose Exposure of the retina to flickering light induces retinal vessel dilation in healthy subjects. Diabetes and related vascular disorders are able to change vascular endothelial function. Whether the dynamic reaction to luminance flicker stimulation in retinal branch arteries and veins differs between healthy volunteers and patients suffering from diabetes type I is investigated.

Methods 35 patients with insulin dependent diabetes mellitus type I (age (mean±SD) 50,9 ± 8,6 years old) and in 35 age and gender matched medically healthy volunteers were examined. Vessel diameters of retinal vessel segments were assessed by Dynamic Vessel Analyzer (DVA). After baseline measurement (50 s) monochromatic rectangular flicker stimulation (530‐600 nm, 12,5 Hz, 20 s) was applied 3 consecutive times.

Results In most subjects fast vessel dilation compared to baseline and an ensuing reactive arterial constriction were observed. In detail we found: .....diabetes.....control mean maximal arterial dilation,[%]:...2,3±1,8**...4,1±2,5 time of max. arterial dilation during the stimulation,[s]:....19,3±10,9*...14,2±3,4 mean maximal venous dilation,[%]:....3,4±1,8*...4,7±1,8 There were statistically significant differences between the two examined groups as marked with *(p<0,05), **(p<0,01) (T‐test).

Conclusion Functional retinal arterial and venous reaction to flicker stimulation differs high significantly between diabetes type I patients and healthy subjects of the same age and gender. Maximal dilation as a response to the stimulus is not reached. These findings might be an indication for alterations in the vascular endothelium and vessel wall rigidity in diabetes, leading to impaired regulation following metabolic demand.
Retinal changes after acute increase of the intraocular pressure in adult mice
Authors: PINILLA I , CUENCA N , SALINAS‐NAVARRO M , FERNANDEZ‐SANCHEZ L , ALARCON‐MARTINEZ L , GARCIA‐MARTIN E , AVILES‐TRIGUEROS M , VILLEGAS‐PEREZ MP , VIDAL‐SANZ M
Published: September 2008

Purpose To investigate the effects of increased IOP on the outer retina and its circuitry.

Methods Adult male swiss mice received a mean of 75 laser impacts (532 nm wavelength, 300 mW power, 0.5 second duration, 100 µm diameter spot size) over the limbar and episcleral veins of the left eye. Intraocular pressure (IOP) was measured with the Tonolab tonometer prior to and at 12 h, and 1, 2, 8 or 20 wks after lasering. Full field ERG responses were recorded from both eyes prior to and 1, 2, 8 or 20 wks after lasering. Mice were processed at 3 (n=5), 8 (n=4) or 12 (n=4) wks after lasering. Cryostat retinal sections were analized by fluorescent confocal microscopy.

Results Laser treatment induced an increase in mean IOP of 130% over baseline 12 hours after lasering but reached basal levels by 1 wk. Three wks after lasering, immunostaining with recoverin and transducin could not document any changes in the ONL, but both ON‐rod bipolar and horizontal cells had lost their dendritic processes in the OPL. Sprouting of horizontal and bipolar cell processes were observed into the ONL. Eight weeks and 12 weeks after lasering, mice with severe impairment of their ERG (disappearance of b‐wave) presented loss of photoreceptor cells. PKC showed morphologic changes of rod bipolar cells and Calbindin showed abnormal and diminished horizontal cells. Immunoreactivity for synaptophysin was decreased and no all the rod bipolar dendrites showed relationship with rod spherules.

Conclusion Increased IOP by laser photocoagulation of the perilimbar and episcleral veins in swiss mice results in changes of retina cell morphology and impairs retinal circuitries.
Early hydroxychloroquine retinal toxicity enhanced by laser flare‐cell meter
Authors: BRAVETTI GO , LEONETTI P , CELLINI M , CAMPOS EC
Published: September 2008

Purpose The aim of this study is the evaluation of the electro‐oculogram (EOG) against the laser flare‐cell meter methodology (LFM) in early detection of hydroxychloroquine retinal toxicity. Several studies have showed that hydroxychloroquine, an antiprotozoal drug used in the treatment of malaria and various rheumatic diseases, can cause severe visual loss due to a toxic effect on the outer retina and the retinal pigment epithelium (EPR).

Methods We enrolled 12 patients (3 males and 9 females) with rheumatoid arthritis (10 patients) and systemic lupus erythematosus (2 patients) in therapy with hydroxychloroquine without retinal toxicity, and 12 health controls (5 males and 7 females). EOG and LFM with a laser flare‐cell meter instruments (FM‐500, Kowa, Tokio, Japan).were performed in all patients and in health controls. The Student’s t test and the Bartlett’s correlation test was performed to compare the results of EOG and LFM with the hydroxychloroquine dose considering significant a p<0.05.

Results The Arden ratio was 188.75±48.94 in patients and 288.33±32.42 in controls (p=0,262); the LFM was 45.80±15.33 vs. 6.31±1.12 photons/ms(p<0.030). The Bartlett’s test showed a strong correlation (p<0.022) between the flare and the total hydroxychloroquine dose (394.16±53.84 mg).

Conclusion The flare is an index of anterior segment subclinical inflammation. The proteins level increase in many pathologies, especially in case of an alteration of pigmented cells of iris and ciliar body. These cells have the same origin of EPR and could be damaged by the hydroxychloroquine. In conclusion we can say that the laser flare‐cell meter could be an easier, quickly and more sensibly exam than EOG to detect early hydroxychloroquine toxicity.
Lactate‐induced retinal vasodilation implicates neuronal nitric oxide synthesis in minipigs
Authors: MENDRINOS E , PETROPOULOS IK , MANGIORIS G , PAPADOPOULOU DN , STANGOS AN , POURNARAS CJ
Published: September 2008

Purpose To investigate the role of neuronal nitric oxide (NO) synthesis in the retinal vasodilatory response to lactate in minipigs

Methods Ten eyes of 10 minipigs were evaluated.After 1 hour of intravenous infusion of Nω‐nitro‐L‐arginine methylester (L‐NAME),an intravitreal juxta‐arteriolar microinjection of 30µl of L‐lactate 0.5 mol/l (pH= 7.4) was performed through a micropipette.Ten minutes later, an intravitreal juxta‐arteriolar microinjection of 30µl of L‐NAME 0.01 mol/l (pH= 7.4) was performed in all eyes but one which received balanced saline solution (BSS).Retinal arteriolar diameter changes were measured in vivo using a Retinal Vessel Analyzer.The animals’ vital signs were monitored and systemic arterial pressure was maintained stable

Results Retinal arteriolar diameter decreased by 4.1% 1 hour after intravenous L‐NAME infusion compared to baseline but the difference did not reach significance.Juxta‐arteriolar injection of L‐lactate induced a significant increase in retinal arteriolar diameter of 22.7% and 28.7% at 5 and 10 minutes respectively(p<0.01). This was followed by a significant decrease of 8.6% 10 min after juxta‐arteriolar injection of L‐NAME(p<0.01).Injection of BBS had no effect in the control eye and retinal arterioles remained dilated under the effect of L‐lactate

Conclusion Juxta‐arteriolar administration of L‐lactate induced vasodilation despite inhibition of endothelial‐derived NO by the continuous intravenous infusion of L‐NAME. Moreover,juxta‐arteriolar L‐NAME microinjection significantly suppressed the vasodilatory effect of L‐lactate.These data suggest that neuronal‐derived NO is an important mediator of the lactate‐induced vasodilation in minipigs
Flame‐shaped hemorrhage seen in diabetic retinopathy is indicative of macular ischemia
Authors: KABASAWA SK , SIBUYA MS , YONEYA SY
Published: September 2008

Purpose To study oxygen saturation(OS) levels in the macula with non‐proliferative diabetic retinopathy.

Methods 60 eyes of 46 diabetic patients were enrolled in this study. The eyes were divided into three groups based on additional fundus findings. 16 eyes had flame‐shaped hemorrhages near the optic disk(group H). 20 eyes had soft exudates throughout the fundus(group E) and 24 eyes had neither flame‐shaped hemorrhages nor soft exudates (group N). Patient`s age were 57±9.6, 58±8.5 and 54±16.2 years, respectively in each group. Exclusion criteria were eyes with macular edema treated with laser coagulation. The extent of capillary non‐perfusion was evaluated using fluorescein angiogram divided into macula and 4 peripheral quadrants. The severity of non‐perfusion was graded from 0 to 5 in a masked fashion. The OS level was measured only in the macular area using Fourier transform‐based spectral retinal imaging (SRI) system (Retinal Cube;ASI Co.Israel).

Results The OS levels in the macula did not correlate with overall extent of capillary non‐perfusions in the fundus. However group H showed a tendency to have lesser area of capillary non‐perfusion when compared with group E or N. The OS levels of H,E and N group were 63±6.7,68±6.2,and 74±8.5% respectively. The difference between OS levels in group H and N and between group E and N were statistical significance (p<0.01 and p<0.05 respectively).

Conclusion The OS levels in the macular area of the retinas with non‐proliferative retinopathy were lowest in the retinas with flamed‐shaped hemorrhage. Surprisingly, the overall degree of capillary non‐perfusion of the fundus did not correlate with macular OS level. Our study shows that flame shaped hemorrhages are indicative of macular ischemia.
Intravitreal bevacizumab for vitreous hemorrhage
Authors: LIBONDI T , JONAS JB , VON BALTZ S , VOSSMERBAEUMER U
Published: September 2008

Purpose Vitreous hemorrage is one of the major complications of ischemic retinopathies such as diabetic retinopathy. Our purpose was to describe the clinical outcome of patients who underwent a less invasive intervention than vitrectomy for therapy of persisting vitreous hemorrage

Methods Our clinical interventional case series study included 10 patients (n=11 eyes) who presented with vitreous hemorrage due to proliferative diabetic retinopathy (n=10 eyes)or ischemic retinal vein occlusions (n=1). The hemorrage had persisted for at least 3 months. Mean age was 62,1+/‐14,5 years (median 58.4 years; range 45.8‐90.8 years) and mean visual acuity was 1,65+/‐0.97 logMAR. The mean intraocular pressure was 14.6+/‐3.6 mm Hg. All eyes received an intravitreal injection of 1.25 mg bevacizumab, which was repeated in 2 eyes (17%). All patients were fully informed about the experimental character of the treatment and signed an informed consent.

Results At the end of follow‐up at 3.9+/‐2.3 months (range 1‐6 months) after the first injection, the vitreous hemorrage had cleared without any further intervention in all but 1 (9%) eye. Visual acuity improved significantly (p=0.02) from 1.65+/‐0.97 logMAR to 0.98+/‐0.67 logMAR. The intraocular pressure remained in the normal range (mean 14.6+/‐3.5 mm Hg) with no significant difference to the baseline values (p=0.94). We did not observe any sign of intraocular inflammation or other changes that could be regardesd as side‐effects of the intravitreal injecion. 4 (36%) eyes underwent panretinal laser coagulation after clearing of the vitreous hemorrage.

Conclusion The present study may suggest to extend the intravitreal use of bevacizumab to persisting vitreous hemorrage due to ischemic retinopathies.
Effect of diabetes mellitus on NGF and NGF‐receptor distribution in retinal ganglion cells and vascularity in adult rats
Authors: COLAFRANCESCO V , BUCCI M , ALOE L
Published: September 2008

Purpose Recent studies reported that NGF exerts a protective action on cells of the visual system, including retinal cells, and that eye topical application of NGF can reach brain NGF‐responsive cells. The aim of the present study is to investigate the response of NGF, NGF‐receptor and VEGF in retinal cells in a rat model of DM.

Methods Adult SD rats were obtained from local animal facilities, maintained in a 12:12‐hr light:dark cycle and had free access to tap water and food through out the experiments. Rats received a single intraperitoneal injection with 70mg/kg body weight of Streptozotocin (STZ) dissolved in PBS. Control rats received an equivalent volume of buffer solution. Animals were sacrificed with an overdose of Nembutal and pancreas, retina, optic nerve and lachrymal gland removed and used for biochemical, immunohistochemical, and molecular analysis. NGF was determined with “NGF Emax Immunoassay System” ELISA kit by Promega (USA). For histological and immunohistochemical analysis, eye globes were fixed in Bouin fluid. Twenty µm thick sections were cut with a cryostat at ‐20°C and immunostained for localization of NGF, NGF‐receptors, or vascular endothelial growth factor.

Results DT lowers the presence of NGF in the whole retina and reduces the number of retinal cells, particularly in the retinal ganglion layer, and the presence of retinal vessels. NGF administration markedly reduces these deficits.

Conclusion The present findings support the hypothesis of a NGF role in retinal cell physiopathology and suggest that eye NGF application might be useful to prevent and/o reducing retinopathy induced by DT. *V. Colafrancesco has a fellowship supported by Bietti Foundation, Roma
VEGF/Ang‐2 imbalance: the crosslinking between methylglyoxal and vascular dysfunction in diabetic retinopathy
Authors: BENTO C , FERNANDES R , PEREIRA P
Published: September 2008

Purpose Accumulation of methylglyoxal (MGO) in retinas of diabetic rats has been implicated in the formation of acellular capillaries, suggesting an important role for MGO in the vascular dysfunction observed in diabetes. In this study, we hypothesize that increased levels of MGO in retinal pigment epithelium (RPE) cells disturbs the balance VEGF/Ang2 secreted to the extracellular milieu, promoting apoptotis and low proliferation of endothelial cells.

Methods ARPE19 cells were subjected both to hypoxia and MGO, two main features of diabetic retinopathy (DR). The levels of VEGF and Ang2 secreted into the culture medium were assessed by ELISA. Retinal endothelial cells were subsequently treated with the pre‐conditioned media of the ARPE19 cells, as well as with different ratios of VEGF and Ang2 recombinant proteins. Apoptotic cell death was determined by immunoblot against Bax and Bcl2, while endothelial cell proliferation was assessed by BrdU‐incorporation and fibrin gel angiogenic assays.

Results MGO increases the levels of Ang2 and strongly decreases the levels of VEGF secreted by ARPE19 cells in response to hypoxia. VEGF downregulation appears to result from increased degradation of HIF1α and low HIF1 transcriptional activity. The VEGF/Ang2 imbalance generated by MGO significantly increases the expression of BAX and decreases the levels of Bcl2 of endothelial cells. Moreover, this imbalance also leads to decreased proliferation of the endothelial cells.

Conclusion The VEGF/Ang2 imbalance induced by MGO activates the apoptotic cascade and induces low proliferation of retinal endothelial cells, possibly leading to vessels regression in pathologies that favour accumulation of MGO and where hypoxia is also present, such as DR.