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Anterior Segment (anterior + segment)
Terms modified by Anterior Segment Selected AbstractsVitiligo and ocular findings: a study on possible associationsJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2006E Bulbul Baskan Abstract Objective, In this study, we aimed to evaluate the ocular findings in vitiligo patients and reveal any clinical feature that might suggest an association or a risk factor. Background, Very few reports in the literature are available about the ocular findings in vitiligo and the possible associations of the ocular findings in vitiligo patients have not been studied so far. Methods, A total of 45 patients with previously documented cutaneous vitiligo were examined for ocular findings. Demographic features including age, gender, duration of vitiligo, presence of associated autoimmune diseases, type of vitiligo and the anatomical distributions of vitiligo were recorded to evaluate a possible relationship with the ocular findings. Univariate and multivariate analyses as well as cluster analysis were performed. After description of the clusters, the Mann,Whitney U -test and Fisher's exact test were used to determine the variables. Concordance among the variables in each group was evaluated with the McNemar test. Results, Ten patients had ocular findings that included anterior segment (iris) involvement, ring-like peripapillary atrophy around the optic nerve, atrophy of pigment epithelium, focal hypopigmented spots and diffuse hypopigmentation. The presence of periorbital vitiligo was significantly related to the ocular findings. Cluster analysis revealed concordances between periorbital and genitalial localizations of vitiligo and ocular findings. Conclusion, The number of patients and the range of ocular findings in our study are insufficient to make definite conclusions but anatomical localizations, primarily periorbital and to a lesser extent genitalial vitiligo, seem to be the most probably alerting features for ocular findings. [source] Relationship between eye symptoms and blepharospasm: A multicenter case,control studyMOVEMENT DISORDERS, Issue 12 2005Davide Martino MD Abstract Although patients with primary blepharospasm (BSP) commonly report experiencing ocular symptoms before the onset of orbicular spasms, the precise frequency and pathogenic role of this subjective ocular discomfort are poorly understood. We conducted a multicenter case,control study to investigate symptoms related to disorders of the anterior segment of the eye, administering a questionnaire to 165 patients with BSP and 180 age- and gender-matched control patients with hemifacial spasm. On a validation sample, our questionnaire yielded high accuracy in detecting eye diseases (predominantly, dry eye syndrome) using detailed ophthalmological examination as the criterion. Logistic regression analysis indicated a significant association between ocular symptoms at disease onset and BSP. Ocular symptoms starting in the year preceding disease onset (short-latency symptoms) showed a stronger association with BSP than ocular symptoms occurring earlier in time (long-latency symptoms). The association was stronger when short-latency symptoms developed from 40 to 59 years of age, whereas this was not observed for long-latency symptoms. Our findings support the view that eye symptoms associated with BSP result from eye diseases and may be involved in the pathogenesis of BSP. The differential risk of developing BSP, based on age at onset of ocular symptoms, suggests that age and eye diseases may interact in giving rise to BSP. © 2005 Movement Disorder Society [source] Environmental Effects on the Photochemistry of A2-E, a Component of Human Retinal Lipofuscin,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2001Laura Ragauskaite ABSTRACT Several retinal dystrophies are associated with the accumulation of lipofuscin, a pigment mixture, in the retinal pigment epithelium (RPE). One of the major fluorophores of this mixture has been identified as the bis-retinoid pyridinium compound, A2-E. Because this compound absorbs incident radiation that is transmitted by the anterior segment of the human eye, photophysical and photochemical studies were performed to determine if A2-E could photosensitize potentially damaging reactions. Steady-state fluorescence measurements indicate that the fluorescence emission maximum and quantum yield are very sensitive to the chemical environment and a correlation between these two parameters and the solvent dielectric constant is observed. Time-resolved absorption experiments of A2-E in pure organic solvents showed no formation of transient species on the timescale of our experiments. However, when these measurements were repeated for A2-E in Triton X-100 micelles, a short-lived (,, 14 ,s), weak absorption was observed. This species is quenched by oxygen (k= 2 × 109M,1 s,1) and by the addition of the antioxidants, cysteine and N,N,N,,N, -tetramethylphenylenediamine. Quenching of this species by 2,3,5-trimethylhydroquinone results in the formation of the 2,3,5-trimethylsemiquinone free radical and an increase in yield of the A2-E,derived species. Sensitization of the A2-E triplet excited state indicates that the species observed in micelles upon direct excitation is not consistent with the triplet excited state. Based on these data we tentatively assign this absorption to a free radical. In the RPE these initial processes can ultimately lead to damage to the tissue through the formation of peroxides and other oxidized species. [source] 3422: Sources of straylight in the human eyeACTA OPHTHALMOLOGICA, Issue 2010D DE BROUWERE Purpose Besides refractive aberrations, ocular light scattering is a major parameter affecting image quality on the retina in healthy eyes. Several pathologies in the anterior segment such as corneal scarring and cataract cause significant increase of straylight in the eye. In this study, we link morphologic changes addressed to corneal scarring to a scattering function. Methods Excised rabbit corneas with different grades of scarring following photorefractive keratectomy were optically evaluated for their forward light scattering distribution and consecutively prepared for histology. An absolute parameter for forward scattering was calculated based on the readings in the optical device. We compared this parameter to the relative thickness of the scar tissue observed in the histological data. Results The histological data showed a wide variation of thickness a scar tissue layer in the anterior stroma. The scattering ratio measured using the optical device measuring forward light scattering correlated strongly with the relative thickness of the scar tissue layer with (0.63, Pearson's coefficient), as well as a standard haze exam (measuring backscattered light) (0.51, Pearson's coefficient). The light scattering distribution is narrowly forward peaked (FWHM 30 arcmin), suggesting this light scattering is caused by large particles such as myofibroblasts, oedema or irregular scar tissue in the ablated zone. Conclusion Corneal light scattering associated with the increased amount of haze after excimer laser ablation has a narrowly forward distribution that can be attributed to the subepithelial structures observed in treated corneas. This is in contrast to the origin of scatterers linked to cataract, as small protein aggregates and multilamellar bodies that are scattering over wider angles. [source] 3353: Response of the human eye against oxidative stress at high altitudesACTA OPHTHALMOLOGICA, Issue 2010S KARAKUCUK Purpose To evaluate the response of the anterior segment of the eye against oxidative stress during acute exposure to high altitudes. Methods Forty volunteers were examined and measurements performed at Erciyes University Medical Faculty,Ophthalmology Clinic, Kayseri,Turkey(1080m). On the following day, participants were transported to Mt. Erciyes Ski Center by bus(2200m); thereafter they climbed to an altitude of 2800m.with a moderate pace. Central corneal thickness, intraocular pressure,spheric equivalent of refraction, arterial oxygen pressure,blood pressure, pulse rate and body temperature were measured at both altitudes. Venous blood samples were taken from volunteers at both altitudes;total oxidant status (TOS),total antioxidant status(TAS),advanced oxidation protein products (AOPP), xanthine oxidase (XO), thiol, adenosine deaminase(ADA)levels were investigated at 1080m and 2800m. Results TOS(7.02µmol H2O2 equiv/L, range:0.49-22.07) and AOPP(220.74µmol/L,range:103.81-667.35)significantly increased at high altitude, compared to low altitude levels (3.32µmol H2O2 equiv/L range:0.92-18.41,and 195.58µmol/L,range:84.77-663.16, resp; p<0.05).IOP significantly elevated at high altitude (14.45±3.54mmHg vs 13.22±2.74mmHg; p<0.05). There was a significant positive correlation between IOP and TAS levels(p<0.05). No significant correlation was found between spherical equivalent or central corneal thickness with the investigated oxidation parameters at both altitudes Conclusion We conclude that oxidative stress markers, TOS and AOPP are increased along with IOP during acute exposure to hypoxic environment at high altitudes and that antioxidant system may have a limited capacity to counter balance this effect because of acute unacclimatized ascent. [source] 4141: Visual phenotyping at the "Institut Clinique de la Souris"ACTA OPHTHALMOLOGICA, Issue 2010MJ ROUX Purpose Visual diseases come in many flavors, with a large variety of affected tissues (eye anterior segment, retina, optic nerve, cortex ,), ages of onset, rate of progression and causal factors. In Western countries, if the majority of these diseases are now curable, millions of people are still affected by blindness or low vision, as many retinal diseases (age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy, glaucoma,) still lack efficient treatments. In a facility devoted to mouse phenotyping as the Mouse Clinic Institute (MCI), it is thus of major importance to propose an efficient visual phenotyping platform, to pick up visual defects in screened mutants, to assess the beneficial effects of potential treatments or the eventual adverse effects of drugs targeting the CNS. Methods Methods: Mouse mutant lines from the Eumodic European project, as well as lines from specific academic projects, go through clinical observation (slit lamp, fundus imaging) in the context of a behavioral phenotyping pipeline, or are assessed in more details with angiography, optomotor response, electroretinography, retinal histology and/or immunohistochemistry. Results To illustrate the possibilities offered by the MCI visual phenotyping platform, we will present results obtained from various projects, as well as the validation of electroretinography protocols to follow dark adaptation and the effect of acute drug injections. Conclusion In an environment allowing for an in depth phenotyping, from behavior to biochemistry, metabolism and cardiology, the MCI visual phenotyping platform provides a comprehensive set of tests to get the most out of genetically modified mice. [source] 2414: Laser and vitrectomyACTA OPHTHALMOLOGICA, Issue 2010E STEFANSSON Purpose Modern vitreous surgery involves a variety of treatment options in addition to vitrectomy itself, such as photocoagulation, anti-VEGF drugs, intravitreal steroids and release of vitreoretinal traction. A full understanding of these treatment modalities allows sensible combination of treatment options. Methods Vitrectomy reduces the risk of retinal neovascularization, while increasing the risk of iris neovascularization, reduces macular edema and stimulates cataract formation. These clinical consequences may be understood with the help of classical laws of physics and physiology. The laws of Fick, Stokes-Einstein and Hagen-Poiseuille state that molecular transport by diffusion or convection is inversely related to the viscosity of the medium. When the vitreous gel is replaced with less viscous saline, the transport of all molecules, including oxygen and cytokines, is facilitated. Oxygen transport to ischemic retinal areas is improved, as is clearance of VEGF and other cytokines from these areas, thus reducing edema and neovascularization. At the same time, oxygen is transported faster down a concentration gradient from the anterior to the posterior segment, while VEGF moves in the opposite direction, making the anterior segment less oxygenated and with more VEGF, stimulating iris neovascularization. Results Retinal photocoagulation has also repeatedly been shown to improve retinal oxygenation. Oxygen naturally reduces VEGF production and improves retinal hemodynamics. The VEGF-lowering effect of photocoagulation and vitrectomy can be augmented with anti-VEGF drugs and the permeability effect of VEGF reduced with corticosteroids Conclusion Vitrectomy and laser retinal treatment both improve oxygenation of the ischemic retina, reduce VEGF formation and thereby reduce neovascularisation and edema. [source] 4268: Metadifferentiation of iris nevi after iridectomy: a clinicopathological small case series.ACTA OPHTHALMOLOGICA, Issue 2010A SCHALENBOURG Purpose Iridectomy of suspicious pigmented tumors provides the presumed advantage of both a histopathological diagnosis and treatment of the lesion. We present 2 patients that developed an iris melanoma with extrascleral extension at the site of their iridectomy of a histopathologically proven nevus, 46 and 2.5 years later. Methods Retrospective, clinicopathological small case series of 2 patients. Results Two patients underwent iridectomy for a suspicious tumor, the first in 1963 and the second in 2006. Pathological diagnosis was a benign and a borderline nevus respectively. In 2009, both patients presented with a recurrent melanocytic iridociliary tumor with an extrascleral extension adjacent to the surgical scar. Pathological examination confirmed melanoma. Consequently, the two patients underwent proton beam therapy of the whole anterior segment, with limbus deposition and reposition. Conclusion Iridectomy of a histopathologically proven nevus doesn't exclude the possibility of a metadifferentiation of remaining nevus cells into melanoma, even after 46 years. Additionally, treatment in case of a recurrence is more complicated than a primary radiotherapy of the unbiopsied iris tumor, with clinical proof of growth, would have been. [source] 4333: How does scleral buckling affect the anterior segment of the eye?ACTA OPHTHALMOLOGICA, Issue 2010FJ ASCASO Purpose To describe the modifications produced in the anterior segment of the eye after placing an encircling scleral buckling (SB) in terms of corneal morphology, biomechanics and intraocular pressure. Methods A prospective study of 15 eyes with rhegmatogenous retinal detachment who underwent pars plana vitrectomy combined with a scleral buckle (PPV/SB), and 12 eyes with vitreous hemorrhage treated with PPV alone. We measured preoperatively and 1-month after surgery the corneal biomechanical properties using the Ocular Response Analyzer (ORA), including corneal hysteresis (CH), corneal resistance factor (CRF), intraocular pressure (IOPg), and corneal compensated IOP (IOPcc). Moreover, we defined the corneal morphology by 4 parameters provided by the topographer Orbscan IIz: mean corneal power (dioptres), standard deviation, thinnest point (µm), and anterior chamber depth (ACD) (mm). Results Mean CH values were significantly diminished following PPV/SB (p=0.003). We found no significant changes in CRF. IOPg and IOPcc mean values were significantly increased only in the PPV/SB group (p=0.019 and p=0.010, respectively) but not in PPV group (p=0.715 and p=0.273, respectively). In PPV/SB group, IOPcc mean values were significantly higher than IOPg before (p=0.001) and after surgery (p=0.003), but not in the other group. None of the morphological parameters were modified after surgery in any of the two study groups (p>0.05) Conclusion Anterior segment morphology was not modified after placing a SB. Corneal biomechanical properties showed a reduction in CH, probably due to a vascular constriction and reduction of the eye compliance. PPV might be considered a less invasive approach for the repair of noncomplex retinal detachments than PPV/SB. [source] Involvement of intraocular structures in disseminated histoplasmosisACTA OPHTHALMOLOGICA, Issue 4 2010Marianne Ala-Kauhaluoma Abstract. Purpose:, To describe ocular involvement and response to treatment in a patient with human immunodeficiency virus (HIV) infection with severe progressive disseminated histoplasmosis (PDH). Methods:, We report a 35-year-old HIV-infected patient seen in our clinics over a period of 4 years. During antiretroviral treatment (ART), the HIV load became undetectable at 3 months; however, CD4 T-cell count increased slowly and rose to 100 cells/,l. Histoplasma capsulatum was cultured from skin pustules, cerebrospinal fluid (CF) and aqueous humour. Results:, The patient developed central nervous system (CNS) involvement 2 months and panuveitis in both eyes 4 months after the initiation of ART. With intravenous liposomal amphotericin B followed by oral voricanozole, the chorioretinal lesions of the right eye (RE) became inactivated and magnetic resonance imaging (MRI) lesions of CNS disappeared. Relapse of the inflammation in the anterior segment of the left eye (LE) resulted in a total closure of the chamber angle and severe glaucoma. Despite medical therapy, two cyclophotocoagulations, total vitrectomy and repeated intravitreal amphotericin B injections, LE became blind. Histoplasma capsulatum was cultured from the aqueous humour after antifungal therapy of 16 months' duration. Conclusion:, PDH with intraocular and CNS manifestations was probably manifested by an enhanced immune response against a previous subclinical disseminated infection. It seems difficult to eradicate H. capsulatum from the anterior segment of the eye in an immunocompromised patient. [source] Epidemiology of exfoliation syndrome in the Reykjavik Eye StudyACTA OPHTHALMOLOGICA, Issue thesis3 2009Ársćll Már Arnarsson Abstract. Exfoliation syndrome (XFS) is a major risk factor for glaucoma. It is characterized by a pathological accumulation of polymorphic fibrillar material in the anterior segment of the eye. It is likely that the increase in intraocular pressure (IOP) seen in XFS patients is at least in part because of flakes of material clogging up the trabecular meshwork, and thereby increasing the resistance to outflow and increasing IOP. XFS glaucoma progresses more rapidly, is more resistant to medical treatment and has worse prognosis than other glaucomas. The prevalence of XFS has been found to vary greatly between different studies, raising the possibility of racial and/or environmental modulators. XFS has also been linked to other changes in ophthalmological structures such as; changes in central corneal thickness (CCT), steeper corneal curvature (CC) and nuclear lens opacifications. Some studies have found XFS to be associated with systemic diseases, mostly cardiovascular and cerebrovascular. Exposure to ultra-violet (UV) light has also been investigated as a possible culprit, along with several other plausible factors. The aim of the present study was to determine the prevalence and 5-year incidence of XFS, to establish possible risk factors and/or concomitant symptoms and finally to investigate the relationship between XFS and glaucomatous changes. The Reykjavík Eye Study (RES) is a prospective study based on a random sample from the Icelandic national population sample. The baseline examination was performed in the autumn of 1996, when 1045 persons older than 50 years participated. Of these, 846 (88.2% of survivors) participated in a follow-up 5 years later. All participants went through a standard examination protocol, and answered a comprehensive questionnaire on health and life style. In the prevalence study, XFS was found in 10.7% of subjects, more frequently in women and older persons. Five years later, a further 5.2% of those that participated in the follow-up study and had no signs of XFS at baseline were diagnosed having XFS. We found a strong correlation between IOP and XFS. No difference was found in the anterior segment parameters measured, but there was a significant loss of neural tissue in the XFS as demonstrated by measurements of cup/disk ratio. In conclusion, we find XFS to be frequent among Icelanders, increasing with age and more in women. Our diagnostic criteria are reliable over time. We have also identified possible risk factors that point to a role of antioxidants in the development of XFS. We find changes in corneal curvature and thickness more related to age than XFS. [source] Fine-needle aspiration biopsy and other biopsies in suspected intraocular malignant disease: a reviewACTA OPHTHALMOLOGICA, Issue 6 2009Nils Eide Abstract. Ocular oncologists require a strong indication for intraocular biopsy before the procedure can be performed because it carries a risk for serious eye complications and the dissemination of malignant cells. The purpose of this review is to evaluate the extent to which this restricted practice is supported by evidence from previous reports and to outline our main indications and contraindications. The different intraocular biopsy techniques in the anterior and posterior segment are discussed with a focus on our preferred method, fine-needle aspiration biopsy (FNAB). In the literature, complications are typically under-reported, which reduces the possibilities of evaluating the risks correctly and of making fair comparisons with other biopsy methods. In FNAB, the exact placement of the needle is critical, as is an accurate assessment of the size of the lesion. Fine-needle aspiration biopsy is usually not a reliable diagnostic tool in lesions < 2 mm in thickness. It is very advantageous to have a cytopathologist present in the operating theatre or close by. This ensures adequate sampling and encourages repeated biopsy attempts if necessary. This approach reduces false negative results to < 3%. Adjunct immunocytochemistry is documented to increase specificity and is essential for diagnosis and management in about 10% of cases. In some rare pathological processes the diagnosis depends ultimately on the identification of specific cell markers. An accurate diagnosis may have a decisive influence on prognosis. The cytogenetic prognostications made possible after FNAB are reliable. Biopsy by FNA has a low complication rate. The calculated risk for retinal detachment is < 4%. Intraocular haemorrhage is frequently observed, but clears spontaneously in nearly all cases. Only a single case of epibulbar seeding of malignant cells at the scleral pars plana puncture site of transvitreal FNAB has been documented. Endophthalmitis has been reported and adequate standard preoperative preparation is obligatory. An open biopsy is still an option in the anterior segment, but has been abandoned in the posterior segment. Although vitrectomy-based procedures are becoming increasingly popular, we recommend using FNAB as part of a stepwise approach. A vitrectomy-assisted biopsy should be considered in cases where FNAB fails. In any adult patient with suspected intraocular malignancy in which enucleation is not the obvious treatment, the clinician should strive for a diagnosis based on biopsy. When the lesion is too small for biopsy or the risks related to the procedure are too great, it is reasonable to be reluctant to biopsy. The standards applied in the treatment of intraocular malignant diseases should be equivalent to those in other fields of oncology. Our view is controversial and contrary to opinion that supports current standards of care for this group of patients. [source] Glaucoma associated with KProsACTA OPHTHALMOLOGICA, Issue 2009K HILLE Purpose Glaucoma is one of the most serious problems in Keratoprostheses. Already glaucoma is very frequent in patients with severe changes of the ocular surface requiring keratoprosthesis surgery. About 50% of those patients have pre-existing secondary glaucoma. Preoperatively all efforts should be done to detect its presence very early on. In KPro detection of glaucoma with traditional aids is difficult. A rough estimation of the tension by digital palpation will be the only available method. All indirect clues such as the medical history of glaucoma, echographic signs of disc cupping and anterior synechiae and examination of the visual field should be considered. Methods The incidence of postoperative secondary glaucoma vary among the different kinds of prostheses according to the surgery affecting the anterior segment and the long term anatomic results. In Osteo-Odonto-Keratoprostheses (OOKP) the most vision threatening complication is a primary or secondary glaucoma, due to the extended interventions required in the anterior segment. In Boston Keratoprostheses the risk seems to be somehow less. Results As the absorption of topical anti-glaucomatous medication will not reach the inner eye because of the anatomic barrier in KPro the only promising possibilities of treatment are systemic carbonic anhydrase inhibitors, different kinds of aqueous shunts and endo-cyclo-laserphotocoagulation. Conclusion Glaucoma is still a mayor problem in KPro. PS: This lession will be presented at the KPro-Meeting!! [source] Slitlamp integrated OCT, what you can see, is what you can scanACTA OPHTHALMOLOGICA, Issue 2009FD VERBRAAK Purpose To present results of OCT images captured of the posterior and anterior segment of the eye using the SLSCAN-1, a new FD-OCT device integrated into a slit lamp. Methods Patients, seen in the outpatient clinic of the Academic Medical Center, were scanned with the SLSCAN-1, a newly developed OCT scanning device, integrated into a common slit lamp (figure 1). The OCT is a Fourier Domain OCT system (SLD light source, central wavelength 830 nm, bandwidth 30 nm, 1024 pixel CCD camera, scan speed 5k A-scans per second, 1024 A-scans per B-scan). The posterior segment scans have been captured using a standard indirect ophthalmic lens (Volk). A color fundus photography of the observed area is made at the same time (Topcon camera DC1, resolution = 3.24 Mp). Results For posterior segment imaging, the flexible optical arrangement of the slit lamp and the hand-held lens (Volk), allows the user to scan large areas of the retina (>45 degrees), depending on the pupil size of the patient. In all patients the macula and optic disk could be visualized without any difficulty. In the anterior segment mode, the SLSCAN-1 allows imaging of the cornea, anterior chamber, iris and parts of the lens. Conclusion The images made by the SLSCAN-, new slit lamp integrated FD-OCT, could be very useful to examine patients directly, both posterior and anterior, during regular slit lamp examinations. Commercial interest [source] The taming of the shrew?ACTA OPHTHALMOLOGICA, Issue 5 2009The immunology of corneal transplantation Abstract. Corneal transplantation, first reported a century ago, is the oldest and most frequent form of solid tissue transplantation. Although keratoplasty is also considered as the most successful transplant procedure, several studies indicate that the long term survival of corneal grafts is even lower than that of transplanted parenchymatous organs. Despite the immune privilege enjoyed by the cornea and anterior segment of the eye, immunologic graft rejection is a major limitation to corneal transplantation. This review gives an update on corneal immunobiology and the mechanisms of corneal graft rejection, focusing on antigen presentation, as well as on the molecular and cellular mediators of this particular immune response. [source] The Beijing Eye StudyACTA OPHTHALMOLOGICA, Issue 3 2009Jost B. Jonas Abstract. Purpose:, This review presents and summarizes the findings of the Beijing Eye Study. Methods:, The Beijing Eye Study is a population-based study which included 4439 of 5324 subjects (aged , 40 years) who were initially examined in 2001. The study was repeated in 2006, when 3251 (73.2% of 4439, or 61.1% of 5324) of the original subjects participated. Participants underwent a series of examinations including: refractometry; pneumotonometry; biomicroscopy assisted by slit-lamp; optical coherence tomography of the anterior segment; photography of the cornea, lens, optic disc, macula and fundus; blood sampling for laboratory tests; blood pressure measurements, and determinations of anthropomorphic parameters. They were also asked to complete a questionnaire which included questions on socioeconomic parameters, and awareness and treatment of ocular and general diseases. Results:, We present normative data for refractive error, anterior segment measurements, intraocular pressure and optic disc structures and their associations, frequency and causes of visual impairment, blindness and visual field defects, prevalences of trachoma, pterygia, open-angle glaucoma and angle-closure glaucoma, cortical, nuclear and posterior subcapsular cataract, age-related macular degeneration, retinal vein occlusions, diabetes mellitus and diabetic retinopathy, myelinated nerve fibres, and retinitis pigmentosa, and associated and risk factors. Discussion:, These data may be helpful for dealing with public health issues in China and for assessing associated and risk factors of ocular and general diseases in general. [source] Longitudinal study of anterior segment inflammation by ultrasound biomicroscopy in patients with acute anterior uveitisACTA OPHTHALMOLOGICA, Issue 2 2009Yang Peizeng Abstract. Purpose:, This study aimed to investigate dynamic changes in the anterior segment in patients with acute anterior uveitis (AAU) using ultrasound biomicroscopy (UBM). Methods:, Acute anterior uveitis was diagnosed in 18 patients according to history and ocular examinations. Ultrasound biomicroscopy was performed and the results at three time-points (within 2 weeks of the uveitis attack, and at 2,4 weeks and 6 weeks after it) were analysed. The relationships between clinical manifestations and UBM findings were also evaluated. Results:, All investigated AAU patients showed severe ciliary injection, numerous dust keratic precipitates (KPs), aqueous flare and inflammatory cells, and were treated predominantly with corticosteroid and cycloplegic eyedrops. Ultrasound biomicroscopy showed a large number of cells in the anterior and posterior chamber, marked oedema and exudates in and around the iris and ciliary body within 2 weeks of AAU onset. These abnormalities were dramatically improved at 2,4 weeks and almost resolved at 6 weeks and thereafter. Conclusions:, Ultrasound biomicroscopy reveals severe inflammatory changes in and around the ciliary body in patients with AAU. These signs rapidly resolve upon treatment. [source] Ocular manifestations in liver transplant recipients with familial amyloid polyneuropathyACTA OPHTHALMOLOGICA, Issue 5 2008Ola Sandgren Abstract. Purpose:, To evaluate postoperative ocular involvement in Swedish liver transplant (LT) recipients with familial amyloid polyneuropathy (FAP). Methods:, Routine ophthalmological examinations were performed in 48 LT recipients, with particular attention given to amyloid deposition in the anterior segment and the vitreous body. Medical records were scrutinized for information regarding neurological impairment at the time of the LT. The diagnosis was secured in all cases by examining for amyloid deposits in biopsy specimens and positive genetic testing for amyloidogenic transthyretin (ATTR) Val30Met mutation. Results:, Six patients (12.5%) developed vitreous opacities within the post-LT observation period. The first opacities were seen 40 months after transplantation, 8 years after the onset of systemic disease. Four patients (8%) developed secondary glaucoma, the first of which was observed 18 months after the procedure and 6.5 years after the onset of disease. Sixteen patients (33%) developed deposits on the anterior surface of the lens. Scalloped pupillary margins were noted in 10 patients (21%). Conclusion:, The prevalence of eye complications increases with time after LT and regular follow-up is necessary, especially to disclose the development of glaucoma , a complication with insidious symptoms of which patients are normally unaware. [source] Is AZOOR an autoimmune disease?ACTA OPHTHALMOLOGICA, Issue 2007SF SEIDOVA Purpose: Acute zonal occult outer retinopathy (AZOOR) is one of the "white dot syndromes" a clinically heterogeneous group of inflammatory chorioretinopathies. The etiology is not yet clear. Methods: We present a 50 years female patient with a prior history of migraine. She experienced progressive visual loss and visual field defects in the last 3 years. Preceding each episode she experienced blue flickering photopsias. Results: Visual acuity was 0,3 in the right eye and 0,6 in the left eye. Biomicroscopy showed a normal anterior segment, fundus exam revealed pigment epithelial atrophy more pronounced in the worse eye. Electrophysiology showed a marked reduction in the photopic ERG in the more affected eye. MRI demonstrated multiple white matter lesions including a corpus callosum location. Lumbar puncture showed oligoclonal bands. Further tests demonstrated hearing impairment. Therapy was instituted during the three years course of the disease with steroids, immune suppressants and plasmapheresis with visual loss being progressive. New photopsia is currently present. Conclusions: The etiology of AZOOR remains unclear. With our patient being one of the few described in the literature with concomitant multiple sclerosis, the question remains on whether there is an underlying common process of inflammatory autoimmune reactions. Whether treatment is possible, remains to be evaluated. [source] Photography of the anterior eye segment according to Scheimpflug's principle: options and limitations , a reviewCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 1 2009Alfred Wegener PhD Abstract Scheimpflug photography and densitometric image analysis are very precise techniques for light scattering measurement and biometry in the anterior segment of the eye. They provide reproducible data on the characteristics of the anterior eye segment in clinical and experimental studies and the set of data obtained allows discrimination of light scattering changes because of ageing, disease or toxic effects. The techniques can also be used to determine no-effect levels or maximally tolerable dosages of physical and chemical noxious factors. Several Scheimpflug cameras have been marketed, but the only cameras commercially available today are the Nidek EAS 1000 and the Oculus Pentacam. This review outlines the development of the technique and its introduction into ophthalmology. Furthermore, the application of the technique in clinical and experimental ophthalmology as well as in ocular toxicology are presented and discussed. [source] Dexamethasone alters F-actin architecture and promotes cross-linked actin network formation in human trabecular meshwork tissueCYTOSKELETON, Issue 2 2005Abbot F. Clark Abstract Elevated intraocular pressure is an important risk factor for the development of glaucoma, a leading cause of irreversible blindness. This ocular hypertension is due to increased hydrodynamic resistance to the drainage of aqueous humor through specialized outflow tissues, including the trabecular meshwork (TM) and the endothelial lining of Schlemm's canal. We know that glucocorticoid therapy can cause increased outflow resistance and glaucoma in susceptible individuals, that the cytoskeleton helps regulate aqueous outflow resistance, and that glucocorticoid treatment alters the actin cytoskeleton of cultured TM cells. Our purpose was to characterize the actin cytoskeleton of cells in outflow pathway tissues in situ, to characterize changes in the cytoskeleton due to dexamethasone treatment in situ, and to compare these with changes observed in cell culture. Human ocular anterior segments were perfused with or without 10,7 M dexamethasone, and F-actin architecture was investigated by confocal laser scanning microscopy. We found that outflow pathway cells contained stress fibers, peripheral actin staining, and occasional actin "tangles." Dexamethasone treatment caused elevated IOP in several eyes and increased overall actin staining, with more actin tangles and the formation of cross-linked actin networks (CLANs). The actin architecture in TM tissues was remarkably similar to that seen in cultured TM cells. Although CLANs have been reported previously in cultured cells, this is the first report of CLANs in tissue. These cytoskeletal changes may be associated with increased aqueous humor outflow resistance after ocular glucocorticoid treatment. Cell Motil. Cytoskeleton 60:83,95, 2005. © 2004 Wiley-Liss, Inc. [source] Short and long germ segmentation: unanswered questions in the evolution of a developmental modeEVOLUTION AND DEVELOPMENT, Issue 6 2005Paul Z. Liu Summary The insect body plan is very well conserved, yet the developmental mechanisms of segmentation are surprisingly varied. Less evolutionarily derived insects undergo short germ segmentation where only the anterior segments are specified before gastrulation whereas the remaining posterior segments are formed during a later secondary growth phase. In contrast, derived long germ insects such as Drosophila specify their entire bodies essentially simultaneously. These fundamental embryological differences imply potentially divergent molecular patterning events. Numerous studies have focused on comparing the expression and function of the homologs of Drosophila segmentation genes between Drosophila and different short and long germ insects. Here we review these comparative data with special emphasis on understanding how short germ insects generate segments and how this ancestral mechanism may have been modified in derived long germ insects such as Drosophila. We break down the larger issue of short versus long germ segmentation into its component developmental problems and structure our discussion in order to highlight the unanswered questions in the evolution of insect segmentation. [source] Anterior eye tissue transmission for the radiation with the wavelength from eye safe regionLASER PHYSICS LETTERS, Issue 12 2005H. Jelínková Abstract Comparison of the eye tissue transmission for six laser radiations from visible up to mid-infrared region was done. The attenuation of the alexandrite (visible 0.75 µm), and Nd:YAP (near infrared 1.08 µm) laser radiations was found to be minimal , a retina reachs ,46% energy of these lasers entering the eye. On the other side the radiations of 1.54 µm (Er:glass), 1.66 µm (Er:YAP), and 2.01 µm (Tm:YAG) lasers are absorbed by the anterior segments of the eye and no impact is appeared on the retina. The absorption values measured for 1.34 µm (Nd:YAP) was recorded to be between the curves obtained for two groups of radiation wavelengths mentioned above. On retina, only 0.5% of the cornea radiation level was found. In this case the anterior parts of the eye are affected partially but not so deeply as in the case of eye safe radiation application. (© 2005 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source] | |||||||||||||