bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of a rat model of glaucoma induced by laser
Authors: BRON AM , SCHNEBELEN C , SALINAS‐NAVARRO M , ACAR N , PASQUIS B , CREUZOT‐GARCHER C , VIDAL‐SANZ M , BRETILLON L 
Published: October 2007

Abstract Purpose: To characterize a rat model on which glaucoma was induced by laser photocoagulation of episcleral veins, trabeculum and limbal veins. The characterization of the model was based on the evaluation of the intraocular pressure (IOP), the retinal function and the number of functional retinal ganglion cells (RGCs). Methods: Male Sprague Dawley rats were used at 6 weeks of age. Three of the episcleral veins, the trabeculum and the limbal veins were photocoagulated with a laser (532nm) in one eye. IOP (using a Tonolab®) and electroretinogram (ERG) were recorded every 2 weeks during 11 weeks. Three months after photocoagulation, RGCs were retrogradely labelled with a 5% Fluorogold solution applied to both superior colliculi. Seven days after labelling, retinas were flatmounted and were examined under a confocal fluorescence microscope equipped with a motorized stage. Functional RGCs were counted using an image analysis software (Image Pro Plus®). Results: Treated eyes displayed a significant increase in IOP as soon as the first week after the procedure (32 mmHg versus 18 mm Hg in control eyes) and lasting for 7 weeks. The retinal function of treated eyes was altered since the ERG b‐wave amplitude was significantly decreased when compared to control eyes (50% after 11 weeks). No differences were observed in the b‐wave latencies. A reduction of 50% of the number of RGCs was observed in treated eyes when compared to control eyes Conclusions: These results show that in the rat, eyes treated by laser photocoagulation are a valuable model of glaucoma since they display typical characteristics, namely elevated IOP, followed by an alteration of the inner retinal function and retinal ganglion cell death.
Evaluation of the performance of multifocal intraocular lenses image quality: analysis of the standard methods
Authors: MENEZO ROZALEN JL , ARTIGAS JM , FELIPE A , PERIS‐MARTINEZ C 
Published: October 2007

Abstract Purpose: To analyze the standard methods used to describe intraocular lenses (IOL) and to suggest some improvements to make them applicable for multifocal IOLs. Methods: The EN‐ISO standards and the standards of the American National Standards Institute (ANSI) for the evaluation of the performance of IOLs are tested for multifocal IOLs. The MTF of the one refractive multifocal IOL and two hybrid refractive‐diffractive multifocal IOLs is measured for both distance focus and near focus and using different pupil sizes. Results: The average modulation (AM) from 0 to 100 c/mm of multifocal IOLs (for the distance focus) is about 40‐50% lower than the AM of monofocal IOLs, for all pupil sizes studied. This fact suggests that the EN ISO standards must be revised in some points to be adapted for multifocal IOLs. Moreover, the near focus of the refractive IOL only appears beyond 3.5 mm of pupil size; in consequence this type of multifocal IOL could not be described only with a 3 mm pupil as stated in ISO standard.The width at half height of the point spread function (PSF) or the cut‐off frequency value of the MTF, are not useful for multifocal IOLs. Multifocal IOLs can have a narrow PSF at half height but be very wide at the bottom, occuring this even in some so‐called apodized IOLs. The cut‐off frequency value is also useful in monofocal lenses as quality factor to compare MTFs of different lenses or pupil sizes because an approximately uniform slope for the MTF is suppose. Conclusions: EN‐ISO and ANSI, demand the modulation of only one pupil and one frequency: 3 mm and 100 c/mm. We recommend to measure at least with 2 different pupils and to give the AM value for both distance and near focus.
The retinal vessel response to flicker light in patients with central retinal vein occlusion
Authors: REHAK M , REHAK J , LANGOVA K , WIEDEMANN P 
Published: October 2007

Abstract Purpose: The study examined the retinal vessel diameter (A/V Ratio) and the response to flicker light in patients with central retinal vein occlusion and in patients with arterial hypertension. Methods: The prospective study included 30 patients. In the group I. were 12 patients with central retinal vein occlusion (CRVO), in group II. 10 patients with hypertension and in group III. 8 healthy volunteers. A/V ratio (static analysis) and the diameter response of an arterial and venous vessel segment to flicker light (dynamic analysis) were measured with a Retinal Vessel Analyzer. Each dynamic examination consisted of a 50 s baseline measurement and three periods of 20‐s flicker light provocation followed by 80 s observation. The mean of three flicker cycles was calculated as dynamic vessel response. Results: Statistically significant differences of A/V ratio were observed in the static vessel analysis between groups I.‐III. (A/V ratio: 0.71±0.07; 0.76±0.06 and 0.82±0.02 respectively). The dynamic analysis showed statistically significant differences in arterial dilatation and constriction between all investigated groups as well. The venous flicker response showed significant differences between healthy controls (group III.) and group I. and II. No significant differences in venous response were measured between group I. and II. Conclusions: The results show significant differences in A/V ratio and arterial response to flicker stimulation in patients with CRVO. We suppose that the degree of retinal vessels endothelial dysfunction is one of the leading factors in the ethiopathology of central retinal vein occlusion.
Frozen fortified antibiotic in ophthalmic solutions stability during 2 months
Authors: MOURIAUX F , FINES‐GUYON M , CHEREL A , PERDRIEL A , ALBESSARD A , DEBRUYNE D , CHEDRU‐LEGROS V 
Published: October 2007

Abstract Purpose: Fortified antibiotic ophthalmic solutions are regularly administered as an immediate treatment for bacterial keratitis. The fortified antibiotics were used to be self‐prepared by nurses. To solve this problem, pharmacy staff studied the stability of three 5% solutions of vancomycin, amikacin and ceftazidim, prepared in aseptic conditions from parenteral antibiotic solutions. Methods: Solutions were frozen at ‐20°C. Portions of each solution were examined before storage and over a 75‐days period. Ceftazidim and amikacin were dilute in 0,9% sodium chloride and vancomycin in 5% dextrose. Over a 75 days period, physical, pharmacological (absorbance spectra) properties and sterility of each stock solution were studied. Results: The pH of amikacin (6,51), ceftazidim (6,47) and vancomycin (3,77) remained stable during the 75 days period. Osmolarities also remained stable (367, 488 and 351 mOsm/L). There were no significant differences in the concentration, osmolarity and pH of the three antibiotic solutions before storage and after 75 days of freezing. Over a 75 days period, stability of amikacin, ceftazidim and vancomycin remained constant; no contamination was detected before storage and after 75 days. Conclusions: Topical fortified antibiotic solutions can be stored 75 days at ‐20°C (15 days quarantine). After, these eye‐drops should be stored at 4°C and should be discarded after 3 days.
Functional characterisation of rats visual system following ocular ischemia by evoked potentials and retrograde transportation of retinal ganglion cells
Authors: JEHLE T , WINGERT K , DIMITRIU C , MESCHEDE W , LASSECK J , BACH M , LAGREZE W 
Published: October 2007

Abstract Purpose: The development of therapeutic strategies to protect cells following ischemia needs objective criteria for quantification of rats’ visual function. The present study demonstrate the impact of ocular ischemia on luminance and frequency modulated contrast vision and compare these with the function of the retinal cells and retrograde transportation of retinal ganglion cell staining. Methods: Ischemia was induced in adult Brown‐Norway rats by elevating the intraocular pressure to 120 mmHg for 30, 45, 60 and 90 min. The entire visual system was evaluated by visual evoked potentials (VEPs) modulated in luminance and frequency. The retinal function was analysed by scotopic and photopic electroretinogram (ERG). Vitality of RGC was investigated by stereotactic injection of FluoroGold into the superior colliculus for estimation of retrograde transport capacities four days after ischemia. Results: VEPs decreased depending on duration of ischemic episodes. The sensibility to ischemia was pronounced in higher frequencies. For ERG recordings, ischemia reduced oscillatory potentials and photopic flicker responses more intense than scotopic a‐ and b‐waves. RGC decreased from 2307±38 up to 36±58 (cells/mm2±SEM) and were significantly correlated with all electrophysiological parameters. The ischemic duration with 50% inhibition of responses was estimated for VEP between 36 to 58 min, for ERG between 36 to 41 min and was 51 min for RGC. Conclusions: Evoked potentials were sensitive indices for rat visual function after ocular ischemia. Understanding of these functional deficits may help to investigate neuroprotective strategies.
Retinal vein occlusion signals a significant risk of mortality in the Beijing eye study
Authors: LIBONDI T , XING L , LIU W , WANG Y , YANG H , JONAS JB 
Published: October 2007

Abstract Purpose: The purpose of the present population‐based investigation to assess whether retinal vein occlusion (RVO) may be associated with an increased mortality in the years following the event. Methods: The present investigation consisted of 8609 eyes (97.0%) of 4335 (97.7%) subjects for whom readable fundus photographs were available. For our study recent central retinal vein occlusion (CRVO) was characterized by the presence of retinal edema, optic disc hyperemia or edema, scattered superficial or deep hemorrhages, and venous dilatation. Old retinal vein occlusions were characterized by occluded and sheathed retinal veins. Results: Out of the 4335 subjects, 3194 (73.7%) subjects returned for follow‐up examination while 134 (3.1%) subjects were dead and 1005 (23.2%) subjects did not agree to be re‐examined or had moved away. In binary logistic regression analysis, mortality was significantly associated with age (P<0.001;95%CI:1.08,1.12) and RVO (P=0.047;95%CI:1.01,6.27). Including subjects with an age <70 years or <65 years, respectively, the association between RVO and mortality became further more significant (P=0.007; 95%CI:1.46,10.54; and P<0.001;95%CI:3.10,24.95, respectively). Conclusions: The results suggest that retinal vein occlusion, particularly in relatively young persons, may signal a significant risk of mortality. It confirms a recent combined evaluation of the Blue Mountain Study and the Beaver Dam Study in which, as in the present study on Chinese, patients with a retinal vein occlusion, particularly if the persons were younger than 69 years, had a significantly increased of mortality.
Intravitreal treatment with Erythropoietin (EPO) preserves visual function following ocular ischemia in rats
Authors: DERSCH R , JEHLE T , MESCHEDE W , DIMITRIU C , BACH M , LAGREZE W 
Published: October 2007

Abstract Purpose: Erythropoetin (EPO) is a promising neuroprotective drug. It is known that EPO reduces apoptosis of retinal ganglion cells following axotomy or glaucoma in rats. Until now, functional aspects of this neuroprotective effect have not been addressed. We investigated effects ofEPO on retinal and optic nerve function and on the survival of retinal ganglion cells following ocular ischemia. Methods: Ocular ischemia was induced by increase of the IOP to 120mmHg for 55 min in Brown‐Norway rats. Animals were treated intravitreally with 4U/eye (n=12) during the time of ischemia, controls (n=16) recieved BSS instead. Visual pathway was investigated by VEP 4 days after ischemia. Potentials were evoked by frequency and luminance modulated flicker stimuli and recorded in awake freely‐moving rats. Retinal function was evaluated by ERG 7 days after ischemia. Retinal ganglion cells were labelled retrogradelly 4 days after ischemia and were quantified 6 days later in retinal flatmounts. Results: Both frequency and luminance modulated evoked potentials increased due to the application of EPO from 6±2% (mean in percent of the non‐ischemic eye ± standard error) in control to 46±8% in treated animals and from 26±5% to 69±6% respectively. EPO increased responses of ischemic eyes from 31±6μV to 96±8μV (a‐wave) and from 34±6μV to 110±15μV (b‐wave). Morphologically, the intravitreal administration of EPO increased the number of surviving ganglion cells from 32±4% to 92±11%. Conclusions: We found a sizable functional benefit of intravitreal injection of EPO following interruption of ocular blood supply. This suggests that administration of EPO is a viable therapeutic option in ischemic retinal diseases.
Screening for diabetic retinopathy in a rural population with an itinerant non‐mydriatic camera
Authors: GARCHER CREUZOT C , BEYNAT J , ARNAVIELLE S , CHARLES A , ASTRUC K , BRON AM 
Published: October 2007

Abstract Purpose: The aim of this study was to evaluate the yield of diabetic retinopathy (DR) screening in a rural population with an itinerant non‐mydriatic camera. Methods: 1974 diabetics were screened between 2005 and 2006: 676 the first year and 1298 the second. The 72 lowest medicalised areas of Burgundy were visited. An orthoptist performed fundus photographies with a Topcon’s TRC‐NW200 non‐mydriatic camera (4 fields: posterior pole, nasal, temporal and upper). The photographies analysis was performed in the department of Ophthalmology, according to the International Clinical Diabetic Disease Severity Scale. The private ophthalmologists agreed to receive the positive or doubtful patients within one month. Results: On the 1974 screened patients, 103 presented a DR (5.2%), including 70 mild non‐proliferative DR (68%), 21 moderate non‐proliferative DR (20.4 %), and 12 severe non‐proliferative DR (11.6%). The rate of non interpretable photographies was 27.6%.The average age of the patients with a DR was 67.5 (27 to 94). The average onset of the diabetes was 16.5 years. Insulinic treatment was founded in 48 patients (46.6%) and 35 were aware of there HbA(1c) (34%) with an average of 7.8%. Lastly, 19 have had an ophthalmologic visit within one year before screening (18.4%), 38 between 1 and 2 years (36.9%), 28 more than 2 years (27.2%) and 10 more than 5 years (9.7%); 7 had never seen an ophthalmologist (6.8%). Conclusions: This screening improves the quality of the ocular follow‐up of the diabetics in rural area. The increase of the number of patients per meeting as well as a better recruitment would improve the medical and economic performances of the future campaigns.
Methylprednisolone (MP) failed to protect retinal ganglion cells and visual function following ocular ischemia in rats
Authors: DIMITRIU C , JEHLE T , MESCHEDE W , LASSECK J , BACH M , LAGREZE W 
Published: October 2007

Abstract Purpose: Methylprednisolone (MP) is commonly used to treat traumatic optic neuropathy and optic neuritis. It was neuroprotective in animal models of optic nerve crush, but showed negative effects after experimental autoimmune encephalitis. The present study investigated effects of MP on retinal ganglion cell (RGC) survival and on retinal and optic nerve function following ocular ischemia. Methods: Ocular ischemia was induced by increase in intraocular pressure to 120 mmHg for 55 min in adult Brown‐Norway rats. Animals were treated either with NaCl, 0.5 mg/kg MP or 15 mg/kg MP intraperitoneally direct after and every 12 hours for 3 days. RGCs were labelled retrogradelly 4 days after ischemia and were quantificated 6 days later. Retinal function was accessed by scotopic and photopic electroretinogram (ERG) 7 days after ischemia. The investigation of the visual pathways by frequency and luminance modulated visual evoked potentials (VEP) was performed in awake freely moving animals on day four and ten after ischemia. Results: Ocular ischemia lead to a decrease of labelled RGC to 47±3% when obtained NaCl (mean±SEM), 46±3% with 0.5 mg/kg MP and 43±6% with 15 mg/kg MP. ERG did neither differ significantly for scotopic a‐wave, b‐wave and oscillatory potentials nor for photopic 18 Hz flicker stimulation. Four days after ischemia the VEPs of rats receiving MP (0.5 and 15 mg/kg) were significantly higher compared to control. Ten days after ischemia potentials in both steroid groups decreased to control level. Conclusions: In our experiments treatment with MP did neither improve RGC survival nor retinal function. The delayed decrease of VEP indicated only a temporal benefit due to steroids.
Comparison of DCT, GAT and ORA values in patients with glaucoma
Authors: BREDOW L , LAUTEBACH S , HERDENER S , REINHARD T , PACHE M 
Published: October 2007

Abstract Purpose: The Ocular Response Analyser (ORA) is a novel device for the measurement of intraocular pressure (IOP), corneal hysteresis (CH) and the corneal resistance factor (CRF). We compared the ORA with Dynamic Contour Tonometry (DCT) and Goldmann Applanation Tonometry (GAT). Methods: We examined 63 eyes of 63 glaucoma patients (primary open angle glaucoma (POAG) n=26, normal tension glaucoma (NTG) n=10, ocular hypertension (OHT) n=15, pseudoexfoliation glaucoma (PEXG) n=12). After assessment of corneal thickness (CCT) by Orbscan, IOP was measured in a randomized order with the ORA, DCT and GAT. For each device mean IOP and for the ORA mean IOP, CH and CRF were calculated and assessed for potential dependency on CCT. Results: Mean IOP in mmHg was 20.6 (±6.1 SD) for the ORA, 18.2 (±4.2 SD) for DCT and 16.5 (±4.4 SD) for GAT. Bland‐Altman‐Analysis showed a good agreement between DCT and GAT, while the ORA showed a tendency to higher values in patients with higher IOP. None of the devices showed a dependency on CCT (GAT: r²=0.12, DCT: r²=0.07, ORA: r²=0.08). There was no correlation between CH and CCT (r²=0.01), but a weak correlation between CRF and CCT (r²=0.2). Patients with NTG had a significantly (p=0.005) thinner CCT (506±55μm) than patients with POAG (567±53μm). As could be expected, OHT‐patients showed higher CCT values (592±41μm). CRF was significantly higher in the OHT (11.6±2.2) than in the POAG group (9.6±2.0) (p=0.006). For CH, we observed no difference between groups. Conclusions: The ORA showed a good agreement with DCT and GAT for “normal” IOP, but we observed higher results compared to the other methods for high IOP‐values. We observed no correlation between CCT and IOP, but a weak positive correlation between CRF and CCT.
Corneoscleral transplantation for extensive infection of the cornea
Authors: FRESINA M , CELLINI M , LEONETTI P , BENDO E , CAMPOS EC 
Published: October 2007

Abstract Purpose: Corneoscleral grafts have been used in the past for anterior segment reconstruction after extensive infection of the cornea. The aim of this study is to present the results of a series of ten consecutive anterior segment reconstruction using corneaoscleral grafts. Methods: We studied ten patients with widespread corneal infection and coagulative necrosis of the cornea. Common features of the surgical technique included a total limbal peritomy in an endeavor to save possible limbal stem cells. To mark the scleral surface and partially trephine this tissue we used trephines of 14‐15 mm. After a careful haemostasis we entered the anterior chamber with a diamond knife. The entire cornea was removed and the donor corneoscleral graft was sutured into place onto the scleral ledge using interrupted 8.0 silk or 9.0 nylon sutures. The anterior chamber was filled with viscoelastic material and the conjunctiva was then closet to cover the peripheral part of the graft. Postoperative steroid therapy was methylprednisolone (1gr/kg of body weight) and betametasone 1% eye drops every two hours for 4 weeks and then every four‐hour for long term. Results: After a mean time of 15 months after corneoscleral grafts four patients maintain a clear graft. Six patients could be defined as having typical rejection episodes with the corneas becoming opaque Conclusions: The technique of corneaoscleral transplantation can salvage otherwise end stage eye disease, but the results are poor with respect to maintenance of vision. These patients need careful follow up because of potential complications especially graft rejection and recurrence of disease.
Safety limits estimation for ultraviolet radiation induced cataract in different age groups
Authors: DONG X 
Published: October 2007

Abstract Purpose: To investigate the effect of age on ultraviolet radiation induced cataract and establish the safety limits for different ages (rats and mice). Methods: A total of 80 female Sprague‐Dawley rats were included in four age‐groups: 3, 6, 10 and 18 weeks, and of 100 female C53 mice were included in four age‐groups: 3, 6, 12 and 24 weeks. Each age group was divided into 5 subgroups with different UVR exposure doses. The animal were unilaterally exposed to ultraviolet radiation (lmax=300 nm, l0.5= 10 nm ). The incident dose on the cornea was 0 ~ 8 kJ/m2. The animal were sacrificed and both lenses were extracted one week after exposure, the intensity of forward light scattering were measured and photographs were taken. The safety limit for ultraviolet radiation induced cataract for different age groups was estimated by the maximum tolerable dose, which based on the dose‐response function of different age groups. Results: Maximum tolerable dose for 3, 6, 10 and 18 weeks old rats was estimated to 1.4, 2.0, 3.8 and 4.6 kJ/m2 respectively, for mice of 3, 6, 12 and 24 weeks was 2.0, 3.2, 4.1 and 5.2 kJ/m2 respectively. Conclusions: Young animals were more sensitive to UVR than old ones, the age‐dependent trend hold the same for rats and mice. Age should be considered when estimating the risk for UVR induced cataract.
Correlation between ocular response analyzer (ora) and dynamic contour tonometer (pdct) parameters in normal subjects and in glaucoma patients
Authors: EHONGO A , DE MAERTELAER V , COLLIGNON N , POURJAVAN S 
Published: October 2007

Abstract Purpose: The ORA measures corneal biomechanical properties: CH and CRF. The PDCT measures OPA, the systolo‐diastolic variation of IOP. Both ORA and OPA values are lower in glaucoma than normal patients. Our purpose is to assess if there is a correlation between ORA and OPA values, and to compare these values between normal and glaucoma patients. Methods: 40 adult healthy volunteers (group1: G1) and 42 glaucoma patients (group2: G2) underwent prospectively consecutive 4 ORA, 3 OPA and 2 GAT measurements. Patients with previous refractive or intra‐ocular surgery, contact lenses were excluded for both groups. Also, patients with ocular eye disease, topical or general medications were excluded for G1.For each device, the mean of the measurements for one randomised eye in G1 and for the more affected eye in G2 was used for statistical analysis. Pearson correlations were used. Comparisons of the two groups mean values were made with a two‐tailed Student’s t test. Results: 82 eyes of 82 patients. The mean age for G1 and G2 was respectively: 43.6±14.6 and 65,1±13,6 years. The mean IOP was higher in G2 ( p <0.001) for the 3 devices, with no difference in CCT. CH ( p <0.001) and CRF ( p= 0,028) values were lower in G2. OPA was higher in G2 ( p =0,014). The OPA/CH and OPA/CRF Pearson correlations were respectively: r=0,079, p =0,627 and r=0,258, p =0,108 for G1, and r=‐0,116 p =0,463 and r=0,180 p =0,253 for G2. Conclusions: We did not find any statistical significant correlation between corneal biomechanical properties and the OPA values either in normal or in glaucoma group. We found lower corneal biomechanical properties in glaucoma than in normal group.