bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ocular and plasma bioavailability of different memantine formulations after periocular administration
Authors: PRIETO CALVO E , BREGANTE UCEDO MA , PEREZ OLIVÁN S , PUENTE BAYO B 
Published: September 2009

Abstract Purpose To determine the memantine vitreous and plasma levels after the periocular injection of different types of memantine formulations, saline solution (SS), metylcellulose 0,5% (MC 0,5%) and polyvinylpyrrolidone 1% solution (PVP 1%); by posterior subtenon route. Methods In vivo experiments were done with albino New Zealand rabbits. Forty five rabbits were used and divided into 3 groups, one for each of the essayed formulations. 4,5 mg of memantine in 0,3 ml of formulation were administrated per animal by periocular injection into the posterior subtenon space, on the right eye of each animal. Plasma (2mL) and vitreous humor samples were obtained at 10, 60, 120, 240, and 1440 minutes post injection. A method with n‐hexane liquid‐liquid extraction and FMOC derivatization was used for the quantitative determination of memantine in the biological samples, using HPLC with fluorescence detection. Results Just 10 minutes post injection, detectable levels of memantine in plasma and vitreous humor were obtained on each of the 3 groups. Several concentrations of memantine were detected in vitreous from 10 to 1440 minutes when PVP formulation was administered. However, 24 hours post injection, no Memantine levels were detected on treated eyes with SS or MC 0,5% solution. According to plasma similar concentrations of memantine have been obtained for the different types of formulations. Conclusion After periocular administration, several memantine levels were detected in the vitreous chamber. In our opinion, these concentrations can be higher than after systemic and topic administration. The use of formulations as PVP, which has a higher permanence on the injected area, allows a sustained delivery of the drug.
The effect of betablockers on ocular hemodynamics in anesthetized rabbits
Authors: RUNGE CW , BOGNER B , STROHMAIER C , GRABNER G , REITSAMER HA 
Published: September 2009

Abstract Purpose To compare the effects of different betablockers on ocular hemodynamics in anesthetized New Zealand White rabbits. Methods Mean arterial pressure (MAP), intraocular pressure (IOP) and orbital venous pressure (OVP) were measured by direct cannulation of the central ear artery, the vitreous and the orbital venous sinus, respectively. Laser Doppler flowmetry was used to measure choroidal and ciliary blood flow. The performed measurements were made continuously at baseline and after drug application. Results Metoprolol showed a significant reduction of the choroideal blood flow (‐13,6 ± 1,4%, p = < 0,05) which was not observed in the ciliary body. Atenolol had a similar effect on the choroid with a significant reduction (‐7,3 ± 1,0%, p=< 0,05) and no significant change in the ciliary body. The intravenous administration of Nebivolol produced a decrease of the choroideal blood flow (‐11,2± 0,9%, p=< 0.05) and also no significant change of the ciliary blood flow. In all three series we could detect a clear decrease of IOP and heart rate. Conclusion All tested betablockers showed vasoconstrictive effects on the choroidea. Although they are different in their nature they showed similar effects by intravenous administration on the examined parameters. A vasodilative effect of nebivolol could not be detected.
Surgical experience and outcome of scleral buckling procedures in retinal detachment
Authors: ARNDT C , FRANCERIE‐SADDIKI V , BRUGNIART C , SEGAL A , DUCASSE A 
Published: September 2009

Abstract Purpose The purpose of this study was to evaluate the impact of the surgeons' experience on the anatomical and functional outcome of primary scleral buckling surgery in rhegmatogenous retinal detachment. Methods The charts of patients presenting with a retinal detachment between 2000 end 2006 were analyzed retrospectively. All patients with macular involvement treated with scleral buckling surgery were included. The surgeons were designated according to the “on call” list. Junior surgeons were fellows with less than 2 years of experience, physicians with more than 2 years of experience were defined as senior surgeons. Results Among the 115 included patients, 76 (65,8%) were operated by senior surgeons. The age, duration of symptoms, initial visual acuity, extension of the retinal detachment were similar in both groups. The primary reattachment rate was 87,7% in the senior surgeon group versus 92,1% in the junior surgeon group (p=0,36). In the eyes operated by senior surgeons, the final visual acuity was better than 20/40 in 78,5% versus 63,2% in eyes operated by junior surgeons (p=0,09).However, in phakic eyes with limited retinal detachments, the senior surgeons achieved better functional results (p<0.01). Conclusion The surgical experience, except in some subgroups of patients, did not significantly influence the anatomical or the functional overall outcome of patients undergoing primary scleral buckling surgery in retinal detachment with macular involvement.
First experience with The IRIS retinal implant system
Authors: VELIKAY‐PAREL M , IVASTINOVIC D , LANGMANN G , HORNIG R , GEORGI T , WEDRICH A 
Published: September 2009

Abstract Purpose To report on the first 4 months experience of a patient with the active IRIS‐ Implant. Methods 4 weeks after implantation the training with the active implant started. Thresholds were measured at each training day. Light perception, light localisation, point to point discrimination and motion detection were measured with special test procedures. Visual function training was performed. Results Visual perception was achieved, when the stimuli were generated by the computer and with the camera mode. All tests were successful. Conclusion Successful stimulation and major improvements during the training demonstrates that with the Iris Implant System a visual perception can be achieved, which is relevant for daily life.
Pre‐receptoral spectral absorption, healthy ageing and pre‐clinical indications of retinal disease
Authors: KONSTANTAKOPOULOU E , BARBUR J 
Published: September 2009

Abstract Purpose The aim of this study was to investigate how chromatic sensitivity changes as a function of age and to establish the extent to which such changes can be attributed to pre‐receptoral spectral absorption of short wavelength light and/or changes in retinal mechanisms caused by ageing. Methods The absorption of blue light by the macular pigment (MP) and the crystalline lens and the subjects’ sensitivity to rapid flicker were measured using the Macula Assessment Profile (MAP) test. Red‐green (RG) and yellow blue (YB) chromatic detection thresholds were measured at the fovea for young and older subjects using the Colour Assessment and Diagnosis (CAD) test at 2.6, 26 and 65 cd/m2. The variables of interest included the spectral absorption of the lens, the optical density of the MP, subject’s age and retinal illuminance. Results The absorption of blue light by the lens increased with age. Absorption of blue light by pre‐receptoral filters did not affect RG chromatic sensitivity at any of the light levels investigated but had an effect on YB thresholds. The considerably higher colour vision thresholds of some subjects and the subsequent worsening of their chromatic sensitivity at the lower light level may reflect changes in the retina brought about by accelerated aging effects. Conclusion The effect of pre‐receptoral absorption of blue light on chromatic sensitivity is small. Ageing affects the amount and spectral composition of the light reaching the photoreceptors and the processing of retinal signals. As a result, flicker sensitivity declines and colour vision deteriorates. Such effects arise mostly from changes in the retina. The MAP and CAD tests help us to detect the effects of accelerated ageing and retinal disease.
Detection of osmoprotective effect of topical compatible solutes on ocular surface epithelia
Authors: CALIENNO R , NUBILE M , LANZINI M , CURCIO C , COLESANTE M , CIAFRE M , MASTROPASQUA A 
Published: September 2009

Abstract Purpose Inflamation and hyperosmolarity play an important role in generating dry‐eye related damage on the ocular surface. A new approach is the use of topical compatible solutes (CS) to induce osmoprotective effect on ocular surface epithelia. Aim of this study was to evaluate the osmoprotective action of topical CS on ocular surface in dry‐eye patients. Methods We evaluated 48 eyes of 24 dry‐eye patients, current users of artificial tears. At baseline they underwent impression cytology (IC) and immunoflurescence staining to detect expression of inflammatory cytokines linked with hyperosmolarity in ocular surface epithelia. In vivo confocal microscopy (IVCM) of corneal and conjunctival surface was performed and epithelial morphology and inflammatory cells infiltration were evaluated. Patients started topical treatment with methilcellulose and CS in one randomly selected eye, while the fellow eye continued previous eye drops.IC and IVCM were performed after 30,60 and 90 days. Results At baseline IVCM and IC results were comparable in both eyes . At 90 days IVCM showed a significant improvement in epithelial regularity in treated eyes while in control group no significant changes were observed.IC evidenced a significant reduction of inflammatory cytokines between baseline time and day 60, stable till the end of follow‐up, while in control group no significant changes were observed. Conclusion The use of topical CS can improve epithelial regularity and reduce ocular surface inflammation in dry‐eye syndrome.
Loss of thioredoxin activity as an important contributor to oxidative stress in lens of diabetic rats
Authors: LOU M , LECHNER J , XING K , KADOR PF 
Published: September 2009

Abstract Purpose Thioredoxin (Trx) is a redox regulator whose bioavailability in mammalian tissues is regulated by its intrinsic binding protein, thioredoxin‐binding protein‐2 (TBP‐2). The purpose of this study is to investigate whether diabetic condition can alter the ratio of Trx and TBP‐2 expressions in the lens that may contribute to cataract formation. Methods Streptozotocin (STZ at 75 mg/kg) induced diabetic rats were divided into aldose reductase inhibitor (0.0125% AL1576) treated and untreated groups. Rats without STZ injection were used as controls. Lenses from 3 and 8 wks post STZ injection were used to determine GSH level, Trx activity, and Western blot analysis for Trx and TBP‐2 protein levels. Results The lenses in the diabetic untreated group showed slight haziness in 3 wks, and moderate to severe opacity in 8 wks while all lenses in the ARI‐treated or control groups remained clear in both ages. The untreated diabetic group showed severe loss in GSH (< 20% of control in both 3 and 8 wks) and Trx activity (< 35% of the control in both 3 and 8 wks). TBP‐2 expression although was unchanged at 3 wks but elevated ~4‐fold over the control in 8 wks while Trx expression remained constant at both time points. ARI treatment protected the GSH level, Trx activity, and TBP‐2 expression in these lenses. Conclusion Diabetic condition induced TBP‐2 expression in the lens with concurrent suppression of Trx activity. The results suggest that the loss of the bioavailability of TRx, in conjunction with a severe GSH depletion, is likely to contribute to the oxidative stress observed in diabetic conditions. Furthermore the observation that ARI can normalize these changes suggests a role of osmotic stress in Trx/TBP‐2 imbalance.
Treating diabetic dogs with topical KinostatTM for cataracts: proof of concept clinical trial
Authors: KADOR PF , ROBBIN‐WEBB T , BRAS D , KETERING KL , WYMAN M 
Published: September 2009

AbstractDiabetic dogs rapidly form bilateral sugar cataracts within one year of diagnosis. Similar sugar cataracts also form in galactose‐fed dogs. Since topical KinostatTM has been shown to reverse initial cataract formation in young galactose‐fed dogs, we have conducted a proof of concept masked pilot study with 41 newly diagnosed dogs with diabetes mellitus (DM) to investigate whether KinostatTM can inhibit the progression of cataracts in a clinical setting. After obtaining owner consent to participate in the study, all dogs were randomly assigned a coded vial containing either KinostatTM or vehicle for 1 year with the contents of the vial (drug or placebo) masked from the examiners. Thirty dogs received the active agent while the remainder received the placebo vehicle. Owners were instructed to administer the agent 3 times daily to both eyes and compliance was monitored by recording each time of administration. Ocular examinations on dilated eyes conducted at the initial examination and at 1, 2, 3, 6, and 9 month intervals with slit lamp and indirect ophthalmoscopy indicated that KinostatTM is beneficial in arresting the onset and/or progression of cataracts in dogs with DM. The implications of this study for human sugar cataracts will also be discussed. Supported by NIH SBIR 1R43EY018013‐01A1
Commercial interest
Anticataract effect as a predictor of drug efficacy against early diabetes‐induced retinal changes
Authors: OBROSOVA IG 
Published: September 2009

Abstract Purpose To evaluate if anticataract effect predicts drug efficacy against early diabetes‐induced retinal changes, using STZ‐diabetic rat model and cultured retinal microvascular cells. Methods Mature control and STZ‐diabetic rats received one of the following treatments (a prevention approach): 1) the aldose reductase inhibitor (ARI) fidarestat, 2) the PARP inhibitors, 1,5‐isoquinolinediol or GPI‐15427; 3) the Na+/H+‐exchanger‐1 (NHE‐1) inhibitor cariporide; and 4) two agents, counteracting endoplasmic reticulum stress,trimethylamine N‐oxide dehydrate or 4‐phenylbutyric acid. The duration of diabetes was 12 wks. Cataract formation was monitored by indirects ophthalmoscopy and slit lamp examination.Oxidative stress and apoptosis were assessed as early diabetes‐induced retinal changes in rat retinae and cultured bovine retinal pericytes and endothelial cells. Results An ARI treatment completely prevented cataract formation in STZ‐diabetic rats, whereas three other treatments delayed, but did not prevent, diabetes‐induced cataractogenesis. All four classes of agents counteracted diabetes‐induced apoptosis in rat retinae, and the ARI, PARP inhibitor, and NHE‐1 inhibitor treatments prevented high glucose and NEFA‐induced apoptosis in pericytes and endothelial cells. Fidarestat, PARP inhibitors, and cariporide treatments also counteracted diabetes‐related oxidative stress in the retinae and cultured retinal microvascular cells. The effect of agents counteracting endoplasmic reticulum stress on retinal oxidative stress has not been explored. Conclusion Anticataract effect ia a likely predictor of the efficacy of experimental pharmacological agents against, at least, early diabetes‐associated retinal changes which may facilitate diabetes drug discovery.
Commercial interest
Comparison of the visual response to corneal enhacement on femtosecond and microkeratome created flaps.
Authors: CANADAS SUAREZ P , IBARZ‐BARBERA M , HERNANDEZ ‐VERDEJO J , TEUS M 
Published: September 2009

Abstract Purpose To evaluate the evolution of visual acuity after enhacement after LASIK performed either with a mechanical microkeratome (MM) or femtosecond laser (FS), up to the third month post‐op. Methods Retrospective analysis of 148 consecutive eyes who had LASIK, 125 with femtosecond laser (intralase) and 123 with a mechanical microkeratome (Moria M2), had an enhacement performed between the third and the sixth month post‐op. All the surgeries were performed by the same surgeon. All the patients were examined preoperatively, 24 hours, 7 days, one month and three months after the enhancement. Results Both groups had good visual outcomes with no significant differences in visual acuity at the third month. The uncorrected visual acuity (UCVA) was 1.02±0.2 in both groups (p=0.9), the best corrected visual acuity (BCVA) was 1.07±0.1 and 1.09±0.1 for the FS and the MM groups respectively. The safety (1.02±0.1 in the FS group, 1.03±0.1 in the MM group, p=0.7) and efficacy (0.97±0.1 and 0.95±0.1 for the FS and MM respectively, p=0.4) were similar in both groups. Neverthelerss we found a statistically significant difference on UCVA on the first week (0.93±0.1 femtosecond vs 0.98±0.1 microkeratome, p=0.01). Conclusion Visual acuity recovery is slower after enhacement on FS flaps only on the early postoperative period. Probably, there is an increased epithelial damage or a superior inflammatory response due to a more difficult flap‐lifting in FS vs a MM cases.
Microplasmin improves surgical outcome in a rabbit model for trabeculectomy
Authors: VANDEWALLE E , VAN BERGEN T , YOU Y , VAN DE VEIRE S , MOONS L , STALMANS I 
Published: September 2009

Abstract Purpose This study was designed to study the efficacy and safety of Microplasmin as an anti‐scarring agent after trabeculectomy in a rabbit model. Methods The effect of Microplasmin was investigated in vivo in a rabbit model for glaucoma surgery. Clinical outcome measures were intra‐ocular pressure, bleb area and survival, side effects on slit lamp examination. Moreover, (immuno‐) histochemical analysis of the eyes was performed, with quantification of inflammation (CD 45) and collagen deposition (Trichrome and Sirius Red). In the first experiment (n=10), Microplasmin anterior chamber injection was compared to placebo injection. In the second experiment (n=3), topical Microplasmin drops were compared to placebo drops. In the third experiment (n=5) the combination of Microplasmin anterior chamber injection and topical drops was compared to placebo injection and drops. All experiments were conducted in a masked observator way. Results Microplasmin significantly augmented the bleb area and survival in a rabbit model of trabeculectomy after a single anterior chamber injection or combination therapy (injection combined with drops) compared to control. Collagen deposition was borderline reduced after Microplasmin administration compared to control. No significant changes in inflammation were noticed in the anterior chamber or in the conjunctiva. Conclusion Microplasmin single injection or combination with postoperative drops improved the outcome after trabeculectomy. In a rabbit model, larger blebs were produced for a longer period compared to control, and collagen deposition tended to decrease in this small series.
Do patients with normal tension glaucoma have a thinner conjunctiva?
Authors: VAN GINDERDEUREN R , STALMANS I , SPIELBERG L , ZEYEN T 
Published: September 2009

Abstract Purpose The central cornea is thinner in patients with normal tension glaucoma (NTG). We had developed the surgical impression of thinner conjunctivas in patients with NTG. The purpose of this study was to determine whether there is a difference between the conjunctival thickness of patients with NTG and those with high tension primary open‐angle glaucoma (POAG). Methods In this prospective study, 40 patients scheduled for trabeculectomy were categorized into NTG and POAG based on maximum intraocular pressure (IOP) as measured by Goldmann applanation tonometry. Ten (10) patients with NTG (max. IOP≤21mmHg) and 30 patients with high tension POAG (max IOP>21mmHg) were included in the study. Conjunctival biopsies taken from the inferior fornix one month prior to trabeculectomy were fixed in formalin and embedded in Historesin. The conjunctival thickness was measured on a standardised way and compared between the two groups. Non‐paired Student T test for two‐tailed groups with equal variance was used for statistical analysis. Results The difference in mean conjunctival thickness between patients with NTG (66.4μ±21.1) and patients with high tension POAG (104.6μ±44.3) was statistically significant (P=0.045). The mean CCT in NTG (537,6±19.6) was lower than in POAG (548.3±38.0), but did not reach significancy in this study. Conclusion Patients with NTG have a thinner conjunctiva than those with high tension POAG
Ocular neuromyotonia
Authors: BOSCHI A 
Published: September 2009

AbstractOcular Neuromyotonia (ONM) is rare disorder characterized by intermittent diplopia, lasting minutes or seconds, provoked by brief, episodic contraction of muscles supplied by the oculomotor, trochlear, or abducens nerve. These episodes are induced by change in the gaze direction or after holding eccentric gaze. Previous radiation therapy of the sellar or parasellar regions is the most frequent cause. Long standing compression of the oculomotor nerve, by tumor, supraclinoid aneurysms, arachnoiditis, basilar artery dolichoectasia, and others have been reported. Although the exact pathogenesis of ONM is still unknown, there is wide acceptance of the segmental demyelination hypothesis.This presentation will review the clinical presentation, discuss diagnosis work‐up as treatment options.
Visual fields after refractive surgery
Authors: DEMESTICHA A , GINIS H , KYMIONIS G , ASTIRAKAKIS N , PALLIKARIS IG 
Published: September 2009

Abstract Purpose Laser correction of ametropias is achieved by changing the radius of curvature of a central portion of the cornea. Although current refractive laser technology allows relative uniform correction across an optical zone larger than the scotopic pupil it must be kept in mind that centration of the ablation pattern pertains only to objects on the line of sight. Off‐axis objects are imaged not only through the corrected portion of the cornea but additionally through a meniscus of paracentral cornea involving the transition zone as well as untreated cornea. It was the purpose of this study to investigate the role of this optical effect in the peripheral visual fields in patients undergoing photorefractive keratectomy. Methods Twenty one eyes of thirteen patients were evaluated before and 3 months following PRK for the correction of myopia (average: ‐3.4D, SD:2.4D) at an optical zone of 6.5mm with the Allegretto 400 Excimer laser. Evaluation of the optical fields was made using the MEDMOND M700 visual fields analyzer using a full threshold procedure. Measurements were performed under cycloplegia while in all cases the subjects were corrected for the distance of the stimulus (+3 D) Results The detection threshold exhibited a decrease ranging from 0.5 to 9 dB (mean:1.5 dB, SD:2.5) for the periphery of the optical field (30 to 40 degrees). This change was statistically significant (p=0.00628). No statistically significant difference was observed for the central visual field (0‐22 degrees). Conclusion The loss of peripheral visual fields following refractive surgery may be attributed to the deteriorated retinal image quality in the peripheral visual field. A mathematical model of this reduction is proposed