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At least 811 records · Page 45Linked to original sources
PubMed1997

Simultaneous quantification of cefotaxime, desacetylcefotaxime, ofloxacine and ciprofloxacine in ocular aqueous humor and in plasma by high-performance liquid chromatography.

Cefotaxime, given intravenously, is currently used as a broad-spectrum antibiotic for prophylaxis of intra- and postoperative infections in ocular lens surgery. A proposed therapeutic and economic alternative is the use of orally active fluoroquinolone ofloxacine as prophylactic agent. A HPLC method was developed for determination of both antibiotics in ocular aqueous humor and plasma in order to optimize dosage for safe surpassing minimal inhibitory concentration in the humor compartment. For plasma determinations a solid-phase extraction procedure was used with ciprofloxacine as internal standard. Detection limits for direct HPLC-analysis of ocular aqueous humor was 0.08 microg/ml for all compounds, whereas in plasma 0.31 microg/ml could be determined after solid-phase extraction.

Anti-Bacterial Agents↗
PubMed1986

Unconventional aqueous humor outflow of microspheres perfused into the equine eye.

Normal drainage of aqueous humor from the anterior chamber of the equine eye occurred through conventional and unconventional routes. To determine the degree of uveoscleral outflow in the pony, 1- and 3-microns (diam) microspheres were perfused through the anterior chamber for 60 and 90 minutes. Two eyes were treated with pilocarpine before perfusion of spheres to observe any effect on outflow. Presence of spheres was detected by scanning electron microscopy and verified by light microscopy. By 60 minutes of the perfusion, 1- and 3-microns spheres thoroughly infiltrated the anterior uveal trabecular meshwork. The 3-microns spheres were notably excluded from the corneoscleral trabecular meshwork, whereas the 1-micron spheres packed into the corneoscleral trabecular meshwork and mixed with the angular aqueous plexus and intrascleral plexus vessels. After 90 minutes, 1- and 3-microns spheres penetrated the prominent supraciliary space and mixed with the suprachoroidea of the midchoroid. The 1-micron spheres infiltrated tissues more extensively than did the 3-microns spheres, packing into the anterior meshwork and supraciliary space and also moving as far posterior as the suprachoroidea of the peripapillary retina. Spheres also entered the iris, mostly at the root. Several 3-microns spheres moved into the interstitial spaces around axon bundles and vessels in the iris. The 1-micron spheres packed into these spaces in the iris root and were observed in the lumens of iris vessels. Single 1-micron spheres were observed in the lumens of choroidal vessels posteriorly. The present study supported evidence for uveoscleral and uveovortex flow in the horse and indicated that it may be more extensive than that in other species investigated (ie, the dog).

Animals↗
PubMed1986

[Diffusion of fosfomycin into the human and rabbit eye (aqueous humor and vitreous body)].

The intraocular distribution of fosfomycin was studied in 32 patients undergoing cataract surgery and in 8 rabbits after experimental infection of one eye by Staphylococcus aureus. Concentrations found 1 to 6 hours after termination of a 4 g fosfomycin infusion ranged from 14 to 18.8 mg/l in the aqueous humor and 8 to 12.5 mg/l in the vitreous body. These levels are higher than the MICs for 80 to 90% of the bacteria responsible for endophthalmitis. In each rabbit, the fosfomycin concentration in the infected eye as compared to the healthy eye was increased 2.5 to 5--fold for the aqueous humor and 4.9 to 19.2--fold for the vitreous body. Fosfomycin, in association with a third generation cephalosporin (ceftriaxone) or one of the new quinolones (pefloxacin) can be recommended for the prevention or early treatment of endophthalmitis.

Adolescent↗
PubMed1991

The effect of isosorbide-mononitrate eye drops on the human intraocular pressure and aqueous humor dynamics.

In a randomized, double-masked, single drop study the effect of topical isosorbid-mononitrate (ISMO) 0.5% eye drops, the main metabolite of isosorbid-dinitrate, widely used in the treatment of coronary heart diseases, was studied in patients suffering from open angle glaucoma or ocular hypertension. There was no statistically significant IOP change within 8 hours posttreatment after topical administration of ISMO 0.5%. There were no side effects after application of the ophthalmic solution of ISMO 0.5%. There were no significant changes in blood pressure and pulse rate either. A 2% ophthalmic solution of ISMO was investigated with respect to a response on the aqueous humor dynamics in 10 healthy volunteers. Anterior chamber fluorophotometry revealed a mean increase in aqueous flow of 39% within 3 hours after topical application (P less than 0.01). However, in comparison to the placebo treated fellow eyes there were no statistical significant difference in aqueous humor flow during the time of investigation. There was a statistical significant reduction of IOP during the same time period (p less than 0.03) in all treated eyes.

Aqueous Humor↗
PubMed1996

[T lymphocyte subsets in aqueous humor from patients with uveitis].

We studied T lymphocyte subsets in the aqueous humor (AH) and peripheral blood (PB) from patients with active uveitis using three-color flow cytometry. We assessed the number of T lymphocyte subsets that stained with fluorescence-conjugated anti-CD3, CD4, CD8, CD29, CD45RA, CD45RO, and HLA (human leukocyte antigen)-DR monoclonal antibodies in the AH and PB from 32 patients: 9 with sarcoidosis (SAR), 6 with Vogt-Koyanagi-Harade disease (VKH), 4 with HLA-B27+ uveitis, 2 with Behçet's disease, 2 with diabetic iritis, 9 with idiopathic uveitis, and 10 healthy control subjects. The percentage of CD3+ lymphocytes was significantly higher in uveitic AH than in PB. The percentage of CD4+ lymphocytes was significantly higher in uveitic AH than in PB in SAR. While the percentage of CD4+CD45RA+ (naive) cells within T cells was much lower in uveitic AH than in PB, the percentage of CD4+CD29+ or CD4+CD45RO+ (memory) cells was significantly higher. There was no significant difference in these subsets in PB between patients and controls. The results suggest that an increase in the number of activated memory T lymphocytes in AH is involved in the pathogenesis of uveitis.

Adult↗
PubMed2000

[Study on collagen viscoelastic substance as an auxiliary agent in anterior segment surgery--ocular irritation study by replacement of the aqueous humor in rabbits].

PURPOSE: Collagen solution was assessed as a possible viscoelastic substance in anterior segment surgery, in terms of the depth of the anterior chamber and ocular irritation. METHODS: The depth of the anterior chamber of enucleated rabbit eyes was evaluated 5 minutes after injection of collagen solution. For ocular irritation test, the aqueous humor of rabbits was replaced with collagen using sodium hyaluronate (HEALON) and phosphate buffer (PB) as controls. Follow-up clinical examinations with hand-slit-lamp-microscopy, tonometry, pachymetry, and specular microscopy were performed for 7 days or 28 days, and then aqueous humor, corneal endothelium, and eye tissues were evaluated by gel electrophoresis, scanning electron microscopy, and light microscopy, respectively. RESULTS: 2.5% to 3% collagen solution was found to be optimal for maintaining the depth of the anterior chamber. No significant differences in clinical findings such as anterior chamber and corneal thickness or in biochemical and histological findings were observed among collagen-, hyaluronate- and PB-treated groups, except for intraocular pressure which was increased in the hyaluronate-treated group, but not in the collagen-treated group. CONCLUSION: Collagen specifically prepared for this study seems to be an excellent auxiliary agent for anterior segment surgery, providing an appropriate anterior chamber with little ocular irritation.

Animals↗
PubMed1987

Tears and aqueous humor from horses inoculated with Leptospira contain antibodies which bind to cornea.

An antigenic relationship between Leptospira interrogans and equine cornea was previously described by us. An enzyme-linked immunosorbent assay was employed in the present work to investigate the existence of anti-leptospira and anti-cornea antibodies in tears, aqueous humor and serum from horses inoculated i.m. with those antigens. Ten days after a booster by the same route, antibodies that bind to microtiter plates, coated with an homogenate of either equine cornea or leptospira, were detected in those fluids and in the sera. At the same time, the corneas of the horses began to develop a diffuse opacity. This finding of anti-leptospira antibodies in equine tears and aqueous humor shows the pathway along which they arrive at the cornea and bind to it.

Animals↗
PubMed1983

The effect of topically administered carbonic anhydrase inhibitors on aqueous humor dynamics in rabbits.

Repeated topical administration of 2.5% trifluormethazolamide, a halogenated derivative of methazolamide, resulted in a unilateral decrease in intraocular pressure in rabbits. Mean (+/- S.E.M.) baseline intraocular pressure (19.8 +/- 2.1 mm Hg) was significantly (P less than .05) decreased 30 minutes (16.1 +/- 2.2 mm Hg) and 60 minutes (15.8 +/- 2.7 mm Hg) after drug administration. Trifluormethazolamide did not alter outflow facility. Aqueous humor flow calculated from the tonographic data was reduced 44% and flow measured by fluorophotometry was reduced 29%. Topical delivery of trifluormethazolamide decreased the level of carbon dioxide in the aqueous humor in the treated eye in a manner similar to that observed after systemic administration of carbonic anhydrase inhibitors. Topical administration of 10% acetazolamide did not decrease intraocular pressure. However, topical administration of either trifluormethazolamide or acetazolamide before oral administration of water resulted in a blunting of the water-induced ocular hypertensive response.

Acetazolamide↗
PubMed1992

[Interleukin-1 beta in the aqueous humor in aphakic and pseudophakic eyes of rabbits].

The amounts of interleukin-1 beta (IL-1 beta) (by enzyme linked immunosorbent assay (ELISA) using anti-rabbit recombinant IL-1 beta (rIL-1 beta) antibody) and total protein content (by Bradford's method) were assayed in the aphakic and pseudophakic aqueous humor in 24 eyes of 16 rabbits. Posterior chamber intraocular lenses were examined scanning electron microscopically and immunohistochemically. The amount of detected IL-1 beta was 10.79 +/- 4.67 ng/ml (mean +/- SD) in the pseudophakic eyes 3 days postoperatively, 10.12 +/- 3.96 ng/ml in the pseudophakic eyes and 3.94 +/- 0.86 ng/ml in the aphakic eyes 7 days postoperatively. A significantly higher amounts (p less than 0.001) of IL-1 beta were detected in the pseudophakic eyes compared with the aphakic eyes at 7 days postoperatively. The amount of IL-1 beta varied in each rabbit 1 month postoperatively. In total protein content in the aqueous humor, pseudophakic eyes showed significantly higher compared with the aphakic eyes at 7 days (pseudophakic eyes: 29.7 +/- 11.7 mg/ml, aphakic eyes: 8.58 +/- 6.90 mg/ml, p less than 0.05) and 1 month (pseudophakic eyes: 8.30 +/- 1.21 mg/ml, aphakic eyes: 2.10 +/- 0.309 mg/ml, p less than 0.001) postoperative. Scanning electron microscopic study showed that small round cells, spindle-shaped cells and giant cells could be observed on the surface of intraocular lenses. All of these types of cells showed positive staining of IL-1 beta immunohistochemically. These results suggest that IL-1 beta might be an inflammatory mediator in eyes with lens extraction, especially pseudophakic eyes.

Animals↗
PubMed2001

Increased levels of vascular endothelial growth factor and advanced glycation end products in aqueous humor of patients with diabetic retinopathy.

Clinical studies have shown a relationship between diabetic retinopathy and vascular endothelial growth factor (VEGF) levels in ocular fluid. Advanced glycation end products (AGEs) have been implicated in diabetes complications, including diabetic retinopathy. Nepsilon-(carboxymethyl) lysine (CML) is a glycoxidation product that may be a marker of oxidative stress. In this study, we used enzyme-linked immunosorbent assays to determine the levels of VEGF, non-CML AGE and CML in the aqueous humor and serum of 82 Japanese patients with type 2 diabetes and 60 non-diabetic subjects. VEGF, non-CML AGE, and CML concentrations in aqueous humor and serum were then compared with the severity of diabetic retinopathy. Immunohistochemical detection analysis of non-CML AGE and CML was also performed using retinal tissues from patients with progressive diabetic retinopathy. Aqueous levels of VEGF, non-CML AGE and CML increased along with the progression of diabetic retinopathy compared to age-matched controls. After coagulation therapy, the VEGF, non-CML AGE, and CML levels were significantly reduced. Immunostaining showed diffuse co-localization of non-CML AGE and CML around microvessels and in the glial cells of proliferative membranes from patients with progressive diabetic retinopathy. These findings suggest that glycation and glycoxidation reactions (or oxidation, as revealed by CML) may contribute to both the onset and progression of diabetic retinopathy.

Aged↗
PubMed1986

[Cytologic studies of the aqueous humor to determine immune reactions].

Although corneal grafting is performed on a so-called privileged (i.e., unvascularized) tissue, it is not always successful. Depending on the degree of vascularization of the host cornea (Stages I-IV) allograft reactions occur in 3 to 70% of patients thus treated. In an animal experiment (rabbits) a graft reaction was produced in the anterior chamber of one eye following presensitization with soluble corneal proteins, after implanting corneal tissue in the anterior chamber under the protection of a viscoelastic substance. The same grafting procedure was repeated on the fellow eye without previous sensitization. In the course of the immunoreaction the cell content of both eyes was studied and, 14 days after grafting, the result of aspiration cytology was compared with findings from light-microscopic examinations of the corneal graft and host cornea. A correlation was established between the results of aqueous humor cytology and the cytological findings in the corneal graft. It follows that immunoreactions can be interpreted reliably by aqueous humor aspiration cytology.

Animals↗
PubMed1989

HLA antigens in the iris and aqueous humor gamma interferon levels in anterior uveitis.

The induced expression of HLA antigens on a variety of tissues involved in autoimmune diseases has been reported by several groups. In this study, we have examined the expression of HLA antigens in iris biopsy specimens from patients with anterior uveitis and compared them to patients with noninflammatory senile cataracts. In addition, we measured the levels of gamma interferon in the aqueous humor of the same subjects. Our results show that there was induced expression of class I and class II HLA antigens in iris biopsies from patients with anterior uveitis and that the level of induced expression correlated with the concentration of gamma interferon found in the aqueous humor. These results suggest that induced expression of HLA antigens on iris cells may play a role in the pathogenesis of anterior uveitis and that gamma interferon may be one of the mediators for this induced expression.

Aged↗
PubMed2001

Acute effects of insulin on aqueous humor flow in patients with type 1 diabetes.

PURPOSE: Previous studies reported reduced aqueous humor flow through the anterior segment of the eye in patients with type 1 diabetes. This study investigates whether reduced flow is the result of the diabetic state or of alterations in glucose or insulin concentrations. METHODS: A cross-sectional study, involving patients with type 1 diabetes and healthy controls, measured aqueous flow at different insulin concentrations. Eleven patients with type 1 diabetes (hemoglobin A1C = 7.0 +/- 0.3% [mean +/- SEM], normal < 6.5) with no microvascular complications and 17 controls were prospectively studied. Controls were studied fasting and during a hyperinsulinemic-euglycemic clamp (insulin 2 mU/kg per minute). Patients with type 1 diabetes were similarly studied during two euglycemic clamp procedures (insulin 0.5 and 2.0 mU/kg per minute). Aqueous flow was measured by fluorophotometry. Pulsatile ocular blood flow and intraocular pressure were measured with a Langham flow probe. RESULTS: Control subjects had no change in aqueous flow during fasting and hyperinsulinemic conditions (3.0 +/- 0.1 vs 2.8 +/- 0.1 microl per minute). In the patients with type 1 diabetes, aqueous flow was not decreased with hyperinsulinemia, compared with the low insulin state (P =.7). Compared with control subjects, patients with type 1 diabetes had lower aqueous flow during hyperinsulinemia (2.4 +/- 0.1 microl per minute, P =.03) and at lower insulin conditions (2.6 +/- 0.1 microl per minute, P <.05). No differences in intraocular pressure or pulsatile ocular blood flow were noted between groups or between insulin states within groups. CONCLUSIONS: Aqueous flow is decreased in patients with type 1 diabetes under euglycemic conditions of high and relatively low insulin concentrations, despite the absence of microvascular complications.

Adult↗
PubMed1996

Arf 193nm excimer laser corneal surgery and photo-oxidation stress in aqueous humor and lens of rabbit: one-month follow-up.

Twenty male albino rabbits were studied. Four animals served as controls; the remaining 16 animals represented the treated group. All the treated animals were exposed to the same amount of energy delivered by the excimer laser (pulse rate: 20 Hz, fluence 250mJ/cm2; number of pulses: 6032; cumulative UV dose 1508 J/cm2) and were divided into eight groups of 2 animals each (four eyes). Samples of aqueous humor and lens were obtained at the following intervals: 5, 10, 20 and 40 min and 1, 2, 3 and 4 weeks after photorefractive keratectomy (PRK). The levels of reduced and oxidized glutathione, hydrogen peroxide, ascorbic acid and malondialdehyde were determined. Aqueous humor analyses, twenty min after PRK, showed no significant differences with pre-treatment values, while the observed variations in lens were constantly present over the entire follow-up period (one month). These findings suggest that the biochemical lens alterations induced by PRK may represent the earliest events relevant to cataractogenesis in the rabbit.

Animals↗
PubMed1993

[Hepatitis C virus in the aqueous humor].

Since a method for detecting hepatitis C virus (HCV) antibody has been established, many cases of non-A non-B sporadic and post-transfusion hepatitis are now known to have been caused by HCV. It is important to take steps against the nosocomial transmission of HCV as with the hepatitis B virus. Sera from patients in our ophthalmological clinic were tested for the presence of HCV antibody during the seven months from Oct. 1991 to Apr. 1992, utilizing C-100-3 antigen. We then searched for the presence of HCV in human aqueous humor among HCV antibody positive patients at the time of cataract surgery, utilizing the polymerase chain reaction (PCR) method. HCV antibody was found in 11 of 226 cases (4.9%); aqueous humor of six eyes from 5 of these cases tested with PCR showed negative results.

Adolescent↗