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Results for “Aqueous Humor”

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PubMed1996

Effects of endothelin A and B receptors on aqueous humor dynamics in the rabbit eye.

This study attempted to clarify the role of endothelin A and B (ETA and ETB) receptors in modulating aqueous humor dynamics in the rabbit eye. Intraocular pressure (IOP), aqueous flow, total outflow facility, and uveoscleral outflow were measured before, and 24 hours after, intravitreal injection (20 microliters) of a selective ETB agonist, sarafotoxin S6c (SRTX S6c, 10(-5) M), into one eye and its vehicle into the contralateral eye. The measurements were also performed before and after injection of a selective ETA antagonist, 97-139 (10(-2) M) + ET-1 (10(-5) M) into one eye, and vehicle + ET-1 (10(-5) M) into the contralateral eye. In the SRTX S6c-treated eye, total outflow facility increased significantly by 106% compared with that in the vehicle-treated eye 24 hours after injection; aqueous flow and uveoscleral outflow failed to change significantly. The ETA antagonist 97-139 inhibited the decrease in aqueous flow partially, but significantly, but failed to inhibit the increase in total outflow facility caused by ET-1. Therefore, both ETA and ETB play a significant role in modulating aqueous humor dynamics in the rabbit eye. ETA can modulate aqueous humor production, at least in part. ETB can modulate total outflow facility, and the possibility for ETB in modulating aqueous humor formation cannot be ruled out.

Animals↗

PubMed2004

Comparative penetration of moxifloxacin and gatifloxacin in rabbit aqueous humor after topical dosing.

PURPOSE: To evaluate the aqueous penetration of the fourth-generation fluoroquinolones moxifloxacin and gatifloxacin. SETTING: University of Arizona, Tucson, Arizona, USA. METHODS: Forty eyes of 20 New Zealand white rabbits were divided into 2 experimental groups. In Experiment I rabbits (20 eyes), a commercial preparation of topical gatifloxacin 0.3% was administered to 9 eyes and moxifloxacin 0.5% to 9 eyes; 2 eyes served as a control. Eyes were dosed according to a keratitis protocol; ie, every 15 minutes for 4 hours. The aqueous humor was sampled 10 minutes after the last dose. Experiment II rabbits (20 eyes) were dosed according to a cataract prophylaxis protocol; ie, 4 times a day for 10 days. The aqueous humor was sampled 1 hour after the last dose of antibiotic in 12 eyes and 24 hours after the last dose in 8 eyes. High-performance liquid chromatography was used to determine the fluoroquinolone concentration. RESULTS: In the keratitis dosing protocol, the mean concentration of moxifloxacin in the aqueous (n=9) was 11.057 microg/mL (range 7.66 to 18.87 microg/mL), which was significantly higher than the mean concentration of gatifloxacin (n=8) (7.570 microg/mL [range 4.75 to 10.86 microg/mL]) (P=.030). In the cataract prophylaxis dosing protocol, the mean aqueous concentration of moxifloxacin (n=6) was 1.745 microg/mL (range 0.92 to 3.87 mg/mL). The mean concentration of gatifloxacin (n=6) was 1.207 microg/mL (range 0.44 to 2.44 microg/mL). The difference was not statistically significant (P=.359). CONCLUSIONS: Higher mean levels (x1.46) of aqueous penetration were achieved with moxifloxacin than with gatifloxacin in the keratitis-dosing model. There was no statistically significant difference between the 2 drugs in the cataract prophylaxis dosing model. Both antibiotics had aqueous levels in excess of the minimum inhibitory concentration for most pathogenic organisms in both models.

Administration, Topical↗

PubMed1999

TGF-beta2 in aqueous humor suppresses S-phase entry in cultured corneal endothelial cells.

PURPOSE: Corneal endothelium in vivo is arrested in G1, the phase of the cell cycle that prepares cells for DNA synthesis. In many cell types, transforming factor (TGF)-beta inhibits proliferation by inducing G1-phase arrest. Evidence indicates that corneal endothelial cells synthesize mRNA for TGF-beta1 and are also bathed in aqueous humor that contains TGF-beta2 (mainly in a latent form). As such, this cytokine may maintain the corneal endothelium in a G1-phase-arrested state in vivo. The purpose of these studies was to determine the effect of exogenous TGF-beta2 and TGF-beta2 in aqueous humor on DNA synthesis in cultured corneal endothelial cells. METHODS: Rat corneal endothelial cells were grown in explant culture and identified by morphology and reverse transcription-polymerase chain reaction using primers for specific corneal cell markers. Subconfluent cells were synchronized in the G0 phase (quiescence) by serum starvation for 24 hours. Serum was then added to the cells in the presence or absence of exogenous TGF-beta2 or activated rat aqueous humor. [3H]Thymidine was added, and radioactivity was measured at various time points to detect DNA synthesis. Preincubation of exogenous TGF-beta2 or activated rat aqueous humor with neutralizing antibody was used to test for cytokine specificity. RESULTS: A linear increase in [3H]thymidine incorporation began approximately 16 hours after serum addition, and peak incorporation occurred at approximately 24 hours. Exposure of cells to serum plus TGF-beta2 suppressed [3H]thymidine incorporation in a dose-dependent manner at concentrations ranging from 5 pg/ml to 5 ng/ml. [3H]Thymidine incorporation was also suppressed in cells exposed to serum plus rat aqueous humor diluted 1:10. Neutralizing antibody reversed the effects of both exogenous TGF-beta2 and aqueous humor. CONCLUSIONS: Exogenous TGF-beta2 and TGF-beta2 in aqueous humor suppress S-phase entry of rat corneal endothelial cells. These results suggest that this cytokine in aqueous humor could help maintain the corneal endothelium in a G1-phase-arrested state in vivo.

Animals↗

PubMed2003

Proliferative diabetic retinopathy is associated with a low level of the natural ocular anti-angiogenic agent pigment epithelium-derived factor (PEDF) in aqueous humor. a pilot study.

Retinopathy is the most common microvascular diabetes complication and represents a major threat to the eyesight. The aim of this study was to address the role of pro- and anti-angiogenic molecules in diabetic retinopathy in the aqueous humor of the eye. Aqueous humor was collected at cataract surgery from 19 diabetic patients and from 13 age- and sex-matched normoglycemic controls. Levels of pro-angiogenic vascular endothelial growth factor (VEGF) and angiogenic inhibitor pigment epithelium-derived factor (PEDF) were determined. Angiogenic activity of the aqueous humor was quantified by measuring its effect on the migration of capillary endothelial cells. In the aqueous fluid, VEGF levels were increased in diabetics (mean values: 501 vs. 367 pg/ml; p = 0.05), compared to controls. PEDF was found to be decreased in diabetics (mean values: 2080 vs. 5780 ng/ml; p = 0.04) compared to controls. In seven diabetic patients with proliferative retinopathy, the most profound finding was a significant decrease of the PEDF level (mean value: 237 ng/ml), whereas VEGF levels were comparable to diabetic patients without proliferation (mean value: 3153; p = 0.003). Angiogenic activity in samples of patients from the control group was generally inhibitory due to PEDF, and inhibition was blocked by neutralizing antibodies to PEDF. Likewise, in diabetics without proliferation, angiogenic activity was also blocked by antibodies to PEDF. We will demonstrate here that the level of the natural ocular anti-angiogenic agent PEDF is inversely associated with proliferative retinopathy. PEDF is an important negative regulator of angiogenic activity of aqueous humor. Our data may have implications for the development of novel regimens for diabetic retinopathy.

Aged↗

PubMed1977

Penetration of topically administered prednisolone acetate into the human aqueous humor.

A single standardized drop of 1.0% prednisolone acetate labeled with tritiated thymidine was administered topically to one eye of 58 patients shortly before elective cataract extraction. An aqueous humor sample was aspirated at varying intervals and its corticosteroid content was determined. Peak drug concentration in aqueous humor was 1.13 mug/ml, which occurred 30 to 45 minutes after instillation of the medication. Substantial quantitites of corticosteroid were found in the aqueous humor five minutes after drug administration. The area under the drug concentration in aqueous humor-vs-time curve (a measure of the drug's bioavailability in aqueous humor) was 88 mug min/ml, and its half-life in human aqueous humor was 28 minutes. None of these values were significantly different from the comparable values in rabbit eyes.

Adult↗

PubMedDate not supplied

Penetration of levofloxacin into human aqueous humor.

This study was designed to measure the concentration of levofloxacin in aqueous humor after topical and oral administration in patients undergoing cataract extraction. Patients were randomly divided into four groups. Levofloxacin concentration in the aqueous humor was the highest in the group in which 600 mg was given orally plus five topical instillations before surgery. The aqueous humor levels of levofloxacin after topical and oral administration exceeded the minimum inhibitory concentrations for certain bacterial species that frequently cause intraocular infection.

Aged↗

PubMed2000

Levels of soluble ICAM-1 and soluble IL-2R in the serum and aqueous humor of uveitis patients.

PURPOSE: To study the ocular and systemic behaviour of the immune activation markers soluble ICAM-1 and soluble IL-2R in patients with active uveitis. METHODS: We determined the levels of soluble ICAM-1 and soluble IL-2R in the aqueous humor and peripheral blood of 23 patients with active uveitis and 16 age and gender matched controls (who were to undergo cataract extraction) by means of ELISA enzyme immunoanalysis. RESULTS: Patients with uveitis presented higher levels of soluble ICAM-1 and soluble IL-2R in the aqueous humor and peripheral blood. Comparison of the aqueous humor and peripheral blood revealed higher levels of soluble ICAM-1 in the aqueous humor, while we found no differences for soluble IL-2R. Analysis of the clinical characteristics of the uveitis we studied showed no differences in the levels of these markers in either blood or aqueous humor. CONCLUSIONS: The finding of elevated levels of soluble IL-2R and soluble ICAM-1 in the aqueous humor and peripheral blood of patients with uveitis suggests the local and systemic participation of these markers in the pathogenesis of uveitis.

Adult↗

PubMed2004

[Dynamic changes of tissue inhibitors of metalloproteinases in the rabbit iris and aqueous humor after lens mechanical injury].

OBJECTIVE: To investigate dynamic changes of expression of tissue inhibitors of metalloproteinases (TIMPs) in the rabbit iris and aqueous humor after the lens mechanical injury. METHODS: Rabbit lens was mechanically injured by a needle through the limbus. Eyes were enucleated on the 1st, 3rd, 7th and 15th day after injury, the aqueous humor was collected and the iris was isolated. The activity of two main TIMPs (TIMP-1 and TIMP-2) in the aqueous humor and the iris was assessed by reverse zymography assay while the activity of matrix metalloproteinase-2 (MMP-2) was analyzed by zymography assay. RESULTS: In the healthy and uninjured rabbit eye, neither TIMP-1 nor TIMP-2 was detected in the aqueous humor or in the iris. In the iris of the injured eye, the activity of TIMP-1 and TIMP-2 was increased significantly 1 day after the injury (P < 0.05), the activity of MMP-2 was inhibited. In the aqueous humor of the injured eye, the activity of TIMP-1 and -2 increased significantly (P < 0.05) 1 day after the injury and the activity of MMP-2 was not detectable. The activity of TIMP-1 and -2 decreased afterwards and no significant difference was detected between the injured eyes and the control eyes 7 days after the injury (P value was 0.097 and 0.777, respectively), while the activity of MMP-2 was increased gradually. CONCLUSION: TIMPs are involved in the acute inflammation process after the lens injury, which may play an important role in the inhibition of inflammation and in the wound healing.

Animals↗

PubMed1999

Prospective evaluation of external ocular microbial growth and aqueous humor contamination during cataract surgery.

PURPOSE: To analyze the route of aqueous humor contamination leading to the development of postoperative endophthalmitis. SETTING: Department of Ophthalmology, University of Helsinki, Finland. METHODS: Forty-nine eyes of 49 patients (31 having phacoemulsification and 18 extracapsular cataract extraction [ECCE]) participated in the study. Four bacterial cultures were taken: preoperative conjunctival swab, lid margin culture, intraoperative lacrimal lake sample, and immediate postoperative anterior chamber fluid sample. RESULTS: Preoperative lid margin cultures were positive in 59.2% of eyes, conjunctival cultures in 69.4%, and lacrimal lake cultures in 24.9%. Four aqueous humor samples (8.2%) showed bacterial growth in the anterior chamber aspirate: 3 in the phacoemulsification and 1 in the ECCE group. The bacteria isolated in this study, Staphylococcus epidermidis and Propionibacterium acnes (2 positive isolates each) were sensitive to the preoperative topical antibiotics used. No aqueous humor sample or any from other locations showed gram-negative microbe growth. The most frequently recovered microbes in all samples collected from the 3 other sources were S epidermidis and other coagulase-negative staphylococcus species, followed by P acnes and other propionibacterium species. Staphylococcus aureus, and diptheroids. CONCLUSION: The ocular surface significantly contributed to the transmission of microbes into the eye during cataract surgery. These microbes could not be eradicated by topical preoperative antibiotics. However, no patient developed postoperative endophthalmitis. Natural defense mechanisms appear to fend off a minor inoculum with these microbes of relatively low pathogenicity.

Anti-Bacterial Agents↗

PubMed1992

Study on the aqueous humor flow measured by fluorophotometry after argon laser trabeculoplasty.

We have investigated the variations in the aqueous humor flow (F) after argon laser photocoagulation (ALT) in the trabecular meshwork. The research has been done on 60 eyes with primary open angle glaucoma within initial stages. The argon laser trabeculoplasty was made around 360 degrees in anterior trabecular meshwork with 100 burns. The flow (F) has been studied by fluorophotometry using Yablonsky's protocol. Aqueous humor flow has been measured after 24 hours and after 7 days, to determine the immediate effects of laser trabeculoplasty; and also after 6 months for the long term effects. The initial aqueous humor flow was 1.35 microliters/min. By means of ANOVA we found statistically significant differences on aqueous humor flow after the 7th day (F = 1.67 microliters/min, p < 0.01), which remain six months later (F = 1.71 microliters/min, p < 0.01). This findings suggest that the effects of argon laser trabeculoplasty, either by mechanical or biological changes in the trabecular meshwork do not appear until the 7th day and remain throughout the follow up study.

Aged↗

PubMed1998

Evaluation of serotonin levels in human aqueous humor.

PURPOSE: Serotonin is biochemically present in the iris and ciliary body of animals and humans. Controversial findings are reported about the concentrations of serotonin in aqueous humor with respect to plasma in humans. The aim of this study was to evaluate the levels of serotonin both in aqueous humor and plasma in human subjects. METHODS: In 50 patients with glaucoma or cataract, plasma and aqueous humor serotonin levels were measured by HPLC with electrochemical detection. Serotonin plasma levels were also measured in 25 healthy subjects as controls. RESULTS: In all patients with cataract or glaucoma, the aqueous humor serotonin concentration is significantly lower than that in plasma [1.14+/-0.29 (SEM) vs. 5.33+/-1.03 ng/ml, p<0.01]. Furthermore, in the same patients and in 25 healthy controls, serotonin plasma levels were similar. CONCLUSION: Our study shows that serotonin is present in human aqueous humor and its concentration is 4 times lower than in plasma.

Adult↗

PubMed1981

Cephradine levels in human aqueous humor.

In an attempt to investigate penetration of cephradine into the primary aqueous humor in man, we administered 500-mg and 1-g doses of cephradine orally to 27 patients about to undergo elective cataract extraction. A mean peak aqueous humor level of 0.87 microgram/mL was obtained at about three hours after the 500-mg dose. The mean peak aqueous humor level after the 1-g dose also occurred at three hours and was 1.99 microgram/mL, with a range from 0.91 to 3.25 microgram/mL. This concentration was greater than the median minimum inhibitory concentration (MIC) of cephradine for Streptococcus pneumoniae, Str pyogenes, and Staphylococcus aureus (when tested in nutrient agar) but was greater than the MIC for 90% of isolates only with Str pyogenes.

Administration, Oral↗

PubMed1997

Immunologic and virologic characterization of the primary infiltrating cells in the aqueous humor of human T-cell leukemia virus type-1 uveitis. Accumulation of the human T-cell leukemia virus type-1-infected cells and constitutive expression of viral and interleukin-6 messenger ribonucleic acids.

PURPOSE: To characterize immunologically and virologically the infiltrating cells in the aqueous humor of patients with human T-cell leukemia virus type-1 (HTLV-1) uveitis (HU). METHODS: With their informed consent, patients had 0.1 ml of the aqueous humor in the anterior chamber collected with a needle under an operating microscope. An aliquot of the collected sample from patients without steroid therapy was examined by May-Giemsa staining and immunocytochemically. The presence of the HTLV-1-infected cells was investigated by polymerase chain reaction (PCR) using the gag and pol regions of the provirus genome. The population of the infected cells was compared by PCR testing the amplification of the virus genome from 60 cells, or determining the endpoint of successful amplification of the twofold dilution series of the samples, collected from the aqueous humor and peripheral blood mononuclear cells (PBMCs), which were obtained at the same time. Expression of viral and cytokine genes was studied by reverse transcriptase-PCR (RT-PCR). The interleukin-6 (IL-6) level in the aqueous humor of patients with HU and control subjects was measured by a high-sensitivity enzyme-linked immunosorbent assay kit. RESULTS: The number of the infiltrating cells ranged from 475 to 3563 (mean = 2111) per 0.1 ml of aqueous humor, and all the identifiable cells were lymphocytes. Most of them were CD3-positive T cells (mean = 78%), whereas CD4-positive cells constituted less than half (mean = 35.3%). HTLV-1 provirus was detected by PCR in the infiltrating cells of 36 of 38 patients with HU tested, whereas it was detected in 1 of 4 seropositive patients with other entities of uveitis. A higher population of the infected cells in the aqueous humor than in the PBMC was found in seven of nine patients with HU by two independent approaches. Expression of HTLV-1 env or pX genes or both was shown in all 12 patients with HU tested by RT-PCR. IL-6 messenger ribonucleic acid (mRNA) was detected by RT-PCR in 10 of these 12 patients, whereas those of interleukin-1 alpha, interleukin-2, interleukin-4, and tumor-necrosis factor-alpha were not, and that of interferon-gamma was detected in only 1 patient. The IL-6 level was elevated significantly in the aqueous humor of nine patients with HU compared with that of five control subjects (520.2 +/- 841 pg/ml versus 2.77 +/- 1.59 pg/ml, P < 0.01 by Mann-Whitney test). CONCLUSIONS: HU is characterized by lymphocytic infiltration with a predominance of T cells and by the presence and probable accumulation of HTLV-1-infected lymphocytes in the affected eye. Production of viral antigens and IL-6 by the infiltrating cells could be responsible for the development of HU.

Adult↗

PubMed1999

Effects of Tryptergium Wilfordii Polyglyco-sidium on the tumour necrosis factor levels in aqueous humor after intraocular lens implantation.

PURPOSE: Effects of Tryptergium Wilfordii Polyglyco-sidium (TWP) on the Tumour Necrosis Factor (TNF) levels in aqueous humor after intraocular lens (IOL) implantation were studied in rabbits. METHODS: Twenty-seven pigmented rabbits were divided into three groups. In the first group, the IOL were placed in the capsular bag after lens extraction. In the second group, rabbits received TWP therapy after IOL implantation. And in the third group, rabbit received prednisone therapy after IOL implantation. Aqueous humor samples were aspirated on the 1st, 3rd, 7th, and 14th postoperative day. A modified double antibodies indirect sandwich ELISA was used to detect for the presence of TNF. The data were closely studied by means of analysis of variance with SAS software. RESULTS: It was found that TNF level in aqueous humor reached its maximum on the 7th postoperative day in the group with IOL implantation. It was also found that the TNF levels in aqueous humor on the 7th and 14th postoperative day were significantly lower (P < 0.05) in the TWP-treated group with IOL implantation than those in the non-treatment group and the steroid-treated group. CONCLUSIONS: The current study offers evidence that TWP is more effective than the steroid in reducing the TNF level in aqueous humor after IOL implantation.

Animals↗

PubMed1984

Immunoglobulin levels in tears and aqueous humor of horses before and after diethylcarbamazine (DEC) therapy.

A quantitative investigation of equine tear and aqueous humor immunoglobulins was done using normal horses and ponies as well as horses and ponies infected with Onchocerca cervicalis. The equine immunoglobulin isotypes IgGa, IgM, IgA and IgG(T) were quantitated by either single radial immunodiffusion (SRID) or radioimmunoassay (RIA). Tear immunoglobulin levels for IgGa (128 +/- 151 micrograms/ml), IgA (1,664 +/- 1,038 micrograms/ml) and IgM (106 +/- 74 micrograms/ml) were measured, while IgG(T) was not detectable. In horses with ocular inflammation the IgGa was 18-fold higher in the tears, 2,269 +/- 3,077 micrograms/ml. Aqueous humor obtained by paracentesis of the normal equine eye under anaesthesia, resulted in values for IgGa (45.2 +/- 20.0 micrograms/ml), IgG(T) (5.2 +/- 2.0 micrograms/ml), IgM (1.3 +/- 4.8 micrograms/ml) and IgA (0.8 +/- 1.0 micrograms/ml). A pooled sample of normal aqueous fluid obtained from over 100 horses at an equine abbatoir in Indiana gave values of 1,150 micrograms/ml for IgGa, 65 micrograms/ml for IgG(T), 2.5 micrograms/ml for IgA and 3.0 micrograms/ml for IgM. In animals infected with 0. cervicalis and treated with Diethylcarbamazine (DEC), there was a marked elevation of IgGa and IgG(T) in the tears and aqueous humor while IgA and IgG(T) were also elevated slightly in the aqueous. The findings of elevated immunoglobulin isotypes in the aqueous humor may not be related to the DEC treatment and 0. cervicalis infections but rather to repeated paracentesis and the development of acute inflammation of the equine eye as a result of the trauma of paracentesis. The elevations in equine immunoglobulin isotypes in the tears after DEC treatment are not subject to the same caveat. The preferential elevation in IgGa and IgG(T) in the tears precedes the development of corneal opacities observed in the same horses. The concentration of specific antimicrofilarial antibody in these tears remains to be determined but may well account for a major share of the total immunoglobulins detected.

Animals↗

PubMed2000

Early aqueous humor analysis in patients with human ocular toxoplasmosis.

To evaluate the diagnostic sensitivity of a panel of laboratory tests for ocular toxoplasmosis performed at the time of presentation, paired samples of aqueous humor and serum were collected from 49 consecutive episodes of ocular toxoplasmosis with a clinical course of less than 3 weeks. Total immunoglobulin G (IgG) and Toxoplasma gondii-specific IgG, IgM, and IgA were quantified by enzyme-linked immunosorbent assay. The avidity of T. gondii-specific IgG was determined, and DNA extracted from aqueous humor was amplified for detection of a glycoprotein B gene sequence of T. gondii. The diagnosis was confirmed for 73% (36 of 49) of the patients; this rate rose to 79.5% if data from a later analysis of aqueous humor derived from five of the negative patients were included. The analysis of serum (detection of T. gondii-specific IgM and analysis of consecutive serum samples) alone did not contribute to the diagnosis. Calculation of local antibody production lacked diagnostic sensitivity when it was determined less than 3 weeks after the manifestation of clinical symptoms (28 of 49 patients [57%]), but this rose to 70% after an analysis of a second aqueous humor sample. The antibody avidity index attained diagnostic significance in only 8 of 43 instances (19%), and T. gondii DNA was amplified from no more than 6 of 39 (16%) aqueous humor samples. However, T. gondii-specific IgA was found within the aqueous humors of 11 of 43 patients (26%); measurement of the T. gondii-specific IgA level thus contributed substantially to the diagnostic sensitivity of the laboratory tests.

Animals↗

PubMed1997

Intracorneal, aqueous humor, and vitreous humor penetration of topical and oral ofloxacin.

OBJECTIVES: To investigate the intracorneal, aqueous, and vitreous penetration of ofloxacin, and to assess the concentration of the drug after topical administration alone and after combined topical and oral administration. METHODS: Twenty consecutive patients undergoing penetrating keratoplasty with vitrectomy for bullous keratopathy received 2 drops of 0.3% ofloxacin every 30 minutes starting 4 hours before surgery. Group A (10 patients) received topical therapy alone. Group B (10 patients) received an additional 3 doses of oral ofloxacin, 400 mg, every 12 hours starting 26 hours before surgery. Aqueous humor, vitreous humor, and corneal specimens were analyzed for ofloxacin levels. RESULTS: For group A, the mean intracorneal ofloxacin level was 4.51 micrograms/mL (range, 0.58-8.77 micrograms/mL; 10 specimens), the mean aqueous humor level was 1.34 micrograms/mL (range, 0.07-4.98 micrograms/mL; 8 specimens), and the mean vitreous humor level was 0.37 micrograms/mL (range, 0.05-0.90 micrograms/mL; 8 specimens). For group B, the mean intracorneal ofloxacin level was 8.59 micrograms/mL (range, 1.18-23.24 micrograms/mL; 10 specimens), the mean aqueous humor level was 2.77 micrograms/mL (range, 0.25-5.80 micrograms/mL; 10 specimens), and the mean vitreous humor level was 2.55 micrograms/mL (range, 0.28-4.97 micrograms/mL; 9 specimens). CONCLUSIONS: Topically applied ofloxacin achieves therapeutic levels in the cornea and aqueous. Mean levels achievable are well above the 90% minimal inhibitory concentration (MIC90) for the majority of bacteria responsible for endophthalmitis and corneal ulceration. The addition of oral ofloxacin to topical therapy increased vitreous penetration 7-fold in this assay trial.

Administration, Oral↗

PubMed2002

The effect of topical natural ergot alkaloids on the intraocular pressure and aqueous humor dynamics in rabbits with alpha-chymotrypsin-induced ocular hypertension.

BACKGROUND: We previously reported that topical natural ergot alkaloids ergocristine, alpha-ergocryptine and ergocornine dose-dependently reduce intraocular pressure in ocular normotensive rabbits, most likely by decreasing aqueous humor inflow. In the present study, the effects of these compounds on intraocular pressure and aqueous humor dynamics in a rabbit model for ocular hypertension were assessed. METHODS: Experiments were conducted in albino rabbits made ocular hypertensive by intracameral injection of alpha-chymotrypsin. Intraocular pressure responses to drug vehicle and seven different doses of topical natural ergot alkaloids were examined in order to obtain dose-response relationships for comparing the intraocular pressure-lowering effect and potency of these drugs. Tonographies were also performed to ascertain the actions of natural ergot alkaloids on aqueous humor dynamics in alpha-chymotrypsin-induced ocular hypertensive rabbits. RESULTS: Topical application of the natural ergot alkaloids ergocristine, alpha-ergocryptine and ergocornine lowered intraocular pressure in alpha-chymotrypsin-induced ocular hypertensive rabbits in a dose-related fashion, with ergocristine displaying the greatest intraocular pressure-lowering effect. Tonographic studies revealed a decrease in the tonographic outflow facility following topical application of natural ergot alkaloids, although only the effects of both ergocristine and alpha-ergocryptine reached statistical significance. All natural ergot alkaloids tested significantly reduced the calculated aqueous humor inflow. CONCLUSION: This study suggests that the natural ergot alkaloids ergocristine, alpha-ergocryptine and ergocornine effectively decrease intraocular pressure in the alpha-chymotrypsin-induced model of ocular hypertension. Since these compounds reduce the tonographic aqueous humor outflow facility, their final ocular antihypertensive effect appears to result from a remarkable reduction of the aqueous humor inflow.

Administration, Topical↗