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Results for “Aqueous Humor”

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PubMed1996

[Tissue plasminogen activator and plasminogen activator inhibitor in aqueous humor].

BACKGROUND: In the anterior segment of the eye, fibrin clots must be rapidly resorbed to prevent fibrosis. Tissue-type plasminogen activator (t-PA), a serine protease that catalyzes the conversion from plasminogen to plasmin, plays an important role in the fibrinolytic system and has therefore in recent years attracted attention in the field of ophthalmology. MATERIAL AND METHODS: The aqueous humor of patients undergoing cataract surgery was analyzed for the presence of components of the fibrinolytic cascade. The quantities of t-PA and plasminogen-activator inhibitor (PAI) were determined using enzyme-linked immunosorbent assays. We determined t-PA and PAI in the aqueous humor of 64 patients between 59 and 82 years of age. RESULTS: The t-PA levels ranged from 0.65 to 1.75 ng/ml and PAI activity from 3.24 to 5.1 AU/ml. Association between t-PA levels and PAI activity and accompanying diseases or metabolic disorders was noted. The highest concentration of t-PA and the lowest activity of PAI has been observed in aqueous humor of patients with senile cataract. The knowledge about the presence of t-PA in aqueous humor is significant for the recognition of pathological events following intraocular fibrin formation and may be an important basis for therapeutic use of t-PA.

Aged↗

PubMed2003

Analysis of an anti-inflammatory steroidal drug, difluprednate, in aqueous humor by combination of semi-micro HPLC and column switching method.

A specific and sensitive method for the determination for difluprednate (DFBA) and its metabolite (deacetylated DFBA, DFB) in aqueous humor was developed. DFBA and DFB were initially absorbed on a Pinkerton-type column, then analyzed by high-performance liquid chromatography using a semi-micro column after column switching. Under the optimized conditions, calibration curves for DFBA and DFB showed good linearity over the range of 1.0-50 and 0.5-50 ng/ml, respectively. We applied the method to the analysis of DFBA and DFB in rabbit aqueous humor, and found that DFBA in rabbit aqueous humor 1 h after instillation of 0.002% DFBA ophthalmic emulsion was not detected, but DFB was present at the concentration of 4.3+/-3.1 ng/ml.

Animals↗

PubMed1984

Aqueous humor flow during sleep.

The rate of aqueous humor flow of 19 normal subjects was measured by a fluorescein clearance technique during the day, during sleep (at night) and during sleep deprivation (at night). Subjects engaged in routine activities during the daytime measurements and slept in comfortable quarters during the nighttime measurement. They remained awake and active during the sleep deprivation study. The nomographic method of Coakes and Brubaker , a method in which the subject is not disturbed at all during the critical 5-hr period, was used to calculate flow. Flow was lower during sleep in all but one subject. The range of nighttime flow suppression was 8% to 68% in all of the other subjects with a mean suppression of 45% +/- 20%. Aqueous flow was lower at night even when the subjects were awake but was lowest during sleep at night. The reduction of aqueous flow during sleep is comparable with the suppression that can be achieved with carbonic anhydrase inhibitors or beta adrenergic blockers.

Adult↗

PubMed1992

[Infiltration into the aqueous humor (uveitis) in a patient with malignant lymphoma].

An 80-year-old male was admitted to our hospital because of multiple tumors in October 1989. A pathological diagnosis of non-Hodgkin's lymphoma (diffuse, medium-sized cell type) was made with the histological examination of his biopsied tumors. His clinical stage was stage IV A. Chemotherapy (CHOP) brought him to complete remission. In May 1990, relapse of non-Hodgkin's lymphoma was observed in the neck and both eyes. The diagnosis of uveitis due to involvement of lymphoma cells was confirmed by an aspiration biopsy of left aqueous humor. Complete recovery of his visual acuity was possible with additional chemotherapy, and lymphoma cells in his right aqueous humor were expelled completely, while his cervical tumor remained 1/3 of the original size. He eventually died of pneumonia on December 9th, 1990. Intraocular involvement of malignant lymphoma is rare in comparison with extraocular involvement. Especially, the patient who has only turbid aqueous humor as an ophthalmic sign is very rare. In this paper, we reported a case of lymphoma with intraocular involvement and discussed the mechanisms of infiltration of lymphoma cells into the aqueous humor and the therapy.

Aged↗

PubMed2002

Detection of CMV in plasma and aqueous humor specimens from AIDS patients with CMV retinitis using the amplicor CMV test.

A DNA hybridization test (the Amplicor CMV test) for CMV DNA was used to detect CMV DNA in paired plasma and aqueous humor specimens from 37 AIDS patients with ophthalmoscopically diagnosed CMV retinitis. CMV was detected in 25/37 (67.6%) plasma specimens and in 32/37 (86.5%) aqueous humor specimens. Thus, the Amplicor CMV test using aqueous humor specimens seems to be a useful diagnostic test for CMV retinitis and one that is more sensitive than determination of CMV DNA in plasma specimens.

AIDS-Related Opportunistic Infections↗

PubMed1985

Aqueous humor dynamics in the owl monkey with comparison to cynomolgus.

The owl monkey is used in experimental ocular studies, but little data are available regarding its aqueous humor dynamics. We determined aqueous humor flow rate (AHF), anterior chamber elimination coefficient (Ke), and corneal endothelial transfer coefficient (Ka) fluorophotometrically; total outflow facility (C) by 2-level constant pressure perfusion; and the facility response to intravenous and intracameral pilocarpine in pentobarbital anesthetized owl monkeys. Baseline values (mean +/- S.E.M., n eyes) were: AHF = 1.52 +/- 0.14 microliter X min-1, n = 24; Ke = 6.54 +/- 0.65 min-1 X 10(-3), n = 24; Ka = 3.84 +/- 0.40 min-1 X 10(-3), n = 24; C = 0.35 +/- 0.03 microliter X min-1 X mm Hg-1, n = 26. Intracameral pilocarpine caused a dose-dependent facility increase, with the maximum response (a tripling of resting facility) occurring between 20 and 100 micrograms; intravenous pilocarpine, 2 mg/kg, also doubled to tripled facility. With certain qualifications, these findings are comparable to those in other primate species and confirm the usefulness of the owl monkey in carefully chosen experimental studies of aqueous dynamics.

Animals↗

PubMed1983

Glutathione in calf trabecular meshwork and its relation to aqueous humor outflow facility.

Previous studies have shown that sulfhydryl reagents can alter the facility of aqueous humor outflow but little is known about the sulfhydryl constituents of the aqueous outflow system or the effect of oxidants upon outflow facility. In the present study the concentration of glutathione (GSH) was measured in excised calf trabecular meshwork (TM) and found to be 0.40 mu mol/g wet wt (0.027 mu mol/mg protein). Oxidized glutathione was not detectable in the tissue. TM was found to have significant hexose monophosphate shunt activity as determined by measurement of the oxidation of 14C-1 and 14C-6-labeled glucose in tissue homogenates. The concentration of GSH in TM of enucleated calf eyes could be totally depleted by infusion of medium containing both diamide, which is an oxidant of GSH, and 1,3bis(2-chlorethyl)-1-nitrosourea (BCNU), which is an inhibitor of the enzyme glutathione reductase. The depletion of GSH was found to have no effect on the facility of aqueous outflow. Experiments were also done in which normal and TM GSH-depleted eyes were perfused with medium containing H202. Exposure to H202 produced no effect on outflow facility in the normal eyes but caused a 33% decrease in facility in eyes with the GSH-depleted TM. The results indicate that GSH may not participate directly in regulating aqueous humor outflow but is able to protect TM against H202-induced oxidative damage that would otherwise lead to a decrease in outflow facility.

Amino Acids↗

PubMed1998

Effect of mitomycin C on aqueous humor flow, flare and intraocular pressure in eyes with glaucoma 2 years after trabeculectomy.

BACKGROUND: The purpose of this study was to determine the intraocular pressure (IOP), aqueous humor flow, flare and ocular side effects in eyes with a history of hypotony after trabeculectomy with adjunctive mitomycin C (MMC). METHODS: Thirty-six eyes with primary or secondary open-angle glaucoma and IOP < or = 8 mmHg during the postoperative period were studied 745 +/- 315 days after surgery. MMC (0.2 or 0.5 mg/ml) was applied to the episclera with a cellular sponge. Flare was studied with the Kowa Laser Flare Meter 500. Aqueous humor flow was measured in the afternoon (Fluorotron Master II). IOP, visual fields and best corrected visual acuity were also examined. Twenty-two contralateral eyes without surgical intervention served as controls. RESULTS: The mean age of patients was 44.5 +/- 16.8 years. The mean IOP was significantly lower in the MMC group than in the control group: 9.6 +/- 6.4 mmHg vs 18.0 +/- 13.6 mmHg at 2 years (P < 0.001). Aqueous flow was significantly lower in subjects treated with MMC than in controls (P < 0.001). The flare values were significantly higher in the MMC-treated group, with a mean of 12.0 +/- 7.7 photon counts/ms, than in the control group, mean 7.9 +/- 4.6 photon counts/ms (P < 0.019). CONCLUSION: Our data suggest that MMC is a useful ocular hypotensive agent which seems to participate in a change in aqueous humor dynamics when applied topically as an aqueous solution.

Adolescent↗

PubMed1988

Amino acid concentrations in serum and aqueous humor from subjects with extreme myopia or senile cataract.

With an amino acid analyzer, we measured amino acids and related compounds in serum and aqueous humor from normal Chinese and some patients with extreme myopia or senile cataracts. Forty peaks were well resolved, and their areas were used to quantify each compound. In the myopic patients, glutamate, alpha-aminoadipate, and methionine concentrations in serum were 10-fold those in the normal subjects. Values for most of the other amino acids and related compounds were also higher in myopic patients' sera. In the cataract patients, concentrations of most of these compounds were lower in serum but higher in aqueous humor than for the normal subjects. Tryptophan was present in significant amounts in sera from the normal subjects, but was not detectable in the senile-cataract patients. The ratio of amino acid concentration in aqueous humor to that in the serum (Ch/Cs) was higher in the cataract patients than in normal subjects for almost all of the compounds we measured.

Amino Acids↗

PubMedDate not supplied

Quantitative analyses of cytomegalovirus genome in aqueous humor of patients with cytomegalovirus retinitis.

PURPOSE: To investigate copy numbers of cytomegalovirus (CMV) in CMV retinitis patients during ganciclovir treatment using real-time polymerase chain reaction (PCR). METHODS: Thirteen aqueous humor samples obtained from 6 patients with clinically diagnosed CMV retinitis were analyzed. As controls, aqueous humor samples were obtained at the time of surgery from patients with senile cataracts. RESULTS: The CMV genome was detected in the range from 10(1) to 10(4) copies/microL of aqueous humor before antiviral treatment. The samples obtained from retinitis patients showing widespread retinal changes contained much higher copy numbers than those from patients with focal lesions. After treatment, the copy number decreased to one hundredth of that observed prior to treatment, but the CMV genome was detectable for 4 to 8 weeks after ganciclovir administration to 4 patients. CONCLUSION: These results revealed the correlation between the copy numbers of the CMV genome and the extent of the area affected by CMV retinitis before antiviral treatment, and the prolonged retention of CMV genome after antiviral treatment. Quantitation of the viral genome after the start of therapy will be of value in determining whether to continue or intensify the dosage of antiviral agents.

Adult↗

PubMed1998

Aqueous humor uric acid and ascorbic acid concentrations and outcome of trabeculectomy.

OBJECTIVE: To determine if there is an association between the surgical outcome of trabeculectomy and uric acid and ascorbic acid concentrations in the aqueous humor at the time of the procedure. PATIENTS, MATERIALS, AND METHODS: Aqueous humor samples were collected from the eyes of 169 of 249 adult patients who underwent trabeculectomy alone for any type of glaucoma between April 1989 and July 1995. Postoperatively, all medical records were reviewed and outcomes were classified as successful, unsuccessful, or indeterminate. The ascorbic acid and uric acid concentrations were determined in masked fashion by high-pressure liquid chromatography. Factors associated with surgical outcome were determined. RESULTS: Uric acid concentration was higher in unsuccessful eyes (mean+/-SD, 0.21+/-0.08 mmol/L, n=26) than in successful eyes (0.15+/-0.09 mmol/L, n=91, 95% confidence interval for difference, 0.02-0.10 mmol/L). Ascorbic acid levels were not significantly different in the eyes with unsuccessful (1129.9+/-601.9 micromol/L) and successful (1334.3+/-511.0 micromol/L) surgery (95% confidence interval for difference, -475.2 to 66.4 micromol/L, P=.13) surgery. Other factors associated with failure were previous surgery and surgery performed at the inferior limbus. A multiple polytomous logistic regression analysis was performed, after excluding the small number of operations performed at the inferior limbus. The odds ratio for failure increased by a factor of 1.68 for every 1-mmol/L increase in uric acid (95% confidence interval, 1.16-2.43, P=.006). CONCLUSIONS: Uric acid levels were higher at the time of surgery in eyes that had unsuccessful outcomes than in those with successful outcomes. No significant difference in ascorbic acid levels was detectable. A higher uric acid level in the aqueous humor is a risk factor for trabeculectomy failure and might be tested as a prognostic indicator [corrected].

Aged↗

PubMed1988

Aqueous humor flow rate and intraocular pressure during and after pregnancy.

Intraocular pressure and aqueous humor formation rate have been determined from the first trimester of pregnancy through term, with further determinations 3 months postpartum, in 7 patients. The intraocular pressure showed a consistent, statistically significant fall during pregnancy, returning to values seen in early pregnancy after delivery. Aqueous humor formation rate showed no change during pregnancy. The data indicate that the sustained elevated hormonal levels during pregnancy, either directly or indirectly, cause an increase in fluid outflow conductance from the eye without altering the rate of fluid entry.

Adult↗

PubMed1993

The penetration of oral ciprofloxacin into the aqueous humor, vitreous, and subretinal fluid of humans.

We examined ciprofloxacin levels in the aqueous humor, vitreous, or subretinal fluid in 40 patients undergoing cataract extraction, vitrectomy, or scleral buckling. Ciprofloxacin, 750 mg, was administered orally an average of 17 1/2 and 5 1/2 hours preoperatively. We obtained mean ciprofloxacin levels of 0.53 microgram/ml in aqueous humor, 0.51 microgram/ml in vitreous, and 0.71 microgram/ml in subretinal fluid. These vitreous levels exceed the minimum inhibitory concentration (MIC)90 of Staphylococcus epidermidis, Propionibacterium species, Pseudomonas aeruginosa, Proteus mirabilis, and Haemophilus influenzae, as well as the MIC70 of S. aureus and Bacillus cereus. Therefore, ciprofloxacin may have a role in the management and prevention of endophthalmitis.

Administration, Oral↗

PubMed1998

Combination of systemic acetazolamide and topical dorzolamide in reducing intraocular pressure and aqueous humor formation.

OBJECTIVE: The study aimed to determine whether topical dorzolamide and systemic acetazolamide have an additive effect on intraocular pressure (IOP) and aqueous humor formation (AHF). DESIGN: This was a prospective, open-label, two-protocol clinical study. PARTICIPANTS: Sixteen patients with ocular hypertension or with primary open-angle glaucoma were studied. INTERVENTION: Baseline AHF was measured by computerized fluorophotometry and IOP by pneumatonometry without antiglaucoma therapy. In the first protocol, dorzolamide was randomized to one eye (N = 10) and IOP and AHF measurements were repeated. One week later, having used dorzolamide in one eye three times daily, patients had measurements performed before and after the single administration of oral acetazolamide 250 mg. In the second protocol, having used acetazolamide 250 mg four times daily for 4 to 7 days (N = 6), patients had measurements performed before and after a single drop of dorzolamide was instilled randomly into one eye. The patient continued acetazolamide and unilateral dorzolamide for 4 to 7 more days and returned for IOP and AHF measurements. MAIN OUTCOME MEASURES: Intraocular pressure and AHF were measured in treated and contralateral control eyes. RESULTS: In the first protocol, IOP (mmHg +/- standard deviation) was significantly (P = 0.02) lower in the dorzolamide (16.3 +/- 2.6) than in the contralateral control (19.9 +/- 2.9) eyes. Aqueous humor formation (microliter/minute +/- standard deviation) also was lower (P = 0.02) in dorzolamide eyes (1.79 +/- 0.4 vs. 2.33 +/- 0.5). After oral acetazolamide 250 mg, IOP was unchanged in dorzolamide eyes (17.6 +/- 2.0 preacetazolamide vs. 17.9 +/- 2.0 postacetazolamide), whereas it was reduced (P = 0.003) in control eyes (20.5 +/- 2.2 preacetazolamide vs. 16.9 +/- 2.3 postacetazolamide). Aqueous humor formation was reduced in control eyes (2.31 +/- 0.8 preacetazolamide vs. 1.73 +/- 0.6 postacetazolamide; P = 0.005) but not in dorzolamide-treated eyes (1.56 +/- 0.45 preacetazolamide vs. 1.77 +/- 0.39 postacetazolamide). In the second protocol, acetazolamide 250 mg four times daily symmetrically reduced IOP and AHF in both eyes. After single-drop dorzolamide in one eye, IOP and AHF did not change significantly. After 4 to 7 days of acetazolamide and unilateral dorzolamide, IOP and AHF remained reduced to a similar level in dorzolamide and control eyes not receiving topical therapy. CONCLUSION: Topical dorzolamide and oral acetazolamide, in the concentrations and doses used in this study, are not additive. Either drug alone results in maximum reduction in IOP and AHF. Concomitant glaucoma therapy of a topical and systemic carbonic anhydrase inhibitor is not warranted.

Acetazolamide↗

PubMed1988

Tissue plasminogen activator in human aqueous humor and its possible therapeutic significance.

By using an enzyme-linked immunosorbent assay, we detected a significant amount of tissue plasminogen activator (0.8 +/- 0.17 ng/ml) in the aqueous humor of ten normal human eyes. It was also identified on Western blot analysis. The ratio of tissue plasminogen activator to total protein in aqueous humor was about 30 times greater than the ratio of tissue plasminogen activator to total protein in plasma. There was evidence that at least some of the tissue plasminogen activator in the aqueous humor was synthesized locally by the structures bordering the anterior chamber of the eye. Tissue plasminogen activator may be a useful therapeutic modality in clinical conditions of delayed dissolution of fibrin in the eye.

Aqueous Humor↗

PubMed2006

Aqueous humor levels of vascular endothelial growth factor and pigment epithelium-derived factor in polypoidal choroidal vasculopathy and choroidal neovascularization.

PURPOSE: To determine the aqueous levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) in patients with active polypoidal choroidal vasculopathy (PCV) and choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD) and pathologic myopia. DESIGN: Prospective, comparative control study. METHODS: Aqueous humors were collected from 32 eyes of 32 patients for either active PCV or CNV. Among them, 11 eyes had active and symptomatic PCV, 12 eyes had active CNV secondary to AMD, and nine eyes had active CNV of pathologic myopia. Levels of VEGF and PEDF were determined by commercially available enzyme-linked immunosorbent assay kits. A group of 10 aqueous samples from 10 patients who underwent cataract surgery without other ocular or systemic diseases comprised the controls. RESULTS: VEGF concentrations in aqueous humor were markedly increased in patients with PCV, CNV of AMD, and CNV of myopia when compared with the controls (analysis of variance [ANOVA], P < .001). VEGF levels in eyes with PCV were, however, significantly lower than those of exudative AMD (P = .045). The PEDF levels were also significantly different among the groups (ANOVA, P = .001), and we observed increased levels in PCV, CNV of AMD, and CNV of myopia. CONCLUSIONS: VEGF and PEDF factors were coexpressed and increased with positive correlation in aqueous humor of eyes with active PCV. The different levels of both factors in eyes of PCV and AMD might suggest distinct clinical entities or different angiogenesis courses between PCV and AMD.

Adult↗

PubMed1992

Detection, quantification, and significance of basic fibroblast growth factor in the aqueous humor of man, cat, dog and pig.

By using a highly specific and sensitive heterologous radioimmunoassay, we determined the content of basic fibroblast growth factor (bFGF) in fresh samples of aqueous humor obtained from human (n = 18), feline (n = 8), canine (n = 12), and porcine (n = 10) eyes by paracentesis. The content of bFGF in human aqueous humor ranged from 0.480 to 1.44 ng ml-1 (mean +/- S.D. = 1.074 +/- 0.297 ng ml-1); in feline samples, from 0.672 to 1.152 ng ml-1 (1.016 +/- 0.158 ng ml-1); in canine samples, from 0.640 to 1.232 ng ml-1 (1.026 +/- 0.171 ng ml-1); and in porcine samples, from 0.627 to 0.957 ng ml-1 (0.728 +/- 0.115 ng ml-1). These values were confirmed by means of a dot/slot-blot technique. For all species, the aqueous samples had normal protein levels that ranged from 5 to 19 mg dl-1. There was no correlation of the content of bFGF with the level of protein or with age of the human subjects. The similarity in the concentrations of bFGF in the aqueous humor as well as the stability of the blood-aqueous barriers of all four species indicate that cats, dogs, and pigs can serve as suitable animal models for the study of the role of bFGF in health and disease. We suggest the possible involvement of bFGF in the pathogenesis of anterior-segment disorders, such as neovascular glaucoma, and in the wound-healing response of limbal tissues after glaucoma filtration surgery.

Aged↗

PubMed2002

Elevated immunoreactive-adrenomedullin levels in the aqueous humor of patients with uveitis and vitreoretinal disorders.

To clarify possible involvement of adrenomedullin in the pathophysiology of inflammation of eyes, we measured immunoreactive-adrenomedullin concentrations in the aqueous humor and plasma obtained from 14 control subjects and 56 patients with uveitis or vitreoretinal disorders. Immunoreactive-adrenomedullin levels in the aqueous humor were significantly elevated in patients with active uveitis, proliferative vitreoretinopathy and proliferative diabetic retinopathy, as compared with control subjects. The plasma immunoreactive-adrenomedullin levels were not significantly correlated with the aqueous humor levels. These findings suggest that adrenomedullin produced locally in the eyes is involved in the pathophysiology of uveitis and some proliferative vitreoretinal disorders.

Adrenomedullin↗