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Biomedical subjects

M B Abelson

Publications and source records attributed to M B Abelson.

At least 19 recordsLinked to original sources
PubMed1998

Combined analysis of two studies using the conjunctival allergen challenge model to evaluate olopatadine hydrochloride, a new ophthalmic antiallergic agent with dual activity.

PURPOSE: To evaluate the effectiveness and safety of olopatadine hydrochloride and to determine its optimal concentration and the onset and duration of action for treating allergic conjunctivitis. Olopatadine is a new topical ophthalmic antiallergic agent that demonstrates activity as both an antihistamine and a mast cell stabilizer. Two double-masked, randomized, placebo-controlled, contralateral eye comparison studies were conducted using the conjunctival allergen challenge model. METHODS: A total of 169 subjects received 0.05% or 0.1% olopatadine. Study subjects were healthy adult men and women with a history of active allergic conjunctivitis within the previous two seasons but not receiving current treatment. With an allergen dose that produced signs and symptoms of allergic conjunctivitis at visits 1 and 2, the conjunctival allergen challenge was performed 27 minutes after study drug administration at the third visit (onset-of-action challenge) and at 8 hours after study drug administration at the fourth visit (duration-of-action challenge). Olopatadine was administered in one eye and placebo in the opposite eye. Itching and redness were scored for both eyes at 3, 10, and 20 minutes after the conjunctival allergen challenge. RESULTS: Both 0.05% and 0.1% concentrations of olopatadine were significantly (P < .05) more effective than placebo in inhibiting itching and redness at all evaluations when administered 27 minutes or 8 hours before the conjunctival allergen challenge. There were no serious or drug-related ocular or nonocular adverse events in either study. CONCLUSION: These findings demonstrate the rapid and prolonged (at least 8 hours) ocular antiallergic action of olopatadine.

Adolescent↗
PubMed1998

Evaluation of olopatadine, a new ophthalmic antiallergic agent with dual activity, using the conjunctival allergen challenge model.

BACKGROUND: An ophthalmic antiallergic agent with selective H1 antihistaminic and mast cell stabilizing properties has been developed. OBJECTIVES: To evaluate efficacy and safety, determine optimal concentration, and demonstrate onset and duration of action of this new drug, olopatadine. METHODS: This was a placebo-controlled, randomized, double-masked, parallel-group, single-center study with five outpatient visits at least 7 days apart. Ninety-eight healthy, allergy-positive, subjects with a recent history of active allergic conjunctivitis not receiving current treatment participated. Conjunctival allergen challenge (CAC) tests were performed on visits 1 and 2 to identify an allergen and concentration that consistently elicited signs and symptoms of allergic conjunctivitis. On visits 3, 4, and 5, CAC was performed 27 minutes, 8 hours, and 6 hours, respectively, after instillation of one drop of olopatadine (0.01%, 0.05%, 0.1%, or 0.15%) in one eye and placebo in the other. Both eyes were scored for the intensity of itching and redness at 3, 10, and 20 minutes after the CAC. RESULTS: All four concentrations of olopatadine were clinically and statistically superior to placebo in preventing ocular itching at all evaluations and preventing redness at most evaluations from immediately and 8 hours after drug administration. No drug-related adverse events were reported. The 0.1% concentration was found to be most effective. CONCLUSIONS: The results indicate that olopatadine ophthalmic solution is safe and effective in the treatment of allergic conjunctivitis, with the 0.1% concentration of olopatadine being optimal. The rapid onset and at least 8 hour duration of action of olopatadine indicates that the drug can be used twice daily.

Adult↗
PubMed1998

A multicenter comparison of the ocular efficacy and safety of diclofenac 0.1% solution with that of ketorolac 0.5% solution in patients with acute seasonal allergic conjunctivitis.

Only one of several available ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) is currently FDA approved for use in acute seasonal allergic conjunctivitis (SAC). Sixty patients with SAC and moderate itching and bulbar conjunctival injection were enrolled in a multicenter, randomized, double-masked, parallel-group trial comparing diclofenac sodium (DS) with ketorolac tromethamine (KT). Patients instilled 1 drop four times daily while awake for 14 days. Ocular signs and symptoms were evaluated at one and two weeks. The primary efficacy variables were itching and bulbar conjunctival injection. For both treatments, the ocular allergy sign and symptom scores were comparable at baseline. Both treatments evaluated in this study were well tolerated. Significant clinical and statistical reductions from baseline were observed in the primary efficacy variables. Treatment group differences were observed for the pain/soreness score with an advantage observed for the DS group at 30 minutes and at day 7. Our conclusion is that diclofenac sodium and ketorolac tromethamine acted similarly to reduce the ocular signs and symptoms associated with acute seasonal allergic conjunctivitis. There was a statistically significant advantage for the DS group to be free of symptoms at the day 7 visit as compared to the KT group (20.7% vs. 3.2%).

Acute Disease↗
PubMed1998

Alteration of mucin in human conjunctival epithelia in dry eye.

PURPOSE: The objective of this study was to determine whether alteration in mucins could be detected in patients with dry eye symptoms by using the monoclonal antibody H185, which recognizes carbohydrate epitopes on mucin molecules. METHODS: Immunohistochemistry and immunoelectron microscopy was used to examine binding of H185 antibody to conjunctival cells obtained by nitrocellulose filter paper stripping (impression cytology). Two study populations were examined. Study I included 22 patients with dry eye symptoms and 13 normal volunteers. Study II included 16 aqueous-deficient dry eye patients and 14 age-matched control subjects. RESULTS: Results of the studies demonstrated significant differences in binding patterns of H185 to conjunctival cells in normal eyes compared with those of patients with dry eye symptoms. In normal eyes, the antibody bound to apical cells in a mosaic pattern, with cells exhibiting either light, medium, or intense binding. A predominant pattern in patients with dry eye symptoms was loss of the mosaic pattern with replacement by a "starry sky" pattern in which there was a lack of apical cell binding (hence, dark sky) but increased binding to goblet cells (hence, stars in the sky). The starry sky pattern correlated with rose bengal staining. CONCLUSIONS: From these studies it is concluded that there is an alteration either in mucin distribution or mucin glycosylation on the surfaces of apical conjunctival cells in dry eye and that glycosylation of goblet cell mucins changes with the disease.

Adult↗
PubMed1995

Histaminase activity in patients with vernal keratoconjunctivitis.

PURPOSE: To investigate the activity of histamine-degradating enzymes in tears and plasma of patients with vernal keratoconjunctivitis (VKC). METHOD: Tear and plasma samples were collected from patients with VKC and from age-matched control subjects. Histamine was measured by enzyme-linked immunosorbent assay in acid samples treated with perchloric to deactivate histaminase and in untreated samples. Tear cytology, skin test reactivity to histamine, and the sum clinical score of allergic signs and symptoms in patients with VKC also were evaluated. Nineteen patients with active VKC and six age-matched control subjects participated in this study. RESULTS: In untreated samples, tear histamine (mean +/- standard error of the mean) was 11.15 +/- 2.16 ng/ml in patients with VKC and 0.855 +/- 0.225 ng/ml in control tears (P < 0.001). In treated samples, mean tear histamine was 22.25 +/- 4.17 ng/ml in patients with VKC versus 10.64 +/- 2.85 ng/ml in control subjects (not statistically different). The ratio of histamine in treated to untreated samples (indicating histaminase activity) was significantly lower in patients with VKC (2.30 +/- 0.263) than in control subjects (17.57 +/- 5.97; P = 0.0001). Plasma histamine levels in untreated and treated samples were significantly higher in patients with VKC (untreated, 2.23 +/- 0.334 ng/ml; treated, 4.37 +/- 0.357 ng/ml) than in control subjects (untreated, 0.254 +/- 0.068, P = 0.0002; treated, 2.96 +/- 0.171 ng/ml, P = 0.0082). The enzymatic breakdown of histamine (treated/ untreated) in plasma was significantly decreased in patients with VKC (2.54 +/- 0.447) compared with control subjects (14.78 +/- 4.86; P = 0.0012). Skin reactivity to histamine was not increased in VKC. Tear histamine levels were significantly correlated to tear lymphocyte content in the general population and to tear basophils in the patients with tarsal-vernal VKC only. An increased number of tear eosinophils were correlated with elevated enzyme activity only in patients with tarsal-vernal VKC and to the clinical score only in limbal-vernal patients. CONCLUSION: The enzymatic degradation of histamine was significantly decreased in patients with VKC compared with control subjects in both tears and plasma, suggesting that this dysfunction may be a primary factor in the pathophysiology of VKC.

Adolescent↗
PubMed1995

Evaluation of 0.05% levocabastine versus 4% sodium cromolyn in the allergen challenge model.

PURPOSE: This study was conducted to evaluate the efficacy of 0.05% levocabastine compared with 4% cromolyn for treating allergic conjunctivitis induced by ocular allergen challenge. METHODS: Subjects who met all entry criteria and reacted positively to ocular allergen challenge at two previous visits (n = 50) received placebo in one eye and cromolyn in the fellow eye, four times daily for 2 weeks. On day 18, subjects received the final dose of cromolyn in the pretreated eye and one drop of levocabastine in the fellow eye. Subjects were challenged and evaluated after 3, 5, and 10 minutes. Four hours after drug administration, subjects were rechallenged and evaluated after 3, 5, and 10 minutes. RESULTS: Levocabastine was significantly more effective than cromolyn in inhibiting itching, hyperemia, eyelid swelling, chemosis, and tearing after the initial challenge and 4-hour rechallenge (P < 0.05). CONCLUSION: These results suggest that levocabastine is superior to cromolyn for treating allergen-induced conjunctivitis and has a duration of action of at least 4 hours.

Allergens↗
PubMed1994

Efficacy of lodoxamide 0.1% ophthalmic solution in resolving corneal epitheliopathy associated with vernal keratoconjunctivitis.

A multicenter, randomized, double-masked, parallel-group study compared the long-term efficacy and safety of lodoxamide 0.1% ophthalmic solution and placebo in 118 patients with vernal keratoconjunctivitis. The test drugs were instilled four times daily for 90 days. Lodoxamide 0.1% ophthalmic solution was significantly (P < .05) more effective than placebo in lowering severity scores for epithelial disease and corneal staining, evidence of the superior efficacy of lodoxamide 0.1% ophthalmic solution in reversing the corneal complications commonly associated with moderate to severe vernal keratoconjunctivitis. Additionally, lodoxamide 0.1% ophthalmic solution ameliorated the other key signs of vernal keratoconjunctivitis, including upper tarsal papillae, limbal signs (papillae, hyperemia, and Trantas' dots), and conjunctival discharge. The between-group differences in the relief of symptoms (itching, tearing, and photophobia) were clinically significant but not always statistically significant. Treatment-related adverse events were reported with similar frequency in both treatment groups, and none were serious.

Adolescent↗
PubMed1994

Evaluation of the new ophthalmic antihistamine, 0.05% levocabastine, in the clinical allergen challenge model of allergic conjunctivitis.

The objective of this study was to evaluate the efficacy of 0.05% levocabastine, a new antihistamine formulated for ophthalmic use, compared with the placebo vehicle for the treatment of allergic conjunctivitis induced by ocular allergen challenge. Subjects who reacted. positively in both eyes on two separate occasions to ocular allergen challenge with grass, ragweed, or cat dander (N = 47) received one dose of 1 to 2 drops of 0.05% levocabastine in one eye and its vehicle in the other eye. After 10 minutes, the predetermined dose of allergen was instilled in both eyes. Signs and symptoms of allergic conjunctivitis were evaluated with biomicroscopy and subjective evaluation of itching after 3, 5, and 10 minutes. Four hours after drug administration, subjects were rechallenged and reevaluated to determine levocabastine's duration of action. Results showed that levocabastine was significantly more effective than placebo in inhibiting itching, hyperemia, eyelid swelling, chemosis, and tearing after the initial challenge and in inhibiting all parameters except eyelid swelling after the rechallenge 4 hours later (p < 0.05). These results demonstrate that levocabastine, currently the only ophthalmic antihistamine available that is not combined with a vasoconstrictor, is efficacious in the inhibition of itching, as well as all of the allergic signs of a vascular origin, with a duration of action of at least 4 hours. Because of its strong effects on itching and hyperemia, chemosis, lid swelling, and tearing, levocabastine would be a valuable therapeutic agent to add to the heterogeneous family of antiallergic compounds presently available for the treatment of seasonal allergic conjunctivitis.

Adolescent↗
PubMed1994

Nonsteroidal anti-inflammatory drugs. Current ophthalmic therapy.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in the treatment of ophthalmic inflammatory disease. Currently four topical preparations are available: flurbiprofen and suprofen for the prevention of miosis during surgery; diclofenac for postoperative inflammation following cataract extraction, and ketorolac for the treatment of itching associated with seasonal allergic conjunctivitis. Caution should be exercised, however, as topical and systemic adverse effects may occur including stinging, photophobia, gastric sensitivity, and increased bleeding time. The mechanism of action of NSAIDs is discussed, complications associated with use, and the current and future roles of therapy.

Administration, Oral↗
PubMed1993

Complications and symptoms with disposable daily wear contact lenses and conventional soft daily wear contact lenses.

We conducted a historical cohort study of 1,954 myopic cosmetic contact lens wearers (1,258 disposable soft daily wear lens users and 696 conventional [nondisposable] soft daily wear lens users). Our aim was to estimate the rates of complications and symptoms among patients using daily wear disposable contact lenses on a regular disposal regimen and to compare these with rates for conventional soft daily wear users. Patients were selected from five contact lens practices in Denmark. Data were abstracted from the eye care practitioners' office records for the period October 1987 through December 1989. Virtually all of the disposable lens users were on a two-week disposal regimen. Overall, the prevalence of complications was significantly lower among the daily wear disposable lens users than among the conventional soft daily wear lens users. The incidence of corneal ulcers did not differ significantly between the two study groups. As compared to conventional soft daily wear lens users, disposable daily wear lens users reported symptoms less frequently at routine scheduled visits and had a lower rate of unscheduled visits for complications and symptoms.

Adult↗
PubMed1992

Preservative-free artificial tear preparations. Assessment of corneal epithelial toxic effects.

Scanning electron microscopy was used to evaluate the corneal epithelium of rabbit eyes after administration of two preservative-free ocular lubricants, preservative-free artificial tear-1 (Hypotears PF) and preservative-free artificial tear-2 (Refresh), and 0.02% benzalkonium chloride. Animals were randomly assigned to either mild or exaggerated use regimens. A quantitative rating system was used to assess epithelial damage. With mild use, scanning electron microscopy revealed normal epithelial morphologic characteristics for both preservative-free artificial tear solutions (mean relative damage score, solution 1, 0.75 +/- 0.16; solution 2, 1.02 +/- 0.23), which were not significantly different from eyes treated with phosphate-buffered saline (1.38 +/- 0.38) or a mild dosage regimen of 0.02% benzalkonium chloride (1.20 +/- 0.12). Exaggerated use with preservative-free artificial tear solutions (solution 1, 1.31 +/- 0.21; solution 2, 1.35 +/- 0.08) induced minimal damage that was not different from control eyes treated with phosphate-buffered saline (1.26 +/- 0.13). Compared with an exaggerated use of 0.02% benzalkonium chloride (4.0 +/- 0.16), both preservative-free artificial tear solutions induced significantly less epithelial damage (P = .0001). These results suggest that with frequent-dosage regimens, preservation-free artificial tear solutions-1 and -2 are free of the toxic effects associated with preserved solutions.

Animals↗
PubMed1992

Eicosanoid modulation and epithelial wound healing kinetics of the alkali-burned cornea.

The cyclooxygenase and lipoxygenase enzyme systems can metabolize a number of C20 polyunsaturated fatty acids. Although arachidonic acid is the usual substrate for these pathways, the eicosanoid precursor pool can be nutritionally manipulated by supplementation with alternative precursors, often generating less active or down-regulatory metabolic products. Prefeeding with gamma-linolenic acid, eicosapentaenoic acid, or a combination of both failed to influence the lagphase, epithelial migration rate, or epithelial wound healing kinetics after either 1N or 4N NaOH alkali burning of the rabbit cornea. Initial epithelial wound healing probably does not involve eicosanoid-mediated processes. Essentially linear epithelial healing kinetics continued to closure without a late decrease in wound edge velocity.

Alkalies↗
PubMed1991

Allergic conjunctivitis: a survey of new antihistamines.

The objective of this study was to determine the therapeutic value of a wide variety of H1 antihistamines for potential ophthalmic use by performing ocular toxicity and efficacy tests in rabbits and humans. Fourteen antihistamines were formulated into ophthalmic preparations and were screened in the rabbit model; of these, thirteen were preliminary evaluated for toxicity and efficacy in humans. Based on comfort and efficacy, four (pheniramine, chlorpheniramine, dexbrompheniramine and pyrilamine) were selected for more extensive dose response and efficacy testing. 0.3% chlorpheniramine, dexbrompheniramine, pyrilamine and pheniramine significantly reduced histamine-induced itching (p less than or equal to 0.01 for each drug) and conjunctival injection (p less than or equal to 0.02 for each drug), when compared to contralateral eyes receiving PBS. When compared to 0.3% pheniramine in the fellow eye (mean difference score = 0.79 +/- 0.21), 0.3% chlorpheniramine (1.5 +/- 0.22; p = 0.04) and 0.3% dexbrompheniramine (1.71 +/- 0.18; p = 0.01) were superior in decreasing histamine-induced itching. Dose-response curves demonstrated that 0.4% and 0.5% pheniramine were statistically superior to 0.3% in relieving itching and redness. Compared to 0.3% pheniramine, 0.1% and 0.2% chlorpheniramine and 0.2% pyrilamine were statistically superior in inhibiting redness and itching. The results of this study suggest that 0.1%, 0.2% and 0.3% chlorpheniramine, 0.3% dexbrompheniramine, 0.2% pyrilamine, and 0.4% and 0.5% pheniramine were effective in relieving the itching and conjunctival injection associated with topically applied histamine. These seven formulations should be considered as possible new preparations for use as ophthalmic antihistamines and may warrant further evaluation.

Animals↗