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Molecular Vision Nov 2003In a previous toxicological study, cultured bovine lenses exposed to three topical anesthetics displayed distinct patterns of optical damage and recovery. This work... (Comparative Study)
Comparative Study
PURPOSE
In a previous toxicological study, cultured bovine lenses exposed to three topical anesthetics displayed distinct patterns of optical damage and recovery. This work investigated the epithelial activity of the metabolic enzymes hexokinase (HK) and glucose-6-phosphate dehydrogenase (G6PD) in lenses recovering from anesthetic-induced damage.
METHODS
Cultured bovine lenses were exposed to the anesthetics Alcaine, Fluress and Fluoracaine for 2 h. An automated laser scanner was used to determine the focal length variability (FLV) of the lenses at time-points up to 24 h following their return to fresh culture medium. The epithelial enzyme activities for HK and G6PD were then assayed at the 24 h time-point.
RESULTS
Lenses exposed to Alcaine displayed an abrupt increase in FLV, while Fluoracaine treated lenses exhibited optical damage at a slower rate. The FLV in these two groups recovered to near-control levels after 24 h. Fluress treated lenses did not differ in FLV from controls at any time. The activities of both HK and G6PD were significantly reduced in epithelial samples from each of the three anesthetic treatment groups, relative to controls.
CONCLUSIONS
These results show that lens optical quality can recover despite a severe reduction in epithelial HK and G6PD activity, indicating that the optical function of the lens may not be directly related to epithelial metabolic activity. The ScanTox In Vitro Assay System provides an objective measure of lens optical quality, enabling a direct comparison of optical damage and recovery to lens biochemical changes.
Topics: Anesthetics, Local; Animals; Cattle; Chlorobutanol; Culture Media; Drug Combinations; Edetic Acid; Epithelial Cells; Fluorescein; Fluoresceins; Glucosephosphate Dehydrogenase; Hexokinase; Lens, Crystalline; Organ Culture Techniques; Povidone; Preservatives, Pharmaceutical; Procaine; Propoxycaine
PubMed: 14627957
DOI: No ID Found -
The British Journal of Ophthalmology Nov 1993A novel ophthalmic drug delivery system (NODS) has been developed to give precise and controlled delivery of a drug to the eye. The drug is incorporated into a polyvinyl... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
A comparison of the efficacy and duration of action of topically applied proxymetacaine using a novel ophthalmic delivery system versus eye drops in healthy young volunteers.
A novel ophthalmic drug delivery system (NODS) has been developed to give precise and controlled delivery of a drug to the eye. The drug is incorporated into a polyvinyl alcohol flag attached to a carrier. When applied to the eye the flag detaches and gradually dissolves, releasing the drug. We investigated corneal anaesthesia produced by different concentrations of proxymetacaine NODS, and conventional eye drops. Subjects consisted of 28 normal males (mean age 25.3 (SD 3.9) years). Corneal touch sensitivity was measured with a biomicroscope mounted Cochet-Bonnet aesthesiometer. Each subject attended for two visits separated by 7 days. On each visit each eye randomly received one of four proxymetacaine preparations: 44 micrograms, 74 micrograms, 124 micrograms NODS, or 35 microliters of 0.5% proxymetacaine drops (175 micrograms). Corneal touch sensitivity was measured before, and at 1, 2, 5, 10, 15, 20, 30, 45, and 60 minutes following instillation. Complete anesthesia was achieved in the majority of subjects within 1 minute of instillation. The lowest NODS dose (44 micrograms) produced longer lasting anaesthesia than the 35 microliters drop (175 micrograms) (p < 0.05). Higher NODS doses produced a correspondingly greater increase in the duration of anaesthesia. The greater bioavailability achieved by this vehicle allows much lower drug concentrations to be used, reducing the likelihood of systemic adverse reactions.
Topics: Adult; Anesthetics, Local; Cornea; Dose-Response Relationship, Drug; Humans; Male; Ophthalmic Solutions; Propoxycaine; Time Factors; Touch
PubMed: 8280685
DOI: 10.1136/bjo.77.11.713 -
Zeitschrift Fur Naturforschung. C,... 2002Experimental results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of proparacaine to...
Experimental results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of proparacaine to isolated toad skin, which may reflect an inhibition of the active transport of ions. This finding was explained on the basis of the results obtained from membrane models incubated with proparacaine. These consisted of human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), phospholipid multilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representatives of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively, and in large unilamellar vesicles (LUV) of DMPC X-ray diffraction showed that proparacaine interaction with DMPC and DMPE bilayers perturbed both structures, especially DMPC. This result, confirmed by fluorescence spectroscopy of DMPC LUV at 18 degrees C, demonstrated that the local anesthetic (LA) could interact with the lipid moiety of cell membranes. However, effects observed by scanning electron microscopy (SEM) of human erythrocytes and by fluorescence spectroscopy of IUM might also imply proparacaine-protein interactions. Thus, the LA may alter epitheial sodium channels through interaction with the lipid matrix and with channel protein residues.
Topics: Anesthetics, Local; Animals; Anura; Biological Transport; Cell Membrane; Erythrocyte Membrane; Erythrocytes; Isomerism; Lipid Bilayers; Microscopy, Electron, Scanning; Propoxycaine; Skin; Skin Physiological Phenomena; Sodium
PubMed: 12440736
DOI: 10.1515/znc-2002-9-1029 -
The British Journal of Ophthalmology Feb 2001
Clinical Trial Randomized Controlled Trial
Topics: Adult; Aged; Aged, 80 and over; Anesthetics, Local; Cyclopentolate; Double-Blind Method; Humans; Isomerism; Middle Aged; Mydriatics; Ophthalmic Solutions; Pain; Pain Measurement; Propoxycaine
PubMed: 11225579
DOI: 10.1136/bjo.85.2.238g -
American Journal of Ophthalmology May 1994We compared the potential for bacterial contamination of a proparacaine hydrochloride solution preserved with benzalkonium chloride, which is used with fluorescein paper... (Comparative Study)
Comparative Study
We compared the potential for bacterial contamination of a proparacaine hydrochloride solution preserved with benzalkonium chloride, which is used with fluorescein paper for tonometry, to that of a fluorescein-benoxinate hydrochloride combination solution preserved with chlorobutanol. We contaminated bottles of each solution with Pseudomonas aeruginosa or Staphylococcus aureus (10(7) organisms per milliliter of eyedrop solution). From the fluorescein-benoxinate hydrochloride solution, Staphylococcus organisms were cultured in declining numbers over time, with a half-life of nine seconds, and no Staphylococcus organisms were recovered after five minutes. Pseudomonas organisms disappeared from this solution within 15 seconds. Neither species was viable after 15 seconds in the proparacaine hydrochloride solution. Additionally, we cultured 12 bottles of fluorescein-benoxinate hydrochloride and 15 bottles of proparacaine hydrochloride that had been in use in the clinic for one month. No organisms were recovered from a drop dispensed from any bottle or from the tips, caps, rims, or solution from within any bottle, except that five colonies of Staphylococcus grew from the external rim of one bottle. We conclude that both solutions sterilize themselves rapidly and effectively. Either may be used safely for tonometry.
Topics: Bacteriological Techniques; Colony Count, Microbial; Drug Contamination; Fluorescein; Fluoresceins; Ophthalmic Solutions; Preservatives, Pharmaceutical; Prevalence; Propoxycaine; Pseudomonas aeruginosa; Staphylococcus aureus; Sterilization; Tonometry, Ocular
PubMed: 8172262
DOI: 10.1016/s0002-9394(14)70062-5 -
Indian Journal of Ophthalmology 2011A pilot study was designed to evaluate the safety and efficacy of 23-gauge vitrectomy under topical anesthesia. Five eyes of five patients underwent 23-gauge sutureless...
A pilot study was designed to evaluate the safety and efficacy of 23-gauge vitrectomy under topical anesthesia. Five eyes of five patients underwent 23-gauge sutureless vitrectomy under topical anesthesia with a pledget soaked in 0.5% proparacaine hydrochloride anesthetic, for vitreous hemorrhage (four eyes), epiretinal membrane (one eye). Subjective pain and discomfort were graded using a visual analogue chart from 0 (no pain or discomfort) to 4 (severe pain and discomfort). At the end of surgery no patch was applied and patients were given dark glasses. Patients underwent an immediate postoperative assessment, followed by next day and one week postoperative evaluation. Four patients had Grade 0 pain during the surgery. One patient had Grade 1 pain during the placement and withdrawal of the micro cannulas. The surgical outcomes were favorable. 23-gauge vitrectomy under topical anesthesia is safe and effective in selected cases. Further study is recommended to validate the outcome of this study.
Topics: Adult; Anesthesia, Local; Anesthetics, Local; Catheters; Equipment Design; Follow-Up Studies; Humans; Middle Aged; Pilot Projects; Propoxycaine; Treatment Outcome; Vitrectomy
PubMed: 21350284
DOI: 10.4103/0301-4738.77038 -
The British Journal of Ophthalmology Mar 2005Sub-Tenon's block (STB) or topical anaesthesia alone (TOP) are popular techniques employed during cataract surgery. TOP is often preferred by healthcare providers... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND/AIM
Sub-Tenon's block (STB) or topical anaesthesia alone (TOP) are popular techniques employed during cataract surgery. TOP is often preferred by healthcare providers because of financial or staffing reasons, despite existing evidence that pain during surgery is better controlled with STB. Pain is not the only consideration that determines patient preference for the anaesthesia technique. The authors decided to investigate the issue of patient satisfaction using the recently developed Iowa Satisfaction with Anesthesia Scale (ISAS).
METHOD
In a randomised controlled pilot trial, 28 patients were enrolled to receive either STB with 3 ml of 2% lidocaine and hyaluronidase, or TOP with proxymetacaine 0.5% and amethocaine 1% (Tetracaine) eye drops. Postoperatively patients rated their satisfaction with anaesthesia care by filling in the self administered written questionnaire, the ISAS.
RESULTS
One patient in the TOP group dropped out of the study because of intolerable pain. Analysis of the questionnaire results with a two sample Wilcoxon rank sum test showed a significant difference in patient satisfaction (p<0.0085). The median satisfaction score was higher in the STB group 2.77 (interquartile range IQR 2.45 to 3), than in the TOP group 2.04 (IQR 1.54 to 2.5).
CONCLUSION
In the setting of day case cataract surgery, patients report significantly higher satisfaction scores with STB than with TOP alone.
Topics: Administration, Topical; Aged; Ambulatory Surgical Procedures; Anesthesia, Local; Anesthetics, Local; Cataract Extraction; Eye; Female; Humans; Hyaluronoglucosaminidase; Injections; Lidocaine; Male; Patient Satisfaction; Propoxycaine; Statistics, Nonparametric; Surveys and Questionnaires; Tetracaine
PubMed: 15722306
DOI: 10.1136/bjo.2004.052167 -
CMAJ : Canadian Medical Association... Feb 1987
Topics: Adult; Anesthetics, Local; Female; Humans; Keratitis; Propoxycaine
PubMed: 3815202
DOI: No ID Found -
American Journal of Veterinary Research Oct 2006To determine duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in domestic shorthair (DSH) cats. (Clinical Trial)
Clinical Trial
OBJECTIVE
To determine duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in domestic shorthair (DSH) cats.
ANIMALS
20 clinically normal DSH cats.
PROCEDURES
Baseline corneal touch threshold (CCT) was established by use of a Cochet-Bonnet aesthesiometer. Treatment consisted of a single 50-microL topical application of an ophthalmic preparation of 0.5% proparacaine solution to a randomly selected eye of each cat. The corneal touch threshold was assessed 1 and 5 minutes after application to the cornea and at 5- minute intervals thereafter for 60 minutes.
RESULTS
Corneal sensitivity, as determined by Cochet-Bonnet aesthesiometry, was significantly reduced from baseline for 25 minutes following topical administration of ophthalmic proparacaine. Maximal anesthetic effect lasted 5 minutes.
CONCLUSIONS AND CLINICAL RELEVANCE
As determined by Cochet-Bonnet aesthesiometry, duration of anesthetic effects on the cornea induced by a single topical application of an ophthalmic preparation of 0.5% proparacaine solution in DSH cats is considerably shorter than the reported duration of corneal anesthesia in dogs.
Topics: Administration, Topical; Anesthesia, Local; Anesthetics, Local; Animals; Cats; Cornea; Health; Ophthalmic Solutions; Propoxycaine; Random Allocation
PubMed: 17014333
DOI: 10.2460/ajvr.67.10.1780 -
Anaesthesia Sep 2013
Topics: Anesthetics, Local; Female; Humans; Lidocaine; Male; Ophthalmologic Surgical Procedures; Propoxycaine; Strabismus
PubMed: 24047367
DOI: 10.1111/anae.12403