The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Sung Chul Park - One of the best experts on this subject based on the ideXlab platform.
-
effect of Cyclopentolate on in vivo schlemm canal microarchitecture in healthy subjects
Journal of Glaucoma, 2016Co-Authors: Michael S Rosman, Alon Skaat, Jason L Chien, Mark P Ghassibi, Tarela F Sarimiye, Robert Ritch, Jeffrey M Liebmann, Sung Chul ParkAbstract:PURPOSE: To characterize the in vivo effect of Cyclopentolate on the microstructure of Schlemm canal (SC) in healthy eyes. METHODS: For healthy subjects, 81 serial horizontal enhanced depth imaging optical coherence tomography B-scans (interval between scans, ∼35 μm) of the nasal corneoscleral limbal area were obtained before and 1 hour after Cyclopentolate 1% administration in 1 eye. The structures of aqueous and blood vessels in each scan were used as landmarks to select 50 overlapping scans between the 2 sets of 81 serial scans (before and after Cyclopentolate administration). The SC cross-sectional area was measured in each of the 50 selected scans. After 3-dimensional reconstruction, SC volume was determined. RESULTS: Twelve eyes (12 healthy subjects) were imaged successfully before and after Cyclopentolate administration. Mean age was 27.8±4.9 years (range, 25 to 38 y). Following Cyclopentolate administration, mean intraocular pressure did not change significantly (13.9±1.5 to 14.2±1.5 mm Hg; P=0.19). Mean SC cross-sectional area decreased by 17%, from 3563±706 to 2959±460 μm (P<0.001). Mean SC volume in the overlapping area (approximately 1.7 mm of circumferential length of SC) decreased from 6,164,061±1,220,787 to 5,119,462±794,763 μm (P<0.001). The decrease in the mean SC cross-sectional area after Cyclopentolate administration was greater in eyes with larger baseline SC cross-sectional area (P<0.001, R=0.873). CONCLUSIONS: Cyclopentolate causes a reduction in SC dimensions in healthy eyes. Future studies are warranted to determine the exact mechanism(s) of this change.
-
Effect of Cyclopentolate on In Vivo Schlemm Canal Microarchitecture in Healthy Subjects.
Journal of Glaucoma, 2016Co-Authors: Michael S Rosman, Alon Skaat, Jason L Chien, Mark P Ghassibi, Tarela F Sarimiye, Robert Ritch, Jeffrey M Liebmann, Sung Chul ParkAbstract:PURPOSE: To characterize the in vivo effect of Cyclopentolate on the microstructure of Schlemm canal (SC) in healthy eyes. METHODS: For healthy subjects, 81 serial horizontal enhanced depth imaging optical coherence tomography B-scans (interval between scans, ∼35 μm) of the nasal corneoscleral limbal area were obtained before and 1 hour after Cyclopentolate 1% administration in 1 eye. The structures of aqueous and blood vessels in each scan were used as landmarks to select 50 overlapping scans between the 2 sets of 81 serial scans (before and after Cyclopentolate administration). The SC cross-sectional area was measured in each of the 50 selected scans. After 3-dimensional reconstruction, SC volume was determined. RESULTS: Twelve eyes (12 healthy subjects) were imaged successfully before and after Cyclopentolate administration. Mean age was 27.8±4.9 years (range, 25 to 38 y). Following Cyclopentolate administration, mean intraocular pressure did not change significantly (13.9±1.5 to 14.2±1.5 mm Hg; P=0.19). Mean SC cross-sectional area decreased by 17%, from 3563±706 to 2959±460 μm (P
Timo Kaila - One of the best experts on this subject based on the ideXlab platform.
-
ocular effects and systemic absorption of Cyclopentolate eyedrops after canthal and conventional application
Acta Ophthalmologica, 2009Co-Authors: K Lahdes, Risto Huupponen, Timo KailaAbstract:: Ocular effects and plasma concentrations of Cyclopentolate were studied in 8 volunteers after eyedrop application with two methods. While recumbent two 30 microliters drops of 1% Cyclopentolate hydrochloride were instilled in randomized order either conventionally to the lower conjunctival cul-de-sac or on the inner canthus with eyes closed, followed by immediate opening of the eyes. The cycloplegic responses as well as the extent and time of maximal mydriasis did not differ significantly between the two methods. None of the parameters describing the systemic absorption of the drug differed between the treatment groups. Conventionally applied drops caused slightly longer subjective discomfort. Instilling eyedrops on the inner canthus with eyes closed is an alternative method to deliver ocular Cyclopentolate with similar efficacy and safety as the conventional technique. This method could be useful especially when treating non-cooperative children.
-
systemic and ocular absorption and antagonist activity of topically applied Cyclopentolate in man
Pharmacology & Toxicology, 1998Co-Authors: Marko Haaga, Timo Kaila, Lotta Salminen, Pauli YlitaloAbstract:: Ocular and systemic absorption and antagonist activity of topical 1% Cyclopentolate were studied in 11 elderly patients undergoing extracapsular cataract extraction, and in 8 healthy female volunteers. The patients received two 35 microl drops of Cyclopentolate unilaterally and the healthy volunteers one 30 microl drop bilaterally to the lower conjunctival cul-de-sac of the eye. The drug concentrations were measured with radioreceptor assay and receptor occupancies with radiooccupancy assay using isolated rat brain muscarinic cholinoceptors. In the patient group, Cyclopentolate concentrations in aqueous humour were approximately 3000 times higher than those in plasma. Muscarinic cholinoceptors were occupied totally (more than 99.9%) by aqueous humour and 3-18% by plasma taken at 55-125 min. after the drug application. In healthy volunteers peak plasma concentration of Cyclopentolate, 2.06+/-0.86 (mean+/-S.D.) nM, occurred at 53 min., maximum receptor occupancy being 5.9+/-2.1%. The maximum pupillary dilatation occured at 30 min. after the drug application. At the same time the near point of vision was extended to more than 50 cm in all subjects. After topical application plasma receptor occupancy was not high enough to cause any significant changes in heart rate and in PQ time. None of the subjects experienced subjectively or objectively adverse effects to be attributed to Cyclopentolate.
-
plasma concentrations and ocular effects of Cyclopentolate after ocular application of three formulations
British Journal of Clinical Pharmacology, 1993Co-Authors: K Lahdes, Risto Huupponen, Timo Kaila, Mf Saettone, Daniela Monti, Lotta SalminenAbstract:1. Eight volunteers received in randomized order two 30 microliters drops of either 1% w/v Cyclopentolate hydrochloride or a corresponding amount of Cyclopentolate polygalacturonate in saline or in acetate buffer in one eye. Cyclopentolate concentrations in plasma were measured by a radioreceptor assay. 2. Peak plasma drug concentrations of about 3 ng ml-1 occurred within 30 min after all formulations. Occasionally, a second concentration peak in plasma, probably reflecting drug absorption from the gastrointestinal tract, was seen after 2 h. The mean elimination half-life of Cyclopentolate was 111 min when all subjects and formulations were considered together. There were no statistically significant differences between the formulations with respect to the time-course of plasma drug concentration. 3. The maximal mydriatic effect was reached within about 15 min and was maintained for several hours, often being 1/3 of its peak value after 30 h. Similarly, an intense cycloplegic response was achieved within a few minutes, the peak changes in the near-point of vision being 9 to 10 dioptres. The cycloplegic response was more intense after one of the polygalacturonate complexes, especially at later time points.
-
The effect of some macromolecular ionic complexes on the pharmacokinetics and -dynamics of ocular Cyclopentolate in rabbits.
Journal of Ocular Pharmacology and Therapeutics, 1992Co-Authors: Risto Huupponen, Timo Kaila, Mf Saettone, Daniela Monti, Esko Iisalo, Lotta Salminen, O. OksalaAbstract:ABSTRACT The effect of mucoadhesive polymeric vehicles on the mydriatic efficacy, and on the systemic and ocular absorption of Cyclopentolate from eyedrops was studied in albino rabbits. Combining Cyclopentolate base to polygalacturonic (CY-PGA) or hyaluronic (CY-HA) acid resulted in an increased mydriatic effect when compared with Cyclopentolate hydrochloride (CY-HCl). During the first half an hour, the systemic absorption of Cyclopentolate was lower after CY-PGA than after CY-HCl. The ocular penetration of Cyclopentolate, based on drug concentrations in aqueous humor 30 minutes after the eyedrop instillation, was increased 3fold when the polygalacturonate complex was used. CY-PGA, as well as other polymeric salts, might offer a possibility to increase the therapeutic index of Cyclopentolate.
-
systemic absorption of ocular Cyclopentolate in children
German journal of ophthalmology, 1992Co-Authors: K Lahdes, Risto Huupponen, Timo Kaila, T Alimelkkila, L Salminen, M SaariAbstract:: Cyclopentolate plasma levels were quantitated and heart rate and pupil size were monitored after ocular application of the drug to juveniles. In all, 12 children were given one 35-microliters eyedrop of either 1% Cyclopentolate (n = 6) or placebo (n = 6) in randomized order in the lower cul-de-sac of one eye. A sensitive radioreceptor assay was used to determine the systemic drug absorption. With the exception of one child, detectable Cyclopentolate concentrations were seen in plasma at as early as 3 min after the ocular drug application. There was a marked interindividual variation in peak plasma Cyclopentolate concentrations ranging from undetectably low to 5.8 ng/ml (median, 2.9 ng/ml). In some children a second drug concentration peak was detected. Cyclopentolate increased the pupillary diameter from 4.8 +/- 1 mm before drug application to 8 +/- 0.9 mm at 30 min after administration, but the children's heart rate did not alter.
Asieh Ehsaei - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Cyclopentolate versus tropicamide on anterior segment angle parameters in three refractive groups.
Clinical & experimental optometry, 2020Co-Authors: Nasrin Moghadas Sharif, Nasser Shoeibi, Maryam Heydari, Negareh Yazdani, Somayeh Ghasemi-moghaddam, Asieh EhsaeiAbstract:Frequent clinical application of cycloplegia in clinical practice makes it essential to assess how this condition influences anterior segment angle parameters. This study aims to compare the effects of Cyclopentolate and tropicamide on anterior segment angle parameters in three adult refractive groups. Sixty healthy individuals were recruited and assigned into three refractive groups according to inclusion criteria. At baseline visit, anterior segment angle parameters were measured using anterior segment optical coherence tomography in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and Cyclopentolate 1% at similar conditions. Main outcome measures were angle-opening distance, trabecular iris angle, trabecular iris space area and anterior chamber depth. Anterior segment angle parameters were recorded at temporal areas (180 degrees). Sixty participants (29 men and 31 women, age: 27.82 ± 4.71 years) completed the experiment. Baseline mean spherical equivalents were +1.52 ± 1.20 D, -0.04 ± 0.33 D and -1.91 ± 0.91 D in hyperopic, emmetropic and myopic groups, respectively. No statistically significant differences were found between tropicamide and Cyclopentolate for all angle parameters in three refractive groups. Both drops induced an increase in all parameters in three refractive groups. Analysis between refractive groups revealed that a more hyperopic refraction was associated with less trabecular iris angle, angle-opening distance and anterior chamber depth parameters in baseline, after tropicamide and Cyclopentolate instillations. Topical application of cycloplegic eye drops in healthy individuals leads to small but significant changes in anterior chamber depth and anterior segment angle parameters, regardless of refractive status. Moreover, lower values of anterior chamber depth and anterior segment angle parameters in hyperopic individuals after administration of cycloplegic drops should be taken into account during biometric measurement and phakic intraocular lens implantation. Due to shorter effect and recovery time and less ocular/systemic reaction of tropicamide versus Cyclopentolate, tropicamide could be a recommended cycloplegic agent for diagnostic and therapeutic procedures. © 2020 Optometry Australia.
-
effect of Cyclopentolate versus tropicamide on anterior segment angle parameters in three refractive groups
Clinical and Experimental Optometry, 2020Co-Authors: Nasrin Moghadas Sharif, Nasser Shoeibi, Maryam Heydari, Negareh Yazdani, Somayeh Ghasemimoghaddam, Asieh EhsaeiAbstract:CLINICAL RELEVANCE Frequent clinical application of cycloplegia in clinical practice makes it essential to assess how this condition influences anterior segment angle parameters. BACKGROUND This study aims to compare the effects of Cyclopentolate and tropicamide on anterior segment angle parameters in three adult refractive groups. METHODS Sixty healthy individuals were recruited and assigned into three refractive groups according to inclusion criteria. At baseline visit, anterior segment angle parameters were measured using anterior segment optical coherence tomography in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and Cyclopentolate 1% at similar conditions. Main outcome measures were angle-opening distance, trabecular iris angle, trabecular iris space area and anterior chamber depth. Anterior segment angle parameters were recorded at temporal areas (180 degrees). RESULTS Sixty participants (29 men and 31 women, age: 27.82 ± 4.71 years) completed the experiment. Baseline mean spherical equivalents were +1.52 ± 1.20 D, -0.04 ± 0.33 D and -1.91 ± 0.91 D in hyperopic, emmetropic and myopic groups, respectively. No statistically significant differences were found between tropicamide and Cyclopentolate for all angle parameters in three refractive groups. Both drops induced an increase in all parameters in three refractive groups. Analysis between refractive groups revealed that a more hyperopic refraction was associated with less trabecular iris angle, angle-opening distance and anterior chamber depth parameters in baseline, after tropicamide and Cyclopentolate instillations. CONCLUSIONS Topical application of cycloplegic eye drops in healthy individuals leads to small but significant changes in anterior chamber depth and anterior segment angle parameters, regardless of refractive status. Moreover, lower values of anterior chamber depth and anterior segment angle parameters in hyperopic individuals after administration of cycloplegic drops should be taken into account during biometric measurement and phakic intraocular lens implantation. Due to shorter effect and recovery time and less ocular/systemic reaction of tropicamide versus Cyclopentolate, tropicamide could be a recommended cycloplegic agent for diagnostic and therapeutic procedures.
-
Comparison of Cyclopentolate versus tropicamide on corneal topography in emmetropic and myopic eyes
2020Co-Authors: Nasrin Moghadas Sharif, Hadi Ostadi Moghadam, Elham Azizi, Elahe Ghoochani, Asieh EhsaeiAbstract:Abstract Background: To compare the effect of Cyclopentolate versus tropicamide eye drops on anterior surface corneal parameters using Keratograph 4 in myopic and emmetropic individuals.Methods: Fifty-eight participants included 29 emmetropic and 29 myopic individuals, were recruited, according to inclusion and exclusion criteria. At baseline visit, anterior surface corneal parameters were measured using Keratograph 4 Keratograph 4in the right eye. All measurements were repeated at two separate visits, one week apart, after administration of tropicamide 1% and Cyclopentolate 1% at similar conditions.Results: Of 58 participants who completed the study, 29 (24 women, 5 men, age: 23.82± 2.78 years) were emmetropic and 29 (21women, 8 men, age: 23.66± 2.76 years) were myopic. Baseline mean spherical equivalents were -0.23±0.23 D and -2.45±1.03 D in emmetropic and myopic groups, respectively. The analysis of the data showed a significant hyperopic shift following instillation of both cycloplegic eye drops in both refractive groups. However, tropicamide results was statistically insignificant in comparison with Cyclopentolate (p=0.49). The assessment of data revealed no statistically significant differences in anterior surface corneal parameters in baseline, tropicamide and Cyclopentolate instillation in each refractive group, except IHD value with tropicamide in myopic group (p=0.02). The further analysis between refractive groups also showed no significant differences in anterior surface corneal parameters in each session.Conclusions: Present study indicates that Cyclopentolate and tropicamide do not appear to affect corneal topographic parameters and hence can be trusted to capture topography data.
-
Comparison of Cyclopentolate versus tropicamide cycloplegia: A systematic review and meta-analysis.
Journal of Optometry, 2017Co-Authors: Negareh Yazdani, Ramin Sadeghi, Hamed Momeni-moghaddam, Leili Zarifmahmoudi, Asieh EhsaeiAbstract:The aim of the present meta-analysis is to compare the efficacy of Cyclopentolate and tropicamide in controlling accommodation during refraction.
Michael S Rosman - One of the best experts on this subject based on the ideXlab platform.
-
effect of Cyclopentolate on in vivo schlemm canal microarchitecture in healthy subjects
Journal of Glaucoma, 2016Co-Authors: Michael S Rosman, Alon Skaat, Jason L Chien, Mark P Ghassibi, Tarela F Sarimiye, Robert Ritch, Jeffrey M Liebmann, Sung Chul ParkAbstract:PURPOSE: To characterize the in vivo effect of Cyclopentolate on the microstructure of Schlemm canal (SC) in healthy eyes. METHODS: For healthy subjects, 81 serial horizontal enhanced depth imaging optical coherence tomography B-scans (interval between scans, ∼35 μm) of the nasal corneoscleral limbal area were obtained before and 1 hour after Cyclopentolate 1% administration in 1 eye. The structures of aqueous and blood vessels in each scan were used as landmarks to select 50 overlapping scans between the 2 sets of 81 serial scans (before and after Cyclopentolate administration). The SC cross-sectional area was measured in each of the 50 selected scans. After 3-dimensional reconstruction, SC volume was determined. RESULTS: Twelve eyes (12 healthy subjects) were imaged successfully before and after Cyclopentolate administration. Mean age was 27.8±4.9 years (range, 25 to 38 y). Following Cyclopentolate administration, mean intraocular pressure did not change significantly (13.9±1.5 to 14.2±1.5 mm Hg; P=0.19). Mean SC cross-sectional area decreased by 17%, from 3563±706 to 2959±460 μm (P<0.001). Mean SC volume in the overlapping area (approximately 1.7 mm of circumferential length of SC) decreased from 6,164,061±1,220,787 to 5,119,462±794,763 μm (P<0.001). The decrease in the mean SC cross-sectional area after Cyclopentolate administration was greater in eyes with larger baseline SC cross-sectional area (P<0.001, R=0.873). CONCLUSIONS: Cyclopentolate causes a reduction in SC dimensions in healthy eyes. Future studies are warranted to determine the exact mechanism(s) of this change.
-
Effect of Cyclopentolate on In Vivo Schlemm Canal Microarchitecture in Healthy Subjects.
Journal of Glaucoma, 2016Co-Authors: Michael S Rosman, Alon Skaat, Jason L Chien, Mark P Ghassibi, Tarela F Sarimiye, Robert Ritch, Jeffrey M Liebmann, Sung Chul ParkAbstract:PURPOSE: To characterize the in vivo effect of Cyclopentolate on the microstructure of Schlemm canal (SC) in healthy eyes. METHODS: For healthy subjects, 81 serial horizontal enhanced depth imaging optical coherence tomography B-scans (interval between scans, ∼35 μm) of the nasal corneoscleral limbal area were obtained before and 1 hour after Cyclopentolate 1% administration in 1 eye. The structures of aqueous and blood vessels in each scan were used as landmarks to select 50 overlapping scans between the 2 sets of 81 serial scans (before and after Cyclopentolate administration). The SC cross-sectional area was measured in each of the 50 selected scans. After 3-dimensional reconstruction, SC volume was determined. RESULTS: Twelve eyes (12 healthy subjects) were imaged successfully before and after Cyclopentolate administration. Mean age was 27.8±4.9 years (range, 25 to 38 y). Following Cyclopentolate administration, mean intraocular pressure did not change significantly (13.9±1.5 to 14.2±1.5 mm Hg; P=0.19). Mean SC cross-sectional area decreased by 17%, from 3563±706 to 2959±460 μm (P
K Lahdes - One of the best experts on this subject based on the ideXlab platform.
-
ocular effects and systemic absorption of Cyclopentolate eyedrops after canthal and conventional application
Acta Ophthalmologica, 2009Co-Authors: K Lahdes, Risto Huupponen, Timo KailaAbstract:: Ocular effects and plasma concentrations of Cyclopentolate were studied in 8 volunteers after eyedrop application with two methods. While recumbent two 30 microliters drops of 1% Cyclopentolate hydrochloride were instilled in randomized order either conventionally to the lower conjunctival cul-de-sac or on the inner canthus with eyes closed, followed by immediate opening of the eyes. The cycloplegic responses as well as the extent and time of maximal mydriasis did not differ significantly between the two methods. None of the parameters describing the systemic absorption of the drug differed between the treatment groups. Conventionally applied drops caused slightly longer subjective discomfort. Instilling eyedrops on the inner canthus with eyes closed is an alternative method to deliver ocular Cyclopentolate with similar efficacy and safety as the conventional technique. This method could be useful especially when treating non-cooperative children.
-
plasma concentrations and ocular effects of Cyclopentolate after ocular application of three formulations
British Journal of Clinical Pharmacology, 1993Co-Authors: K Lahdes, Risto Huupponen, Timo Kaila, Mf Saettone, Daniela Monti, Lotta SalminenAbstract:1. Eight volunteers received in randomized order two 30 microliters drops of either 1% w/v Cyclopentolate hydrochloride or a corresponding amount of Cyclopentolate polygalacturonate in saline or in acetate buffer in one eye. Cyclopentolate concentrations in plasma were measured by a radioreceptor assay. 2. Peak plasma drug concentrations of about 3 ng ml-1 occurred within 30 min after all formulations. Occasionally, a second concentration peak in plasma, probably reflecting drug absorption from the gastrointestinal tract, was seen after 2 h. The mean elimination half-life of Cyclopentolate was 111 min when all subjects and formulations were considered together. There were no statistically significant differences between the formulations with respect to the time-course of plasma drug concentration. 3. The maximal mydriatic effect was reached within about 15 min and was maintained for several hours, often being 1/3 of its peak value after 30 h. Similarly, an intense cycloplegic response was achieved within a few minutes, the peak changes in the near-point of vision being 9 to 10 dioptres. The cycloplegic response was more intense after one of the polygalacturonate complexes, especially at later time points.
-
systemic absorption of ocular Cyclopentolate in children
German journal of ophthalmology, 1992Co-Authors: K Lahdes, Risto Huupponen, Timo Kaila, T Alimelkkila, L Salminen, M SaariAbstract:: Cyclopentolate plasma levels were quantitated and heart rate and pupil size were monitored after ocular application of the drug to juveniles. In all, 12 children were given one 35-microliters eyedrop of either 1% Cyclopentolate (n = 6) or placebo (n = 6) in randomized order in the lower cul-de-sac of one eye. A sensitive radioreceptor assay was used to determine the systemic drug absorption. With the exception of one child, detectable Cyclopentolate concentrations were seen in plasma at as early as 3 min after the ocular drug application. There was a marked interindividual variation in peak plasma Cyclopentolate concentrations ranging from undetectably low to 5.8 ng/ml (median, 2.9 ng/ml). In some children a second drug concentration peak was detected. Cyclopentolate increased the pupillary diameter from 4.8 +/- 1 mm before drug application to 8 +/- 0.9 mm at 30 min after administration, but the children's heart rate did not alter.
