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Vincent RA, Vincent SJ. You've got to hide your myopia away: John Lennon's contact lenses. Ophthalmic Physiol Opt 2024. [PMID: 39031707 DOI: 10.1111/opo.13351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 07/22/2024]
Abstract
John Lennon has an enduring, instantly recognisable, iconic, spectacle look. However, prior to 1966, he was rarely seen wearing glasses in public. From ages 7 to 26, he effectively hid his myopia away, including a period of unsuccessful contact lens wear during Beatlemania. This narrative review examines John's experience with contact lenses from 1963 to 1966 when he wore corneal rigid lenses made from polymethylmethacrylate, which regularly fell out. This frequent lens ejection was most likely due to the interaction between his upper eyelid and a spherical back surface rigid lens fitted to his right eye, which had a moderate degree of with-the-rule corneal astigmatism. John's recollection that his contact lenses stayed in place while 'stoned' supports this hypothesis, as a cannabis-induced upper eyelid ptosis would reduce the likelihood of lens ejection.
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Affiliation(s)
| | - Stephen J Vincent
- Centre for Vision and Eye Research, Optometry and Vision Science, Queensland University of Technology, Brisbane, Queensland, Australia
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Manning B, Downey LA, Narayan A, Hayley AC. A systematic review of oculomotor deficits associated with acute and chronic cannabis use. Addict Biol 2024; 29:e13359. [PMID: 38221807 PMCID: PMC10898834 DOI: 10.1111/adb.13359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 09/29/2023] [Accepted: 11/17/2023] [Indexed: 01/16/2024]
Abstract
Driving is a critical everyday task necessitating the rapid and seamless integration of dynamic visually derived information to guide neurobehaviour. Biological markers are frequently employed to detect Δ9-tetrahydrocannabinol (THC) consumption among drivers during roadside tests, despite not necessarily indicating impairment. Characterising THC-specific alterations to oculomotor behaviour may offer a more sensitive measure for indexing drug-related impairment, necessitating discrimination between acute THC effects, chronic use and potential tolerance effects. The present review aims to synthesise current evidence on the acute and chronic effects of THC on driving-relevant oculomotor behaviour. The review was prospectively registered (10.17605/OSF.IO/A4H9W), and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines informed reporting standards. Overall, 20 included articles comprising 12 experimental acute dosing trials, 5 cross-sectional chronic use studies and 3 roadside epidemiological studies examined the effects of cannabis/THC on oculomotor parameters including saccadic activity gaze behaviour, nystagmus, smooth pursuit and eyelid/blink characteristics. Acute THC consumption selectively impacts oculomotor control, notably increasing saccadic latency and inaccuracy and impairing inhibitory control. Chronic cannabis users, especially those with early age of use onset, display enduring oculomotor deficits that affect visual scanning efficiency. The presence of eyelid tremors appears to be a reliable indicator of cannabis consumption while remaining distinct from direct impairment associated with visual attention and motor control. Cannabis selectively influences oculomotor activity relevant to driving, highlighting the role of cannabinoid systems in these processes. Defining cannabis/THC-specific changes in oculomotor control may enhance the precision of roadside impairment assessments and vehicle safety systems to detect drug-related impairment and assess driving fitness.
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Affiliation(s)
- Brooke Manning
- Centre for Mental Health and Brain Science, School of Health SciencesSwinburne University of TechnologyHawthornVictoriaAustralia
- International Council for Alcohol, Drugs and Traffic Safety (ICADTS)RotterdamNetherlands
| | - Luke A. Downey
- Centre for Mental Health and Brain Science, School of Health SciencesSwinburne University of TechnologyHawthornVictoriaAustralia
- Institute for Breathing and SleepAustin HospitalMelbourneVictoriaAustralia
| | - Andrea Narayan
- Centre for Mental Health and Brain Science, School of Health SciencesSwinburne University of TechnologyHawthornVictoriaAustralia
| | - Amie C. Hayley
- Centre for Mental Health and Brain Science, School of Health SciencesSwinburne University of TechnologyHawthornVictoriaAustralia
- International Council for Alcohol, Drugs and Traffic Safety (ICADTS)RotterdamNetherlands
- Institute for Breathing and SleepAustin HospitalMelbourneVictoriaAustralia
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Wang GS, Kosnett M, Subramanian P, Wrobel J, Ma M, Brown T, Bidwell LC, Brooks-Russell A. Accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking. Clin Toxicol (Phila) 2024; 62:10-18. [PMID: 38421358 PMCID: PMC11019859 DOI: 10.1080/15563650.2024.2310154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/19/2024] [Indexed: 03/02/2024]
Abstract
INTRODUCTION Cannabis intoxication may increase the risk of motor vehicle crashes. However, reliable methods of assessing cannabis intoxication are limited. The presence of eyelid tremors is among the signs of cannabis use identified under the Drug Evaluation and Classification Program of the International Association of Chiefs of Police. Our objectives were to assess the accuracy and replicability of identifying eyelid tremor as an indicator of recent cannabis smoking using a blinded, controlled study design. METHODS Adult subjects (N = 103) were recruited into three groups based on their cannabis use history: daily, occasional, and no current cannabis use. Participants' closed eyelids were video recorded for 30 seconds by infrared videography goggles before and at a mean ± standard deviation time of 71.4 ± 4.6 minutes after the onset of a 15-minute interval of ad libitum cannabis flower smoking or vaping. Three observers with expertise in neuro-ophthalmology and medical toxicology were trained on exemplar videos of eyelids to reach a consensus on how to grade eyelid tremor. Without knowledge of subjects' cannabis use history or time point (pre- or post-smoking), observers reviewed each video for eyelid tremor graded as absent, slight, moderate, or severe. During subsequent data analysis, this score was further dichotomized as a consensus score of absent (absent/slight) or present (moderate/severe). RESULTS Kappa and intraclass correlation coefficient statistics demonstrated moderate agreement among the coders, which ranged from 0.44-0.45 and 0.58-0.61, respectively. There was no significant association between recent cannabis use and the observers' consensus assessment that eyelid tremor was present, and cannabis users were less likely to have tremors (odds ratio: 0.75; 95 percent confidence interval: 0.25, 2.40). The assessment of eyelid tremor as an indicator of recent cannabis smoking had a sensitivity of 0.86, specificity of 0.18, and accuracy of 0.64. DISCUSSION Eyelid tremor has fair sensitivity but poor specificity and accuracy for identification of recent cannabis use. Inter-rater reliability for assessment of eyelid tremor was moderate for the presence and degree of tremor. The weak association between recent cannabis use and eyelid tremor does not support its utility in identifying recent cannabis use. LIMITATIONS Videos were recorded at only one time point after cannabis use. Adherence to abstinence could not be strictly supervised. Due to regulatory restrictions, we were unable to control the cannabis product used or administer a fixed Δ9-tetrahydrocannabinol dose. Participants were predominately non-Hispanic and White. CONCLUSIONS In a cohort of participants with a range of cannabis use histories, acute cannabis smoking was not associated with the presence of eyelid tremor, regardless of cannabis use history, at 70 minutes post-smoking. Additional research is needed to identify the presence of eyelid tremor accurately, determine the relationship between cannabis dose and timeline in relation to last cannabis use to eyelid tremor, and determine how it should be, if at all, utilized for cannabis Drug Recognition Evaluator examinations.
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Affiliation(s)
- George Sam Wang
- University of Colorado Anschutz Medical Campus, Children's Hospital Colorado, Aurora, CO, USA
| | - Michael Kosnett
- University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Prem Subramanian
- Departments of Ophthalmology, Neurology, and Neurosurgery, Sue Anschutz-Rodgers University of Colorado Eye Center, Aurora, CO, USA
| | - Julia Wrobel
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA, USA
| | - Ming Ma
- Department of Biostatistics, Medpace, Denver, CO, USA
| | - Tim Brown
- Driving Safety Research Institute, College of Engineering, University of Iowa, Iowa City, Iowa, USA
| | - L Cinnamon Bidwell
- Institute of Cognitive Science, University of Colorado Boulder, Boulder, CO, USA
| | - Ashley Brooks-Russell
- Injury and Violence Prevention Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
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Tran VN, Strnad O, Šuman J, Veverková T, Sukupová A, Cejnar P, Hynek R, Kronusová O, Šach J, Kaštánek P, Ruml T, Viktorová J. Cannabidiol nanoemulsion for eye treatment - Anti-inflammatory, wound healing activity and its bioavailability using in vitro human corneal substitute. Int J Pharm 2023; 643:123202. [PMID: 37406946 DOI: 10.1016/j.ijpharm.2023.123202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 06/29/2023] [Accepted: 07/02/2023] [Indexed: 07/07/2023]
Abstract
Cannabidiol (CBD) is the non-psychoactive component of the plant Cannabis sativa (L.) that has great anti-inflammatory benefits and wound healing effects. However, its high lipophilicity, chemical instability, and extensive metabolism impair its bioavailability and clinical use. Here, we report on the preparation of a human cornea substitute in vitro and validate this substitute for the evaluation of drug penetration. CBD nanoemulsion was developed and evaluated for stability and biological activity. The physicochemical properties of CBD nanoemulsion were maintained during storage for 90 days under room conditions. In the scratch assay, nanoformulation showed significantly ameliorated wound closure rates compared to the control and pure CBD. Due to the lower cytotoxicity of nanoformulated CBD, a higher anti-inflammatory activity was demonstrated. Neither nanoemulsion nor pure CBD can penetrate the cornea after the four-hour apical treatment. For nanoemulsion, 94 % of the initial amount of CBD remained in the apical compartment while only 54 % of the original amount of pure CBD was detected in the apical medium, and 7 % in the cornea, the rest was most likely metabolized. In summary, the nanoemulsion developed in this study enhanced the stability and biological activity of CBD.
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Affiliation(s)
- Van Nguyen Tran
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Ondřej Strnad
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Jáchym Šuman
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Tereza Veverková
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Adéla Sukupová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Pavel Cejnar
- Department of Mathematics, Informatics and Cybernetics, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Radovan Hynek
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Olga Kronusová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic; EcoFuel Laboratories Ltd., Ocelářská 392, 190 00 Prague 9, Czech Republic
| | - Josef Šach
- Department of Pathology, Third Faculty of Medicine, Teaching Hospital Královské Vinohrady Prague, Šrobárova 50, 100 34 Prague 10, Czech Republic
| | - Petr Kaštánek
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic; EcoFuel Laboratories Ltd., Ocelářská 392, 190 00 Prague 9, Czech Republic
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic
| | - Jitka Viktorová
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Technicka 3, 16628 Prague 6, Czech Republic.
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Manning B, Hayley AC, Catchlove S, Shiferaw B, Stough C, Downey LA. Effect of CannEpil ® on simulated driving performance and co-monitoring of ocular activity: A randomised controlled trial. J Psychopharmacol 2023; 37:472-483. [PMID: 37129083 PMCID: PMC10184186 DOI: 10.1177/02698811231170360] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND Medicinal cannabis products containing Δ9-tetrahydrocannabinol (THC) are increasingly accessible. Yet, policy guidelines regarding fitness to drive are lacking, and cannabinoid-specific indexations of impairment are underdeveloped. AIMS To determine the impact of a standardised 1 mL sublingual dose of CannEpil®, a medicinal cannabis oil containing 100 mg cannabidiol (CBD) and 5 mg THC on simulated driving performance, relative to placebo and whether variations in vehicle control can be indexed by ocular activity. METHODS A double-blind, within-subjects, randomised, placebo-controlled, crossover trial assessed 31 healthy fully licensed drivers (15 male, 16 female) aged between 21 and 58 years (M = 38.0, SD = 10.78). Standard deviation of lateral position (SDLP), standard deviation of speed (SDS) and steering variability were assessed over time and as a function of treatment during a 40 min simulated drive, with oculomotor parameters assessed simultaneously. Oral fluid and plasma were collected at 30 min and 2.5 h. RESULTS CannEpil did not significantly alter SDLP across the full drive, although increased SDLP was observed between 20 and 30 min (p < 0.05). CannEpil increased SDS across the full drive (p < 0.05), with variance greatest at 20-30 min (p < 0.001). CannEpil increased fixation duration (p < 0.05), blink rate (trend p = 0.051) and decreased blink duration (p < 0.001) during driving. No significant correlations were observed between biological matrices and performance outcomes. CONCLUSIONS CannEpil impairs select aspects of vehicle control (speed and weaving) over time. Alterations to ocular behaviour suggest that eye tracking may assist in determining cannabis-related driver impairment or intoxication. Australian and New Zealand Clinician Trials Registry, https://anzctr.org.au(ACTRN12619000932167).
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Affiliation(s)
- Brooke Manning
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Amie C Hayley
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
- International Council for Alcohol, Drugs, and Traffic Safety
- Institute for Breathing and Sleep, Austin Health, Melbourne, VIC, Australia
| | - Sarah Catchlove
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Brook Shiferaw
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
- Seeing Machines, Melbourne, VIC, Australia
| | - Con Stough
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
| | - Luke A Downey
- Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn, VIC, Australia
- Institute for Breathing and Sleep, Austin Health, Melbourne, VIC, Australia
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