Illicit drugs: Effects on eye

Driving under the influence of drugs - The failed quest of finding medical signs indicative to driving impairment

Motor vehicle accidents (MVA) are the leading cause of death in childhood and young adult age. One of the most important factors behind MVA is driving under the influence of alcohol (DUIA) and drugs (DUID). The importance of DUID is rising together with the increasing drug abuse. The legal approaches to DUID are based on impairment, impairment per se or zero tolerance. In case of impairment, the negative effect of the substance on the driving abilities has to be proven by a forensic expert, which can be challenging. This study compares the medical signs registered during blood sampling with the concentrations of substances detected by toxicological examination to find medical signs indicative of impairment. Statistical analysis did not find a correlation between substance concentration and measured parameters (pupil diameter, blood pressure and pulse rate). No connection was found between substance concentrations and the appearance of medical signs. The results indicate that pupil dilation, heart rate, and blood pressure could not be used as indicators of possible driving impairment by drugs, and no medical sign could reliably indicate the driving impairment by substances other than ethanol.

The eye in forensic practice: In the living

Eye examination plays an important role when living individuals are forensically investigated. The iris colour, retinal scans and other biometric features may be used for identification purposes while visual impairments may have legal implications in employment, driving and accidents. Ocular manifestations provide clues regarding substance abuse, poisoning and toxicity, and evidence of trauma, abuse or disease can be revealed along with psychological traits and lifestyle. Thus, the eye is a valuable tool in forensic investigations of living subjects, providing identifying characteristics along with health information. This review focuses on the medico-legal aspects of the eye's contribution when the living are subjected to forensic examination.

Association of mild traumatic brain injury, post-traumatic stress disorder, and other comorbidities on photosensitivity

SIGNIFICANCE

Photosensitivity is common after mild traumatic brain injury. However, this study demonstrates that photosensitivity is also impacted by common comorbidities that often occur with mild traumatic brain injury. Understanding how physical and psychological traumas impact photosensitivity can help improve provider care to trauma survivors and guide novel therapeutic interventions.

PURPOSE

This study aimed to characterize the association between mild traumatic brain injury and common comorbidities on photosensitivity in post-9/11 veterans.

METHODS

Existing data from the Translational Research Center for TBI and Stress Disorders cohort study were analyzed including traumatic brain injury history and post-traumatic stress disorder clinical diagnostic interviews; sleep quality, anxiety, and depression symptoms self-report questionnaires; and photosensitivity severity self-report from the Neurobehavioral Symptom Inventory. Analysis of covariance and multiple ordinal regression models were used to assess associations between mild traumatic brain injury and common comorbidities with photosensitivity severity.

RESULTS

Six hundred forty-one post-9/11 veterans were included in this study. An initial analysis showed that both mild traumatic brain injury and current post-traumatic stress disorder diagnosis were independently associated with higher photosensitivity ratings compared with veterans without either condition, with no interaction observed between these two conditions. Results of the ordinal regression models demonstrated positive associations between degree of photosensitivity and the number of mild traumatic brain injuries during military service and current post-traumatic stress disorder symptom severity, particularly hyperarousal symptoms, even when controlling for other factors. In addition, the degree of sleep disturbances and current anxiety symptoms were both positively associated with photosensitivity ratings, whereas depression symptoms, age, and sex were not.

CONCLUSIONS

Repetitive mild traumatic brain injury, post-traumatic stress disorder, anxiety, and sleep disturbances were all found to significantly impact photosensitivity severity and are therefore important clinical factors that eye care providers should consider when managing veterans with a history of deployment-related trauma reporting photosensitivity symptoms.

The impact of Alzheimer's disease risk factors on the pupillary light response

Alzheimer's disease (AD) is the leading cause of dementia, and its prevalence is increasing and is expected to continue to increase over the next few decades. Because of this, there is an urgent requirement to determine a way to diagnose the disease, and to target interventions to delay and ideally stop the onset of symptoms, specifically those impacting cognition and daily livelihood. The pupillary light response (PLR) is controlled by the sympathetic and parasympathetic branches of the autonomic nervous system, and impairments to the pupillary light response (PLR) have been related to AD. However, most of these studies that assess the PLR occur in patients who have already been diagnosed with AD, rather than those who are at a higher risk for the disease but without a diagnosis. Determining whether the PLR is similarly impaired in subjects before an AD diagnosis is made and before cognitive symptoms of the disease begin, is an important step before using the PLR as a diagnostic tool. Specifically, identifying whether the PLR is impaired in specific at-risk groups, considering both genetic and non-genetic risk factors, is imperative. It is possible that the PLR may be impaired in association with some risk factors but not others, potentially indicating different pathways to neurodegeneration that could be distinguished using PLR. In this work, we review the most common genetic and lifestyle-based risk factors for AD and identify established relationships between these risk factors and the PLR. The evidence here shows that many AD risk factors, including traumatic brain injury, ocular and intracranial hypertension, alcohol consumption, depression, and diabetes, are directly related to changes in the PLR. Other risk factors currently lack sufficient literature to make any conclusions relating directly to the PLR but have shown links to impairments in the parasympathetic nervous system; further research should be conducted in these risk factors and their relation to the PLR.

Epidemiology and factors associated with cannabis use among patients with glaucoma in the All of Us Research Program

Purpose

To examine the epidemiology and factors of cannabis use among open-angle glaucoma (OAG) patients.

Methods

In this cross-sectional study, OAG participants in the All of Us database were included. Cannabis ever-users were defined based on record of cannabis use. Demographic and socioeconomic data were collected and compared between cannabis ever-users and never-users using Chi-Square tests and logistic regression. Odds ratios (OR) of potential factors associated with cannabis use were examined in univariable and multivariable models.

Results

Among 3723 OAG participants, 1436 (39%) were cannabis ever-users. The mean (SD) age of never-users and ever-users was 72.9 (10.4) and 69.2 (9.6) years, respectively (P < 0.001). Compared to never-users, Black (34%) and male (55%) participants were better represented in ever-users, while Hispanic or Latino participants (6%) were less represented (P < 0.001). Diversity was also observed in socioeconomic characteristics including marital status, housing security, and income/education levels. A higher percentage of ever-users had a degree ≥12 grades (91%), salaried employment (26%), housing insecurity (12%), and history of cigar smoking (48%), alcohol consumption (96%), and other substance use (47%) (P < 0.001). In the multivariable analysis, Black race (OR [95% CI] = 1.33 [1.06, 1.68]), higher education (OR = 1.19 [1.07, 1.32]), and history of nicotine product smoking (OR: 2.04-2.83), other substance use (OR = 8.14 [6.63, 10.04]), and alcohol consumption (OR = 6.80 [4.45, 10.79]) were significant factors associated with cannabis use. Increased age (OR = 0.96 [0.95, 0.97]), Asian race (OR = 0.18 [0.09, 0.33]), and Hispanic/Latino ethnicity (OR = 0.43 [0.27, 0.68]) were associated with decreased odds of use (P < 0.02).

Conclusions

This study elucidated the previously uncharacterized epidemiology and factors associated with cannabis use among OAG patients, which may help to identify patients requiring additional outreach on unsupervised marijuana use.

TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface

Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.

Challenges and future trends in wearable closed-loop neuromodulation to efficiently treat methamphetamine addiction

Achieving abstinence from drugs is a long journey and can be particularly challenging in the case of methamphetamine, which has a higher relapse rate than other drugs. Therefore, real-time monitoring of patients' physiological conditions before and when cravings arise to reduce the chance of relapse might help to improve clinical outcomes. Conventional treatments, such as behavior therapy and peer support, often cannot provide timely intervention, reducing the efficiency of these therapies. To more effectively treat methamphetamine addiction in real-time, we propose an intelligent closed-loop transcranial magnetic stimulation (TMS) neuromodulation system based on multimodal electroencephalogram-functional near-infrared spectroscopy (EEG-fNIRS) measurements. This review summarizes the essential modules required for a wearable system to treat addiction efficiently. First, the advantages of neuroimaging over conventional techniques such as analysis of sweat, saliva, or urine for addiction detection are discussed. The knowledge to implement wearable, compact, and user-friendly closed-loop systems with EEG and fNIRS are reviewed. The features of EEG and fNIRS signals in patients with methamphetamine use disorder are summarized. EEG biomarkers are categorized into frequency and time domain and topography-related parameters, whereas for fNIRS, hemoglobin concentration variation and functional connectivity of cortices are described. Following this, the applications of two commonly used neuromodulation technologies, transcranial direct current stimulation and TMS, in patients with methamphetamine use disorder are introduced. The challenges of implementing intelligent closed-loop TMS modulation based on multimodal EEG-fNIRS are summarized, followed by a discussion of potential research directions and the promising future of this approach, including potential applications to other substance use disorders.

Bilateral mydriasis as first manifestation of Hodgkin's lymphoma: a case report

BACKGROUND

Bilateral mydriasis is usually associated with severe brain stem damage or drug-induced sympathomimetic stimulation. Herein we report it as a unique neurologic complication of Hodgkin's lymphoma.

CASE PRESENTATION

A 23-year-old woman presented at our emergency department with dilated pupils unresponsive to light stimuli. MRI and CT scans showed bilaterally enlarged lymph nodes in the mediastinum and supraclavicular compressing the carotid artery on both sides. The histologic examination of lymph node biopsy specimens confirmed the diagnosis of Hodgkin's lymphoma.

CONCLUSION

Pathologies around the carotid artery causing oculosympathetic spasm should be considered among the possible causes of a mydriasis, especially when other common causes like brain stem impairment are excluded.

The adaptive significance of human scleral brightness: an experimental study

Homogeneously depigmented sclerae have long been proposed to be uniquely human-an adaptation to enable cooperative behaviour by facilitating interpersonal coordination through gaze following. However, recent evidence has shown that deeply pigmented sclerae also afford gaze following if surrounding a bright iris. Furthermore, while current scleral depigmentation is clearly adaptive in modern humans, it is less clear how the evolutionarily intermediate stages of scleral pigmentation may have been adaptive. In sum, it is unclear why scleral depigmentation became the norm in humans, while not so in sister species like chimpanzees, or why some extant species display intermediate degrees of pigmentation (as our ancestors presumably did at some point). We created realistic facial images of 20 individually distinct hominins with diverse facial morphologies, each face in the (i) humanlike bright sclera and (ii) generalised apelike dark sclera version. Participants in two online studies rated the bright-sclera hominins as younger, healthier, more attractive and trustworthy, but less aggressive than the dark-sclera hominins. Our results support the idea that the appearance of more depigmented sclerae promoted perceived traits that fostered trust, increasing fitness for those individuals and resulting in depigmentation as a fixed trait in extant humans.

Long-term effects of methamphetamine abuse on visual evoked potentials

PURPOSE

To compare visual evoked potential (VEP) components in normal individuals and those with long-term methamphetamine and crystal methamphetamine use.

METHODS

In this study, monocular pattern-reversal VEPs were recorded in 40 methamphetamine and crystal methamphetamine users and 38 normal individuals. Visual stimuli were high-contrast (99%) checkerboard patterns at 15 and 60 min of arc with a reversal rate of 1.53 reversals per second.

RESULTS

A significant difference was seen between the two groups for the P100 peak time for the 60 min of arc checks (p = 0.002, d = 0.75, 4.61% higher peak time in the addicted group) and the 15 min of arc checks (p = 0.004, d = 0.73, 4.78% higher peak time in the addicted group). However, other VEP components were not significantly different between the two groups.

CONCLUSIONS

The higher P100 peak time at both 15 and 60 min of arc in methamphetamine-dependent users reveals that VEPs are highly sensitive for the diagnosis of retinal and visual pathway lesions.

A Review of Ocular Complications Associated with Medications Used for Anxiety, Depression, and Stress

This review of commonly prescribed psychotropic drugs aims to update the clinician on possible ophthalmic side effects that may include dry eye, diplopia, mydriasis, and cataracts. This review summarizes our current knowledge of known ocular side effects of psychotropic drugs based on reviews, case reports, case-control studies, a case series, and cross-sectional observational studies reported in the recent literature. The review covers disorders related to depression, anxiety, and stress which are commonly encountered within society and can have debilitating impacts on an individual's quality of life that may require chronic therapeutic management. The main medications used in the treatment and management of these conditions typically target receptors, metabolic enzymes, or transport pumps that alter the pre- and/or post-synaptic levels of neurotransmitters such as serotonin, norepinephrine, dopamine, gamma-aminobutyric acid, and opioids to improve mood and/or relieve pain and anxiety. Novel non-therapeutic options are undergoing clinical trials, and some patients may seek alternative therapies or have associated substance abuse issues to alleviate their symptoms. This review summarizes some of the clinical signs of depression and the main therapeutic options and their reported ocular side effects which may be pertinent today given the rise in use of psychotropic medications used to manage depression, anxiety, and stress.

Changes in corneal and anterior chamber indices due to methamphetamine abuse

CLINICAL RELEVANCE

Considering the significant relationship between methamphetamine abuse and some anterior segment indices, methamphetamine abuse should be considered in differential diagnosis especially in the case of angle closure glaucoma.

BACKGROUND

To investigate the effect of inhaled methamphetamine (meth) and crystal methamphetamine (crystal meth) on the quantitative indices of the cornea and anterior chamber using pentacam and anterior segment optical coherence tomography.

METHODS

In this cross-sectional study, the participants were (crystal) meth addicts living in Zahedan. The participants were transported to the examination site to undergo imaging and optometric tests. Pentacam and anterior segment optical coherence tomography imaging were then conducted so as to evaluate corneal and anterior chamber quantitative indices.

RESULTS

A total of 42 (crystal) meth addicts and 42 healthy subjects with matching age and gender were examined. Out of 42 subjects in the case group, 6 were female and 36 were male (mean age: 35.7 ± 8.6 years). The mean dose of drug used was 0.0074 ± 0.0034 g, and the mean duration of drug use was 6.9 ± 2.6 years (5-12 years). Based on the images of both devices, corneal curvature was significantly steeper in both meridians of anterior and posterior surfaces compared to the control group (p = 0.01). Among the anterior chamber parameters, the anterior chamber depth and volume were lower in the cases than the controls (p < 0.01). However, the lens rise was higher in addicts than controls (p = 0.01).

CONCLUSION

Quantitative changes in corneal and anterior segment indices including dilated pupils, shallower anterior chamber depth and higher lens rise in addicted cases compared to the control group may precipitate the risk of closed-angle in these individuals.

Accommodative and convergence anomalies in patients with opioid use disorder

Clinical relevance: Considering the significant relationship between opioid abuse and some accommodative and convergence disorders, opioid use should be considered in the differential diagnosis and will directly affect the management plan.Background: To determine the prevalence of accommodative and convergence anomalies and their related factors in a population of male young adults with opioid use disorder (OUD).Methods: This cross-sectional study was conducted using a convenience sampling method in 2019. The study sample included male young adults with OUD who had been referred to a specialised drug-dependence rehabilitation centre in Mashhad, Iran. The diagnosis of OUD was made by a psychologist based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. All patients underwent complete optometric examinations.Results: Eighty male young adults with OUD were included in this study. The mean age of participants was 30.5 ± 3.9 years (age range 19 to 35 years). The prevalence of accommodative and convergence disorders was 33.75% (95% CI: 23.55-45.19) and 25.00 (95% CI: 15.99-35.94), respectively. Accommodative insufficiency (22.5%, 95% CI: 13.91-33.21) had a higher prevalence than accommodative excess (3.75%, 95% CI: 0.78-10.57) and accommodative infacility (7.50%, 95% CI: 2.80-15.61). Convergence insufficiency (18.75%, 95% CI: 10.89-29.03) had a higher prevalence compared to convergence excess (3.75%, 95% CI: 0.78-10.57) and basic exophoria (2.50%, 95% CI: 0.30-8.74). According to the multiple logistic regression, a significant inverse relationship was observed between pupil size with accommodative insufficiency (OR = 0.45), accommodative infacility (OR = 0.67), and convergence insufficiency (OR = 0.55).Conclusion: The results of the present study showed a higher prevalence of some accommodative and convergence disorders in OUD patients compared to the prevalence reported in previous studies conducted on the normal populations with a similar age range.

Macular hemorrhage after laser exposure and cannabinoid intake during a disco party

Purpose

To describe two cases of macular hemorrhage in young patients, both occurred after laser exposure and cannabinoid intake during a disco party.

Observations

Case 1: a 21-year-old man was evaluated at our Emergency Unit for sudden vision loss in the right eye (RE). Best-corrected visual acuity (BCVA) was count fingers in the RE and 20/20 in the left eye (LE). Fundus examination revealed a broad pre-retinal hemorrhage in macular region of RE, confirmed by optical coherence tomography. The patient reported vision loss, suddenly occurred after fixation of a laser source and cannabinoid intake during a disco party the night before. We administered a macular supplement and closely followed up the patient. After two months BCVA of the right eye was 20/20.

Case 2

The following day another 21-year-old man was referred to our Emergency Unit complaining of sudden vision loss in LE. As in Case 1, he reported to have fixed a laser beam as well as the consumption of cannabinoids at the same disco. BCVA was count fingers in the LE and 20/20 in the RE. Fundus examination showed a broad pre-retinal hemorrhage in macular region of LE. He had taken the macular supplement for two months and then the hemorrhage was reabsorbed.

Conclusion and importance

Laser exposure must be considered as a possible cause of macular hemorrhage. Furthermore, low cost of drugs and lack of formal control of laser sources may increase the emergence of new cases of retinal injuries especially among young people.