Study on the correlation between iris blood flow, iris thickness and pupil diameter in the resting state and after pharmacological mydriasis in patients with diabetes mellitus.

BACKGROUND: To investigate whether iris blood flow and iris thickness at the iris smooth muscle region affect the pupil diameter at rest and after drug-induced mydriasis in patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). METHODS: T1DM patients and healthy children were recruited from the SCADE cohort. T2DM patients and healthy adults were recruited from patients undergoing cataract surgery at Shanghai General Hospital. Iris vessel density, pupil diameter (PD) and iris thickness were measured in both the resting and drug-induced mydriasis states. Iris vessel density was measured by optical coherence tomography angiography (OCTA), PD was measured by a pupilometer, and iris thickness at the iris smooth muscle regions were measured using anterior segment optical coherence tomography (AS-OCT). RESULTS: The study included 34 pediatric T1DM patients and 50 adult T2DM patients, both groups without diabetic retinopathy, and age-sex-matched healthy controls. At baseline, T1DM children and healthy children showed no differences in iris blood flow, iris thickness, or PD. However, the adult T2DM group exhibited higher vessel density at the pupil margin, thinner iris thickness at the iris dilator region, and smaller PD compared to healthy adults, with these differences being statistically significant (P < 0.05). After pupil dilation, there were no changes in iris blood flow and PD in the T1DM group compared to healthy children, whereas the T2DM group showed a significantly smaller PD compared to healthy adults. Multivariate regression analysis revealed that in the T2DM group, glycated hemoglobin was an independent factor of PD after dilation (ß=-0.490, p = 0.031), with no such factors identified in the T1DM group. CONCLUSION: The insufficiently dilated pupil diameter after drug-induced mydriasis is correlated to the level of glycated hemoglobin among T2DM patients. TRIAL REGISTRATION: The registration number on the clinical trial website was NCT03631108.

Unveiling the Dark Side of Datura in Pediatric Poisoning With Insights From Jordanian Experience : A Retrospective Clinical Study.

OBJECTIVES: Datura stramonium , jimsonweed, is a toxic plant with hallucinogenic properties. Although there are many studies on Datura poisoning, none reported cases in Jordan. This study offers a comprehensive review on D. stramonium ingestion, covering its epidemiology, clinical presentation, and treatment. We aimed to provide better understanding of the factors for Datura ingestion, identify prevention and management strategies, and address research challenges. METHODS: This study adopted a retrospective review design to evaluate the cases of Datura poisoning in Al Karak, province of Jordan during the spring of 2022. Data collected from medical records, toxicology databases, and consultation records were analyzed using descriptive statistics. RESULTS: The common symptoms of Datura poisoning included agitation, mydriasis, and tachycardia. The management approaches comprised supportive care, administration of Diazepam for agitation, and, in some cases, neostigmine to counteract anticholinergic effects. CONCLUSIONS: Understanding the risks associated with D. stramonium poisoning and implementing effective prevention and management strategies are crucial. This study highlights the importance of recognizing Datura poisoning as a potential diagnosis in children presenting with unexplained anticholinergic symptoms or agitation to the emergency room.

Neonatal diagnosis of ACTA2-related disease: A case report and review of literature.

Multisystemic smooth muscle dysfunction syndrome (MSMDS, OMIM # 613834) is a rare autosomal dominant condition caused by pathogenetic variants of ACTA2 gene that result in impaired muscle contraction. MSMDS is characterized by an increased susceptibility to aneurismal dilatations and dissections, patent ductus arteriosus, early onset coronary artery disease, congenital mydriasis, chronic interstitial lung disease, hypoperistalsis, hydrops of gall bladder, and hypotonic bladder. Here, we report an early diagnosis of a MSMDS related to ACTA2 p.Arg179His (R179H) mutation in a newborn and performed a review of the literature. An early diagnosis of MSMDS is extremely important, because of the severe involvement of cardiovascular system in the MSMDS. Multidisciplinary care and surveillance and timely management of symptoms are important to reduce the risk of complications.

Light- and drug-induced pupillary dynamics in eyes with a retropupillary iris-claw intraocular lens.

PURPOSE: We evaluated the pupillary characteristics and response to light and drugs in eyes with posterior chamber (PC) placement of iris-claw intraocular lens (IC-IOL). METHODS: In this cross-sectional, comparative study, we included adults with an IC-IOL implanted in the PC of a single eye. We excluded patients with ocular trauma, postoperative IC-IOL displacement or complications, and extended iris atrophy. We used anterior segment optical coherence tomography to perform light-controlled pupillography, measure the pupil diameter (PD), and estimated the pupil circularity under mesopic conditions. PD was also assessed under photopic, scotopic, pharmacological mydriasis, and miosis conditions. The results were compared to those of the fellow eye, phakic, or regular pseudophakic. RESULTS: The IC-IOL and control groups included 30 eyes each. The most frequent reasons for IC-IOL implantation were complicated cataract (37%) and dislocated/luxated prior IOL (33%). Compared to the control group, the IC-IOL group had lower visual acuity, a smaller PD under scotopic conditions (p = 0.0010) and after pharmacological mydriasis (p < 0.0001), and a larger PD after pharmacological miosis (p < 0.0001). Mesopic pupil circularity was comparable between the groups. We also considered ongoing extraocular treatments with possible effects on iris motility. CONCLUSIONS: The pupillary size and profile were similar between the groups in mesopic light. Reduced mydriasis was noted in response to light and drugs, while the degree of miosis was reduced in response to inducing drugs in the IC-IOL compared to the control group. This study complements previous results concerning the PC placement of IC-IOLs by adding original observations on drug-induced pupil motility.

Single­pass four­throw versus traditional knotting pupilloplasty for traumatic mydriasis combined with lens dislocation.

PURPOSE: To compare the use of single­pass four­throw (SFT) and traditional double-pass two-throw knotting (DTT) techniques in pupilloplasty for traumatic mydriasis combined with lens dislocation, and to evaluate the learning curve between the two knotting techniques by wet lab. METHOD: The eyes of 45 patients (45 eyes) were divided into two groups according to the knotting technique used: single­pass four­throw (22 eyes) or traditional double-pass-two-throw knotting (23 eyes). Combined phacoemulsification and pupilloplasty with pars plana vitrectomy were performed in traumatic mydriasis patients with lens dislocation. Preoperative and postoperative corrected distance visual acuity (CDVA), pupil diameter, intraocular pressure (IOP), pupilloplasty time, and complications were compared. Twenty ophthalmology residents were randomized to perform a pupilloplasty suturing exam with or without SFT knotting techniques in porcine eyes. RESULT: All cases had a minimum follow­up period of 6 months (range 6-12 months). There was no significant difference in the CDVA (P = 0.55), postoperative pupil diameter (P = 0.79), IOP (P > 0.05), anterior chamber exudate degree, and loosening or shedding of the line knot between the two groups. The duration of the pupilloplasty was 22.32 ± 4.58 min in the SFT group and 30.35 ± 5.55 min in the traditional group, which was a significant difference (P < 0.01). The residents in the SFT group had higher test scores and fewer surgical mistakes (P < 0.05). CONCLUSION: The SFT knotting technique has a similar treatment effect and safety as the traditional technique but requires a shorter time and is easier to perform in pupilloplasty surgery.

Evaluating Changes in Apparent Chord Mu after Pharmacological Pupil Dilatation.

INTRODUCTION: Preoperative measurements of apparent chord mu length above 0.6 mm have been associated with higher risks for photic phenomena after cataract surgery with multifocal intraocular lenses (MFIOLs). METHODS: This retrospective study evaluated patients scheduled for elective cataract surgery at a single tertiary medical center between 2021 and 2022. Pupil diameter and apparent chord mu length were analyzed for eyes with biometry measurements from IOLMaster 700 (Carl Zeiss Meditec, AG) under photopic light conditions, before and after pharmacological pupil dilatation. Exclusion criteria were visual acuity worse than 20/100, prior intraocular surgery, refractive surgery, iris-related procedures, or pupil abnormalities affecting dilatation. Apparent chord mu lengths before and after pupil dilatation were compared. In addition, multivariate linear regression analysis, using a stepwise method, was conducted to assess possible predictors of apparent chord values. RESULTS: Included were 87 eyes of 87 patients. Mean chord mu length increased after pupillary dilatation from 0.32 ± 0.17 mm to 0.41 ± 0.17 mm for right eyes (p < 0.001) and from 0.29 ± 0.16 mm to 0.40 ± 0.22 mm for left eyes (p < 0.001). Seven eyes (8.0%) had an apparent chord mu of 0.6 mm and above pre-dilatation. Fourteen eyes (16.1%) with an apparent chord mu under 0.6 mm pre-dilatation had apparent chord mu of 0.6 mm or above post-dilatation. CONCLUSION: Apparent chord mu length significantly increases after pharmacological pupillary dilatation. Pupil size and dilatation status should always be considered during patient selection for a planned MFIOL using apparent chord mu length as a reference marker.

Mydriasis and anisocoria in a pediatric hyperhidrosis patient with interesting findings in the family cat.

Here, we report a case of unilateral ocular mydriasis in a pediatric patient with longstanding hyperhidrosis, as well as similar findings in her cat. The patient had been undergoing treatment of her hyperhidrosis with topical glycopyrrolate. This case highlights the potential side effect profile of topical antimuscarinics and the importance of counseling patients on proper precautions.

Bilateral Transient Dilated and Fixed Pupils After Microvascular Decompression: Rare Clinical Experience.

Microvascular decompression (MVD) has a satisfactory safety, and it is the only surgical treatment for neurovascular compression diseases, such as hemifacial spasm, trigeminal neuralgia, and glossopharyngeal neuralgia, from the perspective of etiology. Bilateral dilated and fixed pupils have long been regarded as a sign of life threatening, which is common in patients with cerebral herniation due to cranial hypertension. However, transient dilated pupils after MVD have not been previously reported. Here, we presented 2 patients with bilateral transient dilated and fixed pupils after MVD and discussed the possible etiologies through the literature review. Physical examination of both patients showed bilateral pupils were normal and without a medical history of pupil dilation. They underwent MVD under general anesthesia and used propofol and sevoflurane. In both cases, the vertebral artery was displaced, and Teflon pads were inserted between the vertebral artery and the brain stem. Postoperation, we found transient bilateral mydriasis without light reflection in both patients. The emergency head computed tomography revealed no obvious signs of hemorrhage and cerebral herniation. About 1 hour later, this phenomenon disappeared. Therefore, the authors think if MVD is successfully carried out, bilateral transient mydriasis may not necessarily indicate brain stem hemorrhage, cerebral herniation, and other emergency conditions, which can be recovered within a short time. The causes could be related to stimulation of the sympathetic pathway in the brain stem during MVD and side effects of anesthetics.

Efficacy and safety of intraoperative use of tropicamide 0.02%/phenylephrine0.31%/lidocaine1% intracameral combination during pediatric cataract surgery.

BACKGROUND: To demonstrate the safety and efficacy of the intracameral use of tropicamide 0.02%/phenylephrine 0.31%/lidocaine 1% in pediatric cataract surgery, a combination widely used in adult patients but still off-label in children. METHODS: Design: two-center, prospective, observational study. SETTING: San Giuseppe Hospital, Milan and Meyer Children's Hospital, Florence. STUDY POPULATION: children from 0 to 4 years of age undergoing cataract surgery with or without intraocular IOL implantation, in the absence of clinically significant systemic conditions, history of ocular surgery, concurrent ocular medication, hypersensitivity to any of the substances and post-traumatic cataracts. During the surgery, patients received the combination drug after the primary access to the anterior chamber. Efficacy was evaluated by achieving an adequate mydriasis in order to perform capsulorhexis, while safety was assessed by recording vital signs (heart rate, blood pressure, respiratory rate, temperature) pre- and post-administration of the substance. RESULTS: This study included 53 surgical procedures of 36 patients: 41 eyes were left aphakic, while 12 eyes received primary IOL implantation. The pupil size was adequate to safely perform capsulorhexis in 52 procedures of 53. The difference in pupil enlargement was significant (6.0 ± 1.14 mm, P = < 0.001). There were no notable changes in vital parameters. CONCLUSIONS: The administration of intracameral tropicamide 0.02%/phenylephrine 0.31%/lidocaine 1% in pediatric cataract surgery is effective for obtaining an adequate mydriasis without any vital parameters changes throughout the procedure.

Clinical and neuroimaging features of a familial pathogenic ACTA2 variant as a model of a vascular neurocristopathy.

The clinical and neuroimaging findings of a family with a variant ACTA2 gene (c351C > G), presenting with smooth muscle dysfunction in structures of neural crest derivation, are discussed. The combination of aortic abnormalities, patent ductus arteriosus, congenital mydriasis and distinctive cerebrovascular and brain morphological abnormalities characterise this disorder. Two sisters, heterozygous for the variant, and their mother, a mosaic, are presented. Brain parenchymal changes are detailed for the first time in a non-Arg179His variant. Radiological features of the petrous canal and external carotid are highlighted. We explore the potential underlying biological and embryological mechanisms.

Flicker electroretinogram in newborn infants.

PURPOSE: To develop and validate a flicker electroretinogram (ERG) protocol in term-born neonates as a potential tool for assessing preterm infants at risk of developing retinopathy of prematurity. METHODS: A custom flicker ERG protocol was developed for use with the hand-held RETeval® electrophysiology device. Feasibility of measuring flicker ERG through closed eyelids and without mydriasis was established in a pilot study enabling optimisation of the test protocol. Following this, healthy term-born neonates (gestational age 37-42 weeks) were recruited at the Neonatology clinic of the University Hospital Zurich. Flicker ERG recordings were performed using proprietary disposable skin electrodes during the first four days of life when the infants were sleeping. Flicker stimuli were presented at 28.3 Hz for a stimulus series at 3, 6, 12, 30, and 50 cd·s/m2, with two measurements at each stimulus level. Results were analysed offline. Flicker ERG peak times and amplitudes were derived from the averaged measurements per stimulus level for each subject. RESULTS: 28 term-born neonates were included in the analysis. All infants tolerated the testing procedure well. Flicker ERG recording was achieved in all subjects with reproducible flicker ERG waveforms for 30 and 50 cd·s/m2 stimuli. Reproducible ERGs were recorded in the majority of infants for the weaker stimuli (with detectable ERGs in 20/28, 25/28, and 27/28 at 3, 6, and 12 cd·s/m2, respectively). Flicker ERG amplitudes increased with increasing stimulus strength, with peak times concurrently decreasing slightly. CONCLUSION: Flicker ERG recording is feasible and reliably recorded in sleeping neonates through closed eyelids using skin electrodes and without mydriasis. Flicker ERG amplitude decreases for lower luminance flicker but remains detectable for 3 cd·s/m2 flicker in the majority of healthy term-born neonates. These data provide a basis to study retinal function in premature infants using this protocol.

Comparison of different pupil dilatation methods for phacoemulsification in eyes with a small pupil.

PURPOSE: To compare 6 methods for intraoperative pupil dilatation in eyes with insufficient pupil size during phacoemulsification. METHODS: This was a prospective case-control study. 99 microcoria cataract patients (120 eyes) were collected and were divided into 6 groups(20 eyes each group), and their pupils were dilated by bimanual stretching pupil (group I), pupil radial cut open(group II), mechanical pupil dilatation with iris-retractor hooks (group III), OASIS iris expander (group IV), and Malyguin-ring (Microsurgical company, America) (group V), B-HEX Pupil Expander (Med Invent Devics, India)(group VI),respectively. 3.0 mm clear corneal incision were used in phacoemulsification. All cases were followed up at 1 week and 1, 3, 6 months after the surgery. The best corrected visual acuity (BCVA), intraocular pressure(IOP), corneal endothelium cell density(ECD), pupil diameter(PD) of before and after surgery were compared. RESULTS: One same doctor finished all cataract surgeries successfully. The eyes' condition before surgery and at 6 months after surgery were compared. There were no significant statistical differences for the conditions of the eyes before surgery among six groups. The ECDs were better at 6 months postoperatively in group III and V, median values: 2114/mm2, 1961/mm2. PD was largest in group II (median value: 5.5 mm), which was significantly larger than other groups (Padjusted < 0.05). CONCLUSIONS: All 6 methods used in this study were effective for the mechanical dilatation of small pupils and didn't affect the postoperative visual acuity and intraocular pressure in microcoria cataract phacoemulsification. Iris-retractor hooks and the Malyugin Ring can reduce intraoperative corneal endothelium cell loss. Postoperative PD is larger when the iris was cut open radially.

Pharmacologic Mydriasis Secondary to Topical Glycopyrronium Tosylate Cloths: Clinical Characterization From a Multicenter Analysis.

BACKGROUND: Topical glycopyrronium tosylate (GT) is an anticholinergic medication for treatment of axillary hyperhidrosis. Pharmacologic mydriasis and anisocoria from topical GT has been reported and may be underrecognized. This study aims to clinically characterize patients presenting with pharmacologic mydriasis from exposure to this medication. METHODS: This study is a retrospective observational case series. A multicenter chart review of 16 patients diagnosed with pharmacologic mydriasis secondary to topical GT was performed. RESULTS: Eight patients (50.0%) were age 18 years and younger, and 14 patients (87.5%) were female. Unilateral mydriasis (anisocoria) occurred in 14 patients (87.5%). Fourteen patients (87.5%) did not initially volunteer topical GT as a "medication," and the history of topical GT exposure needed to be elicited with further questioning. Hand hygiene details were known for 12 patients, and all reported that they did not wash their hands after GT application. Six patients (37.5%) were soft contact lens users. One patient had possible exposure through a family member's use of the medication. Ocular symptoms were common (blurry vision [11 patients, 68.8%] and eye dryness [7 patients, 43.8%]), but systemic anticholinergic symptoms were uncommon (such as constipation [1 patient, 6.3%] and urinary symptoms [3 patients, 18.8%]). CONCLUSIONS: Mydriasis associated with topical GT seems to be a consequence of local exposure rather than systemic toxicity. Because patients may not volunteer topical GT as a medication, eliciting a history of exposure often requires further specific questioning. Soft contact lens wear and poor postapplication hand hygiene seem to be associated with mydriasis in GT use.

Margin of safety of extended-duration transdermal buprenorphine solution following multiple-dose administrations to cats.

Transdermal buprenorphine solution (TBS) is approved for the control of postoperative pain in cats where a single preoperative dose provides 4 days of analgesia. It is administered as a unit dose of 8 mg to cats weighing 1.2-3 kg and 20 mg to cats weighing to >3-7.5 kg, which is equivalent to a dosage on a bodyweight basis of 2.7-6.7 mg/kg. In this safety study, the 1X dose was defined as 6.7 mg/kg. Thirty-two cats (16 males and 16 females) were randomly allocated to placebo, 1, 2, and 3X TBS administered topically to the dorsal cervical skin every 4 days for 3 doses. Clinical observations, behavioral scores, mydriasis score (yes/no), and physiological variables were assessed or measured prior to each dose administration (0 h) and at 1, 2, 4, 8, 12, 24, 36, 48, and 72 h following each treatment and prior to euthanasia on Day 12 or 13. Blood samples for clinical pathology were collected on Days - 1, 4, 8, and prior to euthanasia. There was little evidence of respiratory, cardiovascular, or gastrointestinal effects. Respiratory rates were above the reference range in all groups and lower by 10 breaths/min in the 3X group during the third dosing interval compared to placebo. There were no differences in heart rates. Constipation was transiently observed in approximately equal numbers in placebo- and TBS-treated cats. Behavioral scores showed sedation or euphoria was transient in the first dosing interval but became more prolonged with each dosing interval. Mydriasis was prolonged in the first dosing interval and diminished by the third dosing interval consistent with accommodation. Mean body temperatures in TBS-treated cats were up to 0.6°C (1.8°F) greater than placebo-treated cats. There were no clinically relevant changes to serum chemistry, hematology, or urinalysis outcomes nor gross or microscopic observations attributable to TBS. These data demonstrate that TBS is safe and well-tolerated when administered to 16-week-old cats at multiples of the approved dose and duration and supports clinical safety in the event of delayed buprenorphine metabolism, medication errors, or alterations in the dosing regimen.

Triple bypass for multisystem smooth muscle dysfunction syndrome due to Arg179His ACTA2 mutation.

Missense mutations in the smooth muscle-specific isoform of the alpha-actin (ACTA2) gene, which encodes smooth muscle actin, congenitally cause systemic smooth muscle dysfunction, leading to multiple systemic smooth muscle dysfunction syndrome. This disease is often diagnosed through the development of congenital mydriasis, patent ductus arteriosus, or thoracic aortic aneurysm at a young age. Some patients develop cerebrovascular lesions, also known as ACTA2 cerebral arteriopathy, which cause ischemic stroke and require surgical revascularization. However, an effective and safe treatment has not yet been established owing to the rarity of the disease. Furthermore, most reports of this disease involve children, with only a few reports on adults and few detailed reports on treatment outcomes published to date. We report a 46-year-old woman with ACTA2 cerebral arteriopathy caused by Arg179His, the most common mutation in this disease; she is the oldest patient reported with this disease to the best of our knowledge. The patient was diagnosed with multiple systemic smooth muscle dysfunction syndrome and ACTA2 cerebral arteriopathy after experiencing a stroke in the right cingulate gyrus. She underwent direct triple bypass with three anastomoses of the right superficial temporal artery to the middle and anterior cerebral arteries. She developed an ischemic stroke as a postoperative complication.The efficacy and safety of this procedure have not been clearly confirmed owing to the frailty of the donor superficial temporal artery and the poor development of collateral circulation; however, direct bypass should be considered a treatment option for patients experiencing progressive multiple strokes.

A well-appearing infant with a sudden anisocoria.

Case presentationA 10-month-old boy was admitted to the emergency department due to a sudden onset of left unilateral mydriasis (figure 1). His medical history was unremarkable. A minor head trauma 2 days before was reported, without alarming signs or symptoms. His mother was putting him to sleep, after coming back from work, when she noticed a different pupil size and promptly went to the ED with her husband. The parents denied any use of medications, including nebulised therapy or direct contact with plants. The child was well appearing and his vital signs were within the standard age limits. His extraocular motility was normal as well as the rest of his neurological and physical examination. Parents' behaviour was somehow remarkable. Even though the child was not suffering, the mother seemed very worried while the father was nervous and aggressive, repeatedly asking for a discharge.

Ophthalmic Parameters and Ophthalmoscopy of Burrowing Owls (Athene cunicularia).

Twelve adult burrowing owls (Athene cunicularia) maintained in a managed environment underwent complete bilateral ophthalmic examinations to assess ocular parameters and, if present, describe lesions (n = 24 eyes). Tear production was measured with a Schirmer tear test (STT), and intraocular pressure (IOP) was measured with rebound tonometry using established calibration settings (D = dog/cat, P = other species). Retinography was performed for all birds after application of topical rocuronium bromide, and corneal diameter was measured. Menace response was absent bilaterally in 7 of 12 (58.3%) owls; however, this did not appear to be related to the presence of fundic lesions. Ocular lesions were visualized in 6 of 12 (50%) owls. The most common ophthalmic abnormality noted was mild multifocal fundic pigment clumping, suggestive of chorioretinal scarring. Other ocular lesions included 1 retinal tear and 1 incipient cataract. Mean tear production was 6.1 ± 3.0 mm/min. Mean IOPs were 11.6 ± 1.8 mm Hg and 7.1 ± 1.3 mm Hg for the D and P settings, respectively, and these were significantly different (P < 0.001). The IOP results did not differ significantly based on patient age or between the right and left eyes, but a higher mean was obtained from males versus females using the D setting (P < 0.039; male mean 12.1 ± 1.9 mm Hg; female mean 10.9 ± 1.2 mm Hg). Measurements obtained from the STT were not affected by either age or sex. Corneal height was 11 mm and width was 12 mm, regardless of age or sex. The rebound tonometer D setting is recommended for measuring IOP values in this species. Burrowing owls had inconsistent mydriasis following topical rocuronium bromide application to the eye; however, a complete fundic examination was possible with or without complete mydriasis.

Analysis of pupil size by repeat dilation at shrinkage stage.

PURPOSE: To compare the pupil size of the original mydriasis and repeat mydriasis at the pupil shrinkage stage. METHODS: Randomized prospective study. In total, 60 eyes of 30 patients aged 50-70 with age-related cataracts were included. Pupil sizes were measured by the Sirius system before mydriasis, after the first batch of mydriasis, and after the second batch of mydriasis which was 5 h later. Statistical analysis was performed using MedCalc statistical software version 20.0.3 RESULTS: The pupil size of the second batch of mydriasis 5 h later was smaller than the first batch of mydriasis (3.94 ± 0.88 mm vs 5.12 ± 0.96 mm, P < 0.0001). CONCLUSIONS: Less efficiency repeat mydriasis several hours later compared with original mydriasis in our study suggests that preparation of mydriasis at an appropriate time is necessary for ophthalmological operations. The effect of repeat mydriasis again by tropicamide at the shrinkage stage still needs to be explored.

Iris stromal cell nuclei deform to more elongated shapes during pharmacologically-induced miosis and mydriasis.

Nuclear shape alteration in ocular tissues, which can be used as a metric for overall cell deformation, may also lead to changes in gene expression and protein synthesis that could affect the biomechanics of the tissue extracellular matrix. The biomechanics of iris tissue is of particular interest in the study of primary angle-closure glaucoma. As the first step towards understanding the mutual role of the biomechanics and deformation of the iris on the activity of its constituent stromal cells, we conducted an ex-vivo study in freshly excised porcine eyes. Iris deformation was achieved by activating the constituent smooth muscles of the iris. Pupillary responses were initiated by inducing miosis and mydriasis, and the irides were placed in a fixative, bisected, and sliced into thin sections in a nasal and temporal horizontal orientation. The tissue sections were stained with DAPI for nucleus, and z-stacks were acquired using confocal microscopy. Images were analyzed to determine the nuclear aspect ratio (NAR) using both three-dimensional (3D) reconstructions of the nuclear surfaces as well as projections of the same 3D reconstruction into flat two-dimensional (2D) shapes. We observed that regardless of the calculation method (i.e., one that employed 3D surface reconstructions versus one that employed 2D projected images) the NAR increased in both the miosis group and the mydriasis group. Three-dimensional quantifications showed that NAR increased from 2.52 ± 0.96 in control group to 2.80 ± 0.81 and 2.74 ± 0.94 in the mydriasis and miosis groups, respectively. Notwithstanding the relative convenience in calculating the NAR using the 2D projected images, the 3D reconstructions were found to generate more physiologically realistic values and, thus, can be used in the development of future computational models to study primary angle-closure glaucoma. Since the iris undergoes large deformations in response to ambient light, this study suggests that the iris stromal cells are subjected to a biomechanically active micro-environment during their in-vivo physiological function.

A new medication, a new toxidrome - A case report of anticholinergic wipe toxicity due to improper medication use.

We describe a case of a young female who presented to the emergency department with 4 days of progressive myopia, dry mouth, anhidrosis and urinary hesitancy due to overuse of a new topical anticholinergic wipes, glycopyrronium tosylate (GT). In the United States medication misuse accounts for nearly 10% of pediatric emergency visits with 65% of these visits considered to be preventable [1]. Being familiar with new medications and their side effect profiles can prevent unnecessary or harmful interventions.