Case Study: Infectious Mononucleosis, A Rare Cause of Transient Mydriasis

Anisocaria is a condition characterized by unequal pupil size. The potential causes of anisocaria range from benign to potentially life threatening processes. Therefore, determining the etiology is of great importance. Mydriasis, more specifically, is when anisocaria is caused by an abnormally dilated pupil. There are several well-known causes of this phenomenon, however the objective of this clinical case study is to present an unusual cause of mydriasis to help provide more insight into a potentially challenging diagnosis. A 14-year-old female presented to the ED with chief complaints of sore throat, fatigue, and a dilated left pupil. She reported headache at the time of symptom onset, however that resolved prior to presentation. She wears contact lenses, changing them daily, and denied any changes to her regimen or exposure to any chemicals. She denied any traumatic injury, visual changes, and only noticed that her pupils were different in size because somebody else informed her. On exam, patient’s pupils unequal, with left pupil approximately 4mm larger than right. Both pupils were round, and reactive to light. Fundus exam was normal. No other focal neurological deficits were noted. Other physical exam findings where positive for anterior cervical lymphadenopathy, and posterior oropharyngeal erythema. Testing in ED was significant for positive infectious mononucleosis antibody screen. Patient had no other findings concerning for malignant underlying process, so she was discharged home with symptomatic treatment of mono, instructions to remove contact lens, and to follow up ophthalmology. After discharge, patient was evaluated by ophthalmologist, and subsequently referred to neuro-ophthalmologist due to unexplained persistent mydriasis. Prior to neuro-ophthalmology evaluation, her symptoms resolved, 8 days after initial onset. After further workup by neuro-ophthalmologist, it was determined that her transient mydriasis was related to autonomic nervous system irritability secondary to regional inflammation from infectious mononucleosis pharyngitis. Anisocaria results from one pupil having either impaired constriction or dilation. The parasympathetic and sympathetic pathways mediate these processes. To determine which pathway is involved, examination in light/dark conditions, and evaluating pupillary response to light and near stimuli is used. In mydriasis, the anisocaria is greater in light conditions, signifying an abnormal ability to constrict, or in other words, an interruption in normal parasympathetic function. Common causes of mydriasis include trauma, oculomotor nerve palsy, tonic pupil (damaged to ciliary ganglion or short ciliary nerves), or pharmacologic causes with drugs such as atropine, phenylephrine, clonidine, apraclonidine, cyclopentolate, scopolamine patches, aerosolized ipratropium, and jimsonweed. Infection is not typically considered one of the common causes of this condition, but as seen in the case presented, do not forget to include it in your differential, as this knowledge may aid in early diagnosis and help to prevent unnecessary testing and further workup.https://scholarlycommons.henryford.com/merf2020caserpt/1030/thumbnail.jp

Intra-articular dexmedetomidine and clonidine for postoperative analgesia in arthroscopic knee surgery

Background: Many drugs have been used for postoperative pain management which is a common and distressing symptom after knee arthroscopy. But no single ideal intra-articular drug has been found. This study was done to assess the efficacy of intra-articular dexmedetomidine and clonidine for postoperative pain relief in patients undergoing arthroscopic knee surgeries.Methods: Fifty  patients of American Society of Anaesthesiologists of  grade I/II, aged 20-70 years posted for arthroscopic knee surgery were randomly divided into groups I (clonidine group) and group II (dexmedetomidine group). 25 patients in group I received  1 µg/ kg of clonidine diluted to 20 ml in normal saline and group II patients received 1 µg/kg of dexmedetomidine diluted to 20 ml in normal saline via intra-articular route at the end of the surgery. Visual analogue score (VAS), time to give the first dose of analgesia and total dose of analgesic required in first 24 hours was evaluated in each group.Results: VAS score was lower and time to first analgesic requirement was greater in Group II in comparison to Group I which was statistically significant. Total dose of analgesic used in Group II patients was significantly less compared to patients in Group I which was statistically significant. Conclusions: Intra-articular dexmedetomidine is more effective in providing prolonged postoperative analgesia after arthroscopic knee procedures and reduces the total dose of analgesic required postoperatively compared to clonidine.

Efficacy of apraclonidine eye drops in treating ptosis secondary to myasthenia gravis: A pilot clinical trial

Introduction/Aims: Most patients with myasthenia gravis (MG) develop ocular manifestations during their illness and up to 22% may have isolated ocular myasthenia gravis (OMG). Apraclonidine elevates the eyelid by activating alpha-2 receptors on Muller's muscle, an accessory eyelid elevator muscle. In this study we evaluate the effect of apraclonidine in alleviating ptosis secondary to MG. Methods: This clinical trial (NCT05045248) was done at the American University of Beirut Medical Center. Patients with ptosis secondary to MG were administered two drops of apraclonidine 0.5% solution to the most affected eye. We measured palpebral fissure height (PF), marginal reflex distance-1 (MRD1), marginal reflex distance-2 (MRD2), and levator function (LF) before drug administration and at 1, 5, 30, and 60 minutes after administration. Results: Ten participants were enrolled in the study. Improvement in all eyelid measurements was noted in all participants as early as 1 minute after apraclonidine administration. From baseline to 60 minutes after administration, average PF increased from 8.8 ± 1.9 mm to 14.2 ± 2.6 mm, MRD-1 from 1.7 ± 1.4 mm to 5.4 ± 2.9 mm, MRD-2 from 7.1 ± 1.3 mm to 8.8 ± 1.7 mm, and LF from 13.4 ± 2.9 mm to 17.5 ± 2.4 mm. All increases were statistically significant. Discussion: Apraclonidine may alleviate ptosis secondary to MG and may be an effective alternative treatment for this group of patients. © 2023 Wiley Periodicals LLC

Cellular Mechanisms of Ocular Hypotensive Effects of a₂-Adrenergic Agonists

Th ocular bilateral hypotensive effect after unilateral topical administration of medetomidine and 4 analogs was demonstrated in a dose-response study (0.5%-2%) in NZW rabbits (bilateral IOP-lowering efficacy: medetomidine>detomidine and MPV-1440>MPV-1441 and MPV-305BIII)

Nanochanneled Device and Related Methods

A nanochannel delivery device and method of manufacturing and use. The nanochannel delivery device comprises an inlet, an outlet, and a nanochannel. The nanochannel may be oriented parallel to the primary plane of the nanochannel delivery device. The inlet and outlet may be in direct fluid communication with the nanochannel

The bovine perfused eye as a model for pharmacological investigations

The isolated perfused eye of many species has become a frequently used model in the study of ocular pharmacology. Due to its availability, cheapness and comfortable size for experimental use the bovine eye provides an attractive model for conducting perfusion experiments. Although initially rejected by Kishida et al. (1985), the bovine perfused eye has been proved to be a valid model for studying aqueous humour dynamics and the pharmacology of various antiglaucoma drugs, including the β-adrenoceptor antagonist, timolol, and the carbonic anhydrase inhibitor, MK-927 (Wilson et al., 1993). A general aim of this study was to develop the in vitro bovine perfused eye, to show whether it is a useful model for experimental work in studying drug mechanisms in the eye, whether from a pharmacodynamic or pharmacokinetic point of view. Pharmacodynamic Study The procedure for dissection and setting up of the constant flow method for the bovine perfused eye was initially described by Wilson and co-workers (1993). Bovine eyes, obtained from the local abattoir, were cannulated via the long posterior ciliary artery and perfused with Krebs' solution. In order to monitor drug effects on intraocular pressure the anterior chamber was cannulated and connected to a water manometer. Since some drugs affect vascular resistance, the arterial perfusion pressure was continuously measured. Drug solutions or vehicles were administered by one of three routes; (i) by addition of drug to the perfusate reservoir at an exact concentration, (ii) as a bolus dose injected intra-arterially or (iii) as a bolus dose injected intracamerally. Constriction of the pupil, in response to pilocarpine (10 -6M), shown by a significant decrease in pupil diameter, indicated that following intra-arterial administration, drugs have access to the anterior segment of the eye, including the iris sphincter and therefore very probably the ciliary muscle, since their arterial supply is common. To investigate the bovine perfused eye as a model for studying intraocular pressure and aqueous humour dynamics, we studied four different drugs known to alter either aqueous humour formation or aqueous humour outflow. The results show that experimentally damaging the cornea, effectively removing the barrier properties of the corneal epithelium, increases the amount of aciclovir absorption in the cornea and aqueous humour compared with the undamaged cornea. The observed increases in absorption of aciclovir following experimental damage are much greater when the drug formulations have hydrophilic properties, such as the PVA film and aqueous gel. From the present work, the formulations can be ranked in order of corneal and aqueous humour absorption of aciclovir: Ointment < PVA Film < Aqueous Gel In this model the level of drug penetration in the cornea and aqueous humour can be measured without the complications associated with in vivo studies. Due to the lack of in vivo factors such as blinking, drug dilution, drainage and conjunctival absorption the levels of absorption found in the present model are likely to be exaggerated. Nevertheless, the bovine perfused eye provides a useful model for pharmacokinetic studies, which is perhaps superior to the isolated corneal preparation nominally used to assess corneal drug absorption since conditions are more physiological and no edge-damage has been inflicted on the cornea