Papers by Michael Ashenhurst
PubMed, Oct 1, 1991
We have developed an endoscopic device for use in the lacrimal drainage system. The device employ... more We have developed an endoscopic device for use in the lacrimal drainage system. The device employs a flexible, small-calibre fibreoptic cable that can easily negotiate the canalicular system. The device can be used in conjunction with a video camera and monitor for simultaneous viewing. The endoscope can be used alone for the diagnosis of lacrimal disorders. Possible future applications include laser treatment of lacrimal disorders.
PubMed, Oct 1, 1987
Spontaneous rupture of Descemet's membrane occurred in a 76-year-old woman with a 20-year history... more Spontaneous rupture of Descemet's membrane occurred in a 76-year-old woman with a 20-year history of Terrien's marginal degeneration. This resulted in corneal hydrops characterized by a clear cystic space filled with aqueous humour that formed between the epithelium and Descemet's membrane. This case represents an unusual complication of Terrien's marginal degeneration.
Canadian journal of ophthalmology, Apr 1, 2004
PubMed, Feb 1, 1991
Two imaging modalities, computed tomography (CT) and dacryocystography (DCG), were combined to de... more Two imaging modalities, computed tomography (CT) and dacryocystography (DCG), were combined to demonstrate the relationships between the lacrimal system and the surrounding soft-tissue structures. In selected cases, such as those involving severe facial trauma, midfacial tumours, significant sinus disease, or previous lacrimal, nasal or sinus surgery, this imaging technique may be useful in better evaluating the anatomy of the lacrimal system and planning a surgical approach.
Canadian journal of ophthalmology, Aug 1, 2007
Restrictive strabismus and diplopia are an uncommon complication of conjunctivodacryocystorhinost... more Restrictive strabismus and diplopia are an uncommon complication of conjunctivodacryocystorhinostomy, with insertion of the Lester-Jones tube. A literature review revealed only 4 published reports of this complication with a total of 4 patients affected. We report on a series of 8 patients who presented with restrictive strabismus and diplopia following Jones tube insertion. Time to presentation was variable and was found to occur from several months to as long as 6 years after insertion. Treatment included topical steroid therapy initially. Surgery was done to release adhesions and scarring if topical treatment failed. Mitomycin C was used in 2 patients. Only 4 of the 8 patients had successful resolution of their diplopia with either therapy. Diplopia following Jones tube insertion is an infrequent complication of surgery. Medical or surgical therapy can be help resolve symptoms but is often unsuccessful.
PubMed, Jul 21, 2023
Purpose: There is no known optimal treatment for primary periocular orofacial granulomatosis (PPO... more Purpose: There is no known optimal treatment for primary periocular orofacial granulomatosis (PPOFG), a disorder that results in periocular edema. This case series and systematic review identifies management strategies and their reported improvement. Methods: Systematic review and case series. PubMed and MEDLINE databases were searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines to identify published cases of PPOFG. Cases were included when edema involved the periocular tissues and when a biopsy was interpreted to be PPOFG. Cases were excluded when edema did not involve the periocular tissues or when the edema was secondary to another process. The electronic medical records of the pathology department were studied to identify cases that were in keeping with PPOFG. The clinical charts were examined to confirm the diagnosis and provide a local case series. Results: There are 38 published cases of PPOFG. An additional 9 cases were identified locally. These cases were combined and analyzed. Most PPOFG has eyelid swelling in isolation, without other facial swelling (36/47; 76.6%). It is most commonly a bilateral disease (30/47; 63.8%). Fissured tongue and facial nerve palsy occur, just as they do in other cases of orofacial granulomatosis. Treatment with surgical debulking or intralesional steroids resulted in high rates of symptomatic improvement of eyelid swelling, but recurrences were common. Conclusions: In light of no curative or highly successful treatment currently available, intralesional steroids and/or surgical debulking are therapies in the treatment of eyelid swelling associated with PPOFG that demonstrate reasonable short- and medium-term results. There is no established therapy that can offer disease remission or long-term symptom improvement.
Investigative Ophthalmology & Visual Science, Apr 17, 2010
Canadian journal of ophthalmology, Feb 1, 2023
Journal of Cutaneous Medicine and Surgery, Mar 2, 2021
In the past few decades, minimally-invasive esthetic treatments and the use of injectable Hyaluro... more In the past few decades, minimally-invasive esthetic treatments and the use of injectable Hyaluronic Acid Gels and other filling agents to treat facial esthetics have increased dramatically. Although extremely rare, a filler can cause ocular and orbital ischemia by retrograde flow from the ophthalmic artery when injected in any of the anastomosis of the face. Once filler reaches the central retinal artery, blindness is inevitable, and no treatment is effective. While the risk of blindness happening with any filler injection is rare, the life-altering irreversible consequence of a procedure that was anticipated to be simple and beautifying is a reality that each injector must be prepared for with every injection. The parameters associated with an iatrogenic stroke of the eye are the site of injection, the injection technique, patient characteristics, and the material injected. Understanding the interplay of each of these variables might help us reduce the possibility of blindness during the injection of a soft-tissue cosmetic filler. Here, we explore the causes of Hyaluronic Acid Gels Filler embolic phenomena, review the natural course of the process, and discuss appropriate immediate interventions. We also (1) propose an education plan for injectors and describe how to carry out a focused ophthalmologic examination and procedural activities for a referral to an ophthalmologist, (2) outline steps to prevent emboli during filler injection, and (3) how to manage and support a patient with a sudden loss of vision during or immediately after a Hyaluronic Acid Gels filler treatment.
Canadian journal of ophthalmology, 2007
Facial Plastic Surgery, Aug 1, 2007
Congenital ptosis is due to a dysgenesis of the levator complex with the levator muscle being rep... more Congenital ptosis is due to a dysgenesis of the levator complex with the levator muscle being replaced by fatty and fibrous tissue. This dysfunction of the levator muscle gives rise to the classic triad of findings in congenital ptosis, including ptosis in the primary position, lagophthalmos in downgaze, and a poorly formed eyelid crease. There are traditionally two ways to surgically correct congenital ptosis, levator resection and frontalis suspension (by utilizing a myriad of both autogenous and synthetic materials). Although frontalis suspension is the more utilized surgical option for the correction of congenital ptosis, the complication rate due to the use of synthetic materials is not insignificant. Many surgeons feel that the contour and appearance of the eyelid following levator resection is superior to the frontalis suspension technique. Thus, levator resection for congenital ptosis can be one of the most satisfactory and physiologically normal of the ptosis procedures. Surgery for congenital ptosis can however be unpredictable in outcome. We propose a modified technique for levator resection as well as a newly designed and modified Berke ptosis clamp for levator resection surgery. Postoperative results with the modified technique as well as clamp have been very encouraging with excellent postoperative lid contour and height. The author has utilized this clamp and modified technique in over 350 lid surgeries over the past ten years.
American Journal of Ophthalmology, May 1, 2001
ABSTRACT To report a patient with bilateral lacrimal gland enlargement as the initial manifestati... more ABSTRACT To report a patient with bilateral lacrimal gland enlargement as the initial manifestation of Rosai--Dorfman disease. Case report. A 14-year-old female presented with left lacrimal gland enlargement followed by right lacrimal gland enlargement 11 weeks later. Bilateral lacrimal gland biopsies were performed, and histopathologic examination revealed the diagnosis of Rosai--Dorfman disease. Patients with Rosai--Dorfman disease may present with bilateral lacrimal gland swelling in the absence of lymphadenopathy. Rosai--Dorfman disease should be considered in the differential diagnosis of bilateral lacrimal gland enlargement.
Canadian journal of ophthalmology, Oct 1, 2000
Ophthalmic Plastic and Reconstructive Surgery, Jul 1, 2015
To evaluate a novel combination head-mounted/chest-mounted point-of-view recording system for ocu... more To evaluate a novel combination head-mounted/chest-mounted point-of-view recording system for oculoplastic surgical procedures. The point-of-view head camera captures the surgical field, while the point-of-view chest camera captures a wide field of view to record instrument ergonomics. Various methods of recording were trialed. The head camera with a narrow field of view was better for recording fine details of the surgical field. The chest camera recording a wide field of view was optimal for recording hand positions. Stereoscopic recording of the instrument ergonomics was helpful in relaying the relative positions of the surgeon's hands and instruments. Point-of-view cameras are cost-effective means of recording oculoplastics procedures. The authors feel simultaneously recording the surgeon's ergonomics and the corresponding instrument movements within the surgical field, from the "surgeon's view", will augment surgical education.
SSRN Electronic Journal, 2021
Background: Vaccination against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ... more Background: Vaccination against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first approved on the 8th of December 2020. Though safe and effective, very rare side effects continue to be identified as global vaccination advances. They do not necessarily leave “a signal” in public registries if the incidence remains below previously reported total incidence levels. Optic neuritis (ON) is a rare but recognised adverse event after immunisation. The risk of post-vaccination ON and visual outcome in the context of global vaccination efforts against SARS-CoV-2 are not known. Methods: A global report on 73 deep-phenotyped individuals with post-SARS-CoV-2 vaccination ON observed in 15 of 55 countries with designated experts between 14 February to 18 July 2021. Statistical analyses were performed on type of vaccine, number of jabs, time to onset of ON, demographics, clinical features and treatment. Paraclinical data included immunological testing for autoantibodies ag...
Canadian Journal of Ophthalmology, 2007
We report an incidence of basal cell carcinoma of the lower lid arising in an area of trauma 68 y... more We report an incidence of basal cell carcinoma of the lower lid arising in an area of trauma 68 years after the initial injury. Comments: Because patients may disregard the appearance of a wound in the setting of former trauma, medical practitioners need increased suspicion and surveillance of chronic nonhealing wounds. Observation : Nous faisons état d'un carcinome basocellulaire de la paupière inférieure qui s'est formé dans un secteur traumatisé, 68 ans après la blessure initiale. Commentaires : Comme le patient peut ne pas s'occuper de l'apparence d'une blessure dans le site d'un ancien traumatisme, les médecins doivent davantage faire attention aux blessures chroniques qui ne guérissent pas et les surveiller.
Canadian Journal of Ophthalmology, 2007
Canadian journal of ophthalmology, 2003
Langerhans-cell histiocytosis (LCH) is a disease caused by proliferation of abnormal histiocytic ... more Langerhans-cell histiocytosis (LCH) is a disease caused by proliferation of abnormal histiocytic cells of the Langerhans cell system. It includes the diseases formerly described as histiocytosis X: eosinophilic granuloma of bone, Hand-SchiillerChristian disease and Letterer-Siwe disease. 1 LCH predominantly affects children 1 to 4 years old, although it can affect persons of any age. The estimated incidence is 2 to 5 per million per year in the pediatric population. Lesions can involve a variety of organ systems, including bone, skin, lymph nodes, bone marrow, liver, spleen, lung, gastrointestinal tract, thymus, endocrine glands and the central nervous system (CNS). The morbidity and prognosis of LCH depend primarily on age and the number of organ systems involved. 1 Recently the results of the first randomized international clinical trial of the Histiocyte Society indicated another prognostic factor: patients with systemic LCH who do not respond to therapy within 6 weeks are at increased risk for treatment failure, up to two-thirds dying of this disease.2
Canadian journal of ophthalmology. Journal canadien d'ophtalmologie, 2004
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Papers by Michael Ashenhurst