Davin Johnson's research while affiliated with Queen's University and other places

Publications (39)

Article
Objective To evaluate the long-term evolution of first-line glaucoma therapy (FLGT) initiated by ophthalmologists and optometrists. Design Retrospective population-based study using validated provincial health care databases. Participants 194,759 Ontario residents, 66 years of age or older, who received FLGT between 2007 and 2018. Methods A tota...
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Full-text available
Purpose: To evaluate evolution in the distribution of new glaucoma patients between ophthalmologists and optometrists, and to examine factors predicting provider type, in the context of expansion in the scope of optometry practice. Patients and methods: A population-based study was undertaken using validated datasets in Ontario, Canada from 2007...
Article
Purpose To investigate patient-level factors associated with first-line glaucoma therapy with laser trabeculoplasty (LT) versus topical medication. Design Population-based study. Participants All patients 66 years of age and older in Ontario, Canada, receiving first-ever therapy for glaucoma with either LT or topical medication between April 1, 2...
Article
Objective: To report on patterns of optometry prescribing and adherence to prescribing regulations at a tertiary care ophthalmology centre. Design: Prospective cohort study. Participants: All new referrals from optometrists and other health care professionals to the emergency eye care service (n = 1965) between July 2011 and June 2012, as well...
Article
To quantify the association between subjective visual reduction (SVR) and retinal pathology in patients with acute-onset monocular floaters or flashes, or both. Prospective cohorts study involving all new patients referred for acute-onset floaters or flashes, or both, to a tertiary care emergency eye clinic in Kingston, Ontario, between July 1, 201...
Article
To report the efficacy of intravenous mannitol in the treatment of orbital compartment syndrome. An experimental study was conducted on 4 nonhuman primates (8 orbits). Orbital compartment syndrome was simulated by injecting autologous blood into both orbits of each nonhuman primate until a pressure of 80 mm Hg was reached (time 0). After 10 minutes...
Article
To determine features of eyelid lesions most predictive of malignancy, and to design a key to assist general practitioners in the triaging of such lesions. Prospective observational study. Department of Ophthalmology at Queen’s University in Kingston, Ont. A total of 199 consecutive periocular lesions requiring biopsy or excision were included. Fir...
Article
Introduction: Orbital compartment syndrome may rarely occur in the setting of burns where therapy includes aggressive fluid resuscitation. Case: We report a case of bilateral orbital compartment syndrome in a 13-year-old male, with superficial facial burns secondary to hydrobromic acid, who did not receive aggressive fluid resuscitation. The pat...
Article
To report the causative factors and surgical candidacy of patients referred to an oculoplastic surgery clinic for the complaint of epiphora. Prospective observational study. Consecutive patients (n = 159) referred to a tertiary care oculoplastic surgery clinic over a 12-month period for the complaint of epiphora. The causative factor most responsib...
Article
In Reply The criterion standard for measurement of intraocular pressure is GAT. Dr Huang and colleagues state that general physicians should be cautious when using a commonly accepted threshold intraocular pressure of 22 mm Hg if measurements were not performed using GAT. All studies in our meta-analysis used GAT under rigorous conditions. The resu...
Article
Glaucoma is the second leading cause of blindness worldwide, and its insidious onset is often associated with diagnostic delay. Since glaucoma progression can often be effectively diminished when treated, identifying individuals at risk for glaucoma could potentially lead to earlier detection and prevent associated vision loss. To quantify the diag...
Article
Introduction: Merkel cell carcinoma is an aggressive malignancy often associated with metastatic spread, but has never been reported to metastasize to the orbit. Case: An 80 year old male with metastatic Merkel cell carcinoma presented with ptosis and extraocular movement abnormalities, and was found to have a lesion of the orbit consistent with...
Article
Purpose of review: This study reviews differences in both ocular and systemic safety between intravitreal bevacizumab and ranibizumab in the setting of neovascular age-related macular degeneration. Recent findings: Serious adverse events associated with either bevacizumab or ranibizumab injections are generally rare. However, acute intraocular i...
Article
To compare the rate of serious ocular and systemic adverse effects of intravitreal bevacizumab and ranibizumab in the treatment of a variety of eye diseases. Retrospective chart review. Consecutive series of intravitreal injections of bevacizumab (n = 693) and ranibizumab (n = 891). Medical records of all patients receiving injections in the series...
Article
To evaluate the efficacy of a combination anaesthetic plus dilating gel (ADG) on pupil dilation (PD) and corneal anaesthesia (KA) compared to traditional preoperative pharmacotherapy for cataract surgery. Prospective, noninferiority study. We studied 20 consenting adults who experienced unilateral cataracts and underwent routine cataract surgery, r...
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Full-text available
A 34-year-old man presented with a 3-year history of itchy skin eruptions on the bilateral axillary fossae. Physical examination revealed well-demarcated, thin, bright red plaques, with a few discrete overlying scales. His medical history was unremarkable, and he denied taking any medications.
Article
Full-text available
A 37-year-old woman presented with a 5-month history of asymptomatic, progressively increasing skin lesions on the right side of her face. Skin examination revealed red to violaceous indurated papules and plaques over the right cheek. No other abnormality was present on physical examination. The patient was otherwise healthy, was not taking any med...
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To determine the incidence and characteristics of acute intraocular inflammation after intravitreal bevacizumab injections from a tertiary care retinal practice. Retrospective cohort study. A consecutive series of patients who had received bevacizumab injections performed by a single surgeon. We reviewed the records of all patients with severe ante...
Article
In Reply: In response to Dr Katzeff, we believe that a minimum evaluation for a patient presenting with presumed acute posterior vitreous detachment (PVD) should include focused history, visual acuity measurement, and confrontational visual fields. This evaluation is time-efficient (no more than 10 minutes in total) and should be feasible for busy...
Article
To compare health-related quality of life (HRQoL) in American vs. Canadian populations suffering from retinal diseases. A search of Medline was conducted according to a strategy that combined the MeSH heading 'retinal diseases' with either of 'quality of life' as a MeSH or 'utility' as a keyword. We included studies of American or Canadian patients...
Article
Full-text available
Acute onset of monocular floaters and/or flashes represents a common presentation to primary care physicians, and the most likely diagnosis is posterior vitreous detachment (PVD). A significant proportion of patients with acute PVD develop an associated retinal tear that can lead to retinal detachment and permanent vision loss if left untreated. To...
Article
To compare retinal nerve fibre layer (RNFL) thickness measurements acquired using spectral domain (SD) and time domain (TD) optical coherence tomography (OCT) systems. Prospective clinical study. Twenty eyes of 20 healthy volunteers. All patients underwent 3 sets of circular OCT scans around the optic disc using both a TD OCT system, and a new SD O...
Article
To evaluate the efficacy of prophylactic administration of the topical nonsteroidal antiinflammatory drug (NSAID) ketorolac tromethamine 0.5% on acute (within 4 weeks of surgery) cystoid macular edema (CME) and total macular volume (TMV) in patients having phacoemulsification cataract surgery. Department of Ophthalmology, Queen's University, Hotel...

Citations

... Other items on the differential include culturenegative infectious keratitis, leukemia [44][45][46], indolent systemic infections (e.g., bartonella) [47], Vitamin A deficiency [48], inflammatory bowel disease, anti-myelin oligodendrocyte disease [49,50], sarcoidosis [51][52][53], and autoimmune hepatitis [40]. Recent case reports have focused on new descriptions of medication-associated PUK, such as rituximab [54], tocilizumab [55], dupilumab [56], COVID vaccine [57], checkpoint inhibitors [58,59], and miltefosine [60]. ...
... We used several validated populationbased databases for our study, as previously described. 6,7 Databases were accessed through the secure, privacy-protected environment at ICES (formerly the Institute for Clinical Evaluative Sciences), an independent nonprofit research institute whose legal status allows it to collect and analyze health care data for health system evaluation. These datasets were linked using unique encoded identifiers. ...
... Systemic features can also be present in the acquired Brown syndrome of inflammatory etiology, i.e., superonasal orbital pain and tenderness on movement or palpation. [17] [18] [19] An audible "click" on the ocular movement can be heard. [20] The history and certain physical findings are dependent on the etiology of Brown syndrome and will determine the evaluation and management strategies. ...
Reference: Brown Syndrome
... Delay in diagnosis can result in optic nerve damage due to compression and ischemia. 23,24 Untreated or unrecognized cases may result in permanent visual loss within 90-120 minutes. 25 Therefore immediate management and most importantly recoding of visual acuity at trauma room with proper referral to ophthalmologist and long follow-up is recommended to save vision. ...
... The increase in the fuel price, energy crisis, environmental issues and traffic jams, and the decrease in life quality, as well as in civilians' health, have given rise to the proposition of using public transport systems as well as other non-motor ways. Enhancing physical activity in communities is not achievable only through recommendations and needs especial programmes and infrastructures (Johnson et al. 2016). Since motorised transport is a contributor to sedentary life, a good strategy to increase physical activity would be to bring non-motorised transport to the routine daily lives of people (Wareham et al. 2005;De Geus et al. 2007;Dill, Voros 2007). ...
... It is extremely common for patients to present with monocular floaters and flashing lights to primary care physicians, opticians and eye casualty. The majority of patients are diagnosed with uncomplicated posterior vitreous detachment (PVD) [1]. Indeed, the prevalence of PVD is 87% in those over the age of 80 [2]. ...
... The reviewed papers and main data are shown in Table S1. Four articles reported studies using animals (New Zealand white rabbits, goats, Macaca fascicularis monkeys, and Yorkshire piglets) [13][14][15]21] and seven studies used human cadaver heads for experiments [11,17,18,20,24,26,28]. Only nine articles reported direct OCP measurements in living humans [8][9][10]12,16,19,22,23,27]. ...
... In primary care centers, differentiating a malignant eyelid tumor from a benign tumor can be challenging for the examining physician due to the relatively small size, variability in clinical presentation, and minimal ophthalmologic training in the medical school. 4,5 Oculoplastic surgeons also have only 70% accuracy in diagnosing eyelid tumors. 4 Thus, there is a great need of system which helps the experts in early detection of ocular tumors especially malignant ones with the help of data sets eg. ...
... Studies investigating the etiology of epiphora have demonstrated post-sac drainage impairment (10-41%) [1][2][3][4] , re ex tearing (29-52%) [1][2][3][4][5] and 'multifactorial' epiphora (19-29%) [4][5][6][7] to be the most common causes of presentations to their lacrimal clinics. ...
... V literatuře se můžeme setkat také s termínem orbitální kompartmentový syndrom [39]. Ten obecněji popisuje stav, kdy dochází k nebezpečnému zvýšení intraorbitální tlaku -nejen na podkladě retrobulbárního hematomu, ale i jako komplikaci orbitální celulitidy, výrazného emfyzému, či kolekci tekutiny (například při popálení) [40]. ...