ORCID Profile
0000-0002-4594-123X
Current Organisations
The University of Auckland
,
Counties Manukau District Health Board
,
Re:Vision
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Publisher: Springer Science and Business Media LLC
Date: 2002
DOI: 10.2165/00002018-200225010-00004
Abstract: Corticosteroids, used prudently, are one of the most potent and effective modalities available in the treatment of ocular inflammation. However, they can produce a plethora of adverse ocular and systemic events. In order to optimise and target drug delivery, whilst minimising systemic adverse effects, a erse range of local ophthalmic preparations and delivery techniques have been developed. Topical drops and ointments remain the primary methods for administration of ocular corticosteroids. However, ocular penetration of topical corticosteroid drops depends upon drug concentration, chemical formulation of corticosteroid, and composition of the vehicle, therefore, apparently small modifications in preparations can produce a more than 20-fold difference in intraocular drug concentration. Periocular injections of corticosteroids continue to have a useful, but limited, therapeutic role and longer acting, intraocular delayed-release devices are in early clinical studies. Although newer corticosteroids with lesser pressure elevating characteristics have been developed, corticosteroid-induced ocular hypertension and glaucoma continue to be significant risks of local and systemic administration. Posterior subcapsular cataract, observed following as little as 4 months topical corticosteroids use, is thought to be due to covalent binding of corticosteroid to lens protein with subsequent oxidation. Inappropriate use of topical corticosteroid in the presence of corneal infections also continues to be a cause of ocular morbidity. Other risks of locally administered ophthalmic corticosteroids include: tear-film instability, epithelial toxicity, crystalline keratopathy, decreased wound strength, orbital fat atrophy, ptosis, limitation of ocular movement, inadvertent intraocular injection, and reduction in endogenous cortisol. This extensive review assesses the therapeutic benefits of locally administered ocular corticosteroids in the context of the risks of adverse effects.
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.3129/I09-003
Abstract: Ophthalmological pharmacology is a rapidly expanding field aimed at achieving the safest and most effective treatment results. Physicians must be aware of the side-effect profiles, both beneficial and harmful, of medications currently used. This review highlights the available data on the effect of some ophthalmic medications on pupil size it was limited to all reports or studies describing topical ophthalmic agents not originally designed or indicated to alter pupil diameter. This awareness will protect patients from unwanted drug-induced side effects and will improve clinical management and patient care.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 05-2021
Publisher: Springer Science and Business Media LLC
Date: 02-06-2021
DOI: 10.1186/S13071-021-04772-9
Abstract: Canine vector-borne diseases (CVBDs) associated to ticks are among the most important health issues affecting dogs. In Italy, Ehrlichia canis , Anaplasma spp., Rickettsia conorii and Borrelia burgdorferi ( s.l. ) have been studied in both healthy canine populations and those clinically ill with suspected CVBDs. However, little information is currently available on the overall prevalence and distribution of these pathogens in the country. The aim of this study was to assess the prevalence and distribution of tick-borne pathogens (TBPs) in clinically suspect dogs from three Italian macro areas during a 15-year period (2006–2020). A large dataset ( n = 21,992) of serological test results for selected TBPs in three macro areas in Italy was analysed using a Chi-square test to evaluate the associations between the categorical factors (i.e. macro area, region, year, sex and age) and a standard logistic regression model (significance set at P = 0.05). Serological data were presented as annual and cumulative prevalence, and distribution maps of cumulative positive cases for TBPs were generated. Of the tested serum s les, 86.9% originated from northern (43.9%) and central (43%) Italy. The majority of the tests was requested for the diagnosis of E. canis (47% n = 10,334), followed by Rickettsia spp. (35.1% n = 7725), B. burgdorferi ( s.l. ) (11.6% n = 2560) and Anaplasma spp. (6.2% n = 1373). The highest serological exposure was recorded for B. burgdorferi ( s.l. ) (83.5%), followed by Rickettsia spp. (64.9%), Anaplasma spp. (39.8%) and E. canis (28.7%). The highest number of cumulative cases of Borrelia burgdorferi ( s.l. ) was recorded in s les from Tuscany, central Italy. Rickettsia spp. was more prevalent in the south and on the islands, particularly in dogs on Sicily older than 6 years, whereas Anaplasma spp. was more prevalent in the north and E. canis more prevalent in the south and on the islands. The results of this study highlight the high seroprevalence and wide distribution of the four TBPs in dogs with clinically suspected CVBDs from the studied regions of Italy. The very high seroprevalence of B. burgdorferi ( s.l. ) exemplifies a limitation of this study, given the use of clinically suspect dogs and the possibility of cross-reactions when using serological tests. The present research provides updated and illustrative information on the seroprevalence and distribution of four key TBPs, and advocates for integrative control strategies for their prevention.
Publisher: MDPI AG
Date: 18-08-2023
DOI: 10.3390/ANTIBIOTICS12081334
Abstract: There have been multiple reports of eye infections caused by antibiotic-resistant bacteria, with increasing evidence of ineffective treatment outcomes from existing therapies. With respect to corneal infections, the most commonly used antibiotics (fluoroquinolones, aminoglycosides, and cephalosporines) are demonstrating reduced efficacy against bacterial keratitis isolates. While traditional methods are losing efficacy, several novel technologies are under investigation, including light-based anti-infective technology with or without chemical substrates, phage therapy, and probiotics. Many of these methods show non-selective antimicrobial activity with potential development as broad-spectrum antimicrobial agents. Multiple preclinical studies and a limited number of clinical case studies have confirmed the efficacy of some of these novel methods. However, given the rapid evolution of corneal infections, their treatment requires rapid institution to limit the impact on vision and prevent complications such as scarring and corneal perforation. Given their rapid effects on microbial viability, light-based technologies seem particularly promising in this regard.
Publisher: Elsevier BV
Date: 09-2007
DOI: 10.1016/J.CLAE.2007.06.005
Abstract: We present a case of a failed penetrating keratoplasty (PKP), comparing the fluorescein staining of the cornea with the conventional technique, and the new technique using the fluorescein filters of a standard fundus camera.
Publisher: Wiley
Date: 14-11-2019
DOI: 10.1111/CEO.13671
Publisher: Elsevier BV
Date: 03-2021
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.JTOS.2022.05.004
Abstract: Preclinical evaluation of the therapeutic potential of antimicrobial 265 nm UVC for infectious keratitis. Four experiments explored UVC: 1) impact on bacterial and fungal lawns on agar, in in idual or mixed culture, 2) bacterial inactivation dose in an in vitro deep corneal infection model, 3) dose validation in an ex vivo porcine keratitis model and 4) efficacy in a masked, randomised, controlled murine keratitis trial using bioluminescent Pseudomonas aeruginosa. Minimum effective UVC exposures ranged between 2 s and 5 s for lawn bacteria and fungi in in idual or mixed culture. Significant P. aeruginosa growth inhibition in the in vitro infection model was achieved with 15 s UVC, that resulted in a >3.5 log UVC inhibited all tested bacteria and fungi, including mixed culture and strains linked to antibiotic resistance, in vitro, with exposures of ≤ 5 s. In vitro and ex vivo testing confirmed therapeutic potential of 15 s UVC. In vivo, 15 s UVC administered in two doses, 4 h apart, proved effective in treating murine bacterial keratitis.
Publisher: Wiley
Date: 03-2008
DOI: 10.1111/J.1442-9071.2008.01703.X
Abstract: The advent of digital photography in the ophthalmic setting has provided not only a means of documenting pathology, but with instantaneous results, it is possible to aid clinical diagnosis and management. This study was designed to demonstrate the ability to image corneal epithelial lesions stained with fluorescein, with a digital fundus camera set on fluorescein angiography settings. The contrast of this technique demonstrated both gross and subtle corneal epithelial lesions better than traditional methods. The results obtained demonstrated the high sensitivity and high contrast images this technique can facilitate in every ophthalmic practice equipped with a fundus camera with digital fluorescein angiography capability.
Publisher: Wiley
Date: 13-11-2018
DOI: 10.1111/CEO.13415
Publisher: BMJ
Date: 29-10-2010
Publisher: Elsevier BV
Date: 02-2022
Publisher: Elsevier BV
Date: 11-2021
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.CLINDERMATOL.2010.11.008
Abstract: Identifying contact allergens in ophthalmic medications can be a challenging and daunting experience. We summarize data on topical ophthalmic medications with the potential to cause periorbital contact dermatitis and allergic conjunctivitis, highlighting current dilemmas and controversies in this area. The following groups of allergens are reviewed: preservatives, antiglaucoma medications (prostaglandin analogues, β-blockers, carbonic anhydrase inhibitors, parasympathomimetics, sympathomimetics), antiinflammatory medications (nonsteroidal antiinflammatory drugs, corticosteroids), antibiotics, antivirals, antiallergic medications (antihistamines, cromones), anaesthetics, mydriatics, and cycloplegics.
Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.CLAE.2022.101702
Abstract: To explore blinking patterns and sagittal eyelid misalignment in the East Asian eye. Forty-four participants (22 females age 26 ± 5 years 52% of East Asian ethnicity) were enrolled in this pilot study and sub ided, based on upper eyelid crease presence and extent, into single (n = 10), partial (n = 11) or double (n = 23) eyelid crease groups. Blinking was filmed surreptitiously with high-speed video simultaneously from an inferior temporal and frontal view. Spontaneous blink rate and type (incomplete, almost complete, or complete) were assessed over a 30 s period. Sagittal misalignment of the lids on closure was graded during complete spontaneous blinks, voluntary lid closure and voluntary maximal lid contraction (squeezing). A 0.15 µL drop of lissamine green was placed on the central lower lid margin and the number and type of blinks required to eliminate the drop informed complete palpebral apposition during blinking. Mean ± SD blink rates averaged 16.9 ± 10.5 blinks/minute. The proportion of incomplete blinks was 83 ± 22% in single, 58 ± 35% in partial and 59 ± 30% in double eyelid crease groups. The sagittal misalignment of the lid margins during blinking was limited to approximately one-third of the lid margin width this was similar for all lid morphologies and blink types. The lissamine green drop was eliminated only by voluntary maximal lid contraction, and was similar in all groups (p = 0.97). Incomplete blinking and sagittal lid misalignment of the central eyelid margin predominate in habitual blinking, irrespective of lid morphology.
Publisher: Wiley
Date: 29-10-2008
Publisher: Springer Science and Business Media LLC
Date: 04-05-2021
DOI: 10.1007/S00436-021-07166-Z
Abstract: Leishmania major and Leishmania tropica cause cutaneous leishmaniasis in humans and dogs in several parts of the world, with a large number of cases recorded in the Middle East. However, when they occur in sympatry, the role of each species of Leishmania in the epidemiology of cutaneous leishmaniasis (CL) is not clear. To assess the frequency and to identify the species of Leishmania that infect humans and stray dogs in Riyadh and Al-Qaseem (Saudi Arabia), 311 stray dogs and 27 human patients who were suspected for Leishmania infection were examined for CL by a nested polymerase chain reaction (nPCR). Seven (25.9%) out of 27 human patients scored positive for Leishmania spp. (i.e., L. major in five patients from Riyadh and L. tropica in two patients from Al-Qaseem). Out of 311 dogs, five (1.6%) were infected by L. tropica . Data herein presented demonstrate the occurrence of L. tropica in dogs and humans in Saudi Arabia, as well as the occurrence of L . major in humans.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2009
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2008
Publisher: Wiley
Date: 05-2007
DOI: 10.1111/J.1442-9071.2007.01487.X
Abstract: The authors present a case of bilateral sequential extraocular muscle haematoma, for which no apparent cause has been identified despite extensive investigation, and which resolved without persisting morbidity. As far as the authors are aware, this is the first bilateral case to be reported.
Publisher: Wiley
Date: 30-06-2021
DOI: 10.1111/CEO.13959
Abstract: Few studies have evaluated corneal crosslinking (CXL) in a prospective, randomised fashion. This study aimed to determine the efficacy and safety of CXL to reduce the progression of keratoconus. Prospective, unmasked, randomised, contralateral eye controlled trial at a tertiary eye centre. Participants : In iduals with bilateral progressive keratoconus. One eye from each subject was randomised to CXL and the contralateral, untreated eye acted as the control. Primary outcome measure : change in maximum keratometry. Secondary outcome measures : uncorrected distance visual acuity, spectacle corrected distance visual acuity, spherical equivalent refraction, simulated keratometry, corneal astigmatism, minimum pachymetry and complications. Thirty‐eight in iduals (mean age 21.1 ± 6.7 years) were enrolled with one eye treated with CXL. At 5 years, there was a mean decrease in maximum keratometry of treated eyes (−1.45 ± 2.25 D) compared to an increase among the controls (1.71 ± 2.46 D p 0.001). There were significant differences between the treated and control groups in the mean change of Steep SimK (−1.07 ± 1.22 vs. 0.96 ± 1.97 D p 0.001), Flat SimK (−0.61 ± 1.34 vs. 0.43 ± 1.12 D p 0.001), corneal astigmatism (−0.45 ± 1.31 vs. 0.63 ± 1.52 D p 0.01) and minimum pachymetry (−32.49 ± 26.32 vs. −13.57 ± 24.11 μm p 0.01). Complications included sterile infiltrates ( n = 2), microbial keratitis ( n = 1), persistent corneal haze/scarring at 5 years ( n = 4) and loss of ≥2 lines of corrected distance visual acuity ( n = 3). CXL is an effective and relatively safe intervention to halt or reduce the progression of keratoconus in the majority of eyes for at least 5 years.
Publisher: BMJ
Date: 04-2005
Publisher: SAGE Publications
Date: 2018
DOI: 10.2500/AJRA.2018.32.4494
Abstract: Epiphora has a significant impact on the patient's quality of life and is commonly caused by nasolacrimal duct obstruction. Dacryocystorhinostomy (DCR) has traditionally been performed via an external approach, which involves a skin incision. With the advent of endoscopes, the endonasal approach to DCR has gained significant popularity. To prospectively compare the quality of life of adult patients who underwent either an endonasal or an external DCR for acquired nasolacrimal duct obstruction, the Lacrimal Symptom Questionnaire (Lac-Q) was administered before and after surgery. The treatment group assignment was nonrandom and performed based on patient preference. The Lac-Q is a validated questionnaire that assesses the subjective perception of one's well-being from an eye-specific symptom and social impact standpoint. Total scores range from 0 (no concerns) to 33 (maximal degree of ocular symptoms and social impact). Sixty patients (22 in the endonasal group, 38 in the external group) were recruited between January 1, 2014, and January 1, 2016. Postoperative assessment was performed at 3 and 6 months. Patients who underwent external DCR reported a median 7.0–point improvement (interquartile range [IQR], 3.0–11.0) in total Lac-Q scores. A 12.0–point improvement (IQR, 10.0–18.5) was seen in the endonasal group (p = 0.005). The median change in the social impact score was 3.0 and 4.0 in the external group and the endoscopic group, respectively (p = 0.029). Changes in the median lacrimal symptom score were 4.0 in the external group and 8.0 in the endoscopic group (p = 0.014). The anatomic patency rate was lower in the external group (60.0%) when compared with the endonasal group (90.4%). Patients in the external DCR group were significantly older (median age, 51 versus 41 years). Our study indicated that both endonasal and external DCR can lead to improvement in quality of life by using a validated questionnaire. Although there are differences in age and anatomic success rates between the two groups, subgroup analyses indicated that the differences in the Lac-Q scores persisted when age and anatomic patency were removed as potential confounding factors. Further larger, randomized studies would be helpful.
Publisher: Elsevier BV
Date: 08-2021
Publisher: Wiley
Date: 03-2011
DOI: 10.1111/J.1442-9071.2010.02471.X
Abstract: A prototype solid-state Ultraviolet-C (UVC) LED device may be useful in the treatment of corneal microbial infections, as UVC is commonly used for eradicating bacteria, fungi and viruses in other settings. This study assessed the efficacy of 265 nm UVC from this LED, on four different bacterial strains, and investigated the consequences of corresponding exposures on human corneal epithelial cells in vitro. Agar plate lawns of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Streptococcus pyogenes were exposed to a 4.5 mm diameter 265 nm UVC beam at a fixed intensity and distance, for 30, 5, 4, 2 and 1 seconds. Growth inhibition was assessed with a BioRad Gel imager, and the diameter of lucent areas of bacterial inhibition recorded. Human corneal epithelial cells cultured on glass cover-slips were exposed to corresponding doses of UVC from the same device. Live/dead staining was performed and the results quantified. There was 100% inhibition of growth for all bacteria tested, at all exposure times. A 30-second exposure of human corneal epithelium to UVC gave no statistically significant decrease (P = 0.877) in the ratio of live to dead cells when compared to control cultures. The results confirmed that a 1 second exposure to germicidal UVC from this LED source was sufficient to inhibit microbial proliferation in the four bacterial strains tested in vitro. The literature suggests UVC at this dose could potentially be beneficial in treating corneal surface infections, without causing significant adverse effects, supported by our findings in human corneal epithelium exposed to UVC.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Wiley
Date: 16-11-2017
DOI: 10.1111/CEO.13086
Publisher: Hindawi Limited
Date: 2016
DOI: 10.1155/2016/3769341
Abstract: Background. The bacteria isolated from severe cases of keratitis and their antibiotic sensitivity are recognised to vary geographically and over time. Objectives. To identify the most commonly isolated bacteria in keratitis cases admitted over a 24-month period to a public hospital in Auckland, New Zealand, and to investigate in vitro sensitivity to antibiotics. Methods. Hospital admissions for culture-proven bacterial keratitis between January 2013 and December 2014 were identified. Laboratory records of 89 culture positive cases were retrospectively reviewed and antibiotic sensitivity patterns compared with previous studies from other NZ centres. Results. From 126 positive cultures, 35 species were identified. Staphylococcus was identified to be the most common isolate (38.2%), followed by Pseudomonas (21.3%). Over the last decade, infection due to Pseudomonas species, in the same setting, has increased ( p ≤ 0.05 ). Aminoglycosides, cefazolin, ceftazidime, erythromycin, tetracycline, and doxycycline were 100% effective against tested isolates in vitro . Amoxicillin (41.6%), cefuroxime (33.3%), and chlor henicol (94.7%) showed reduced efficacy against Gram-negative bacteria, whereas penicillin (51%) and ciprofloxacin (98.8%) showed reduced efficacy against Gram-positive bacteria. Conclusions. Despite a shift in the spectrum of bacterial keratitis isolates, antibiotic sensitivity patterns have generally remained stable and show comparability to results within the last decade from NZ centres.
Publisher: Wiley
Date: 12-2001
DOI: 10.1046/J.1442-9071.2001.D01-16.X
Abstract: Keratoconus is a relatively common, bilateral, non-inflammatory corneal ectasia. The aetiology of this condition is probably multifactorial, or it represents the final common pathway for a variety of different pathological processes. Although a familial history is present only in a minority of cases, one of the major aetiological factors is certainly genetic. This is evidenced by: the condition's familial inheritance its discordance between monozygotic and dizygotic twins and its association with other known genetic disorders such as Down's and Marfan's syndromes. In the keratoconic cornea, a possible genetic predisposition to increased sensitivity to apoptotic mediators by keratocytes has also been hypothesized. Differences in prevalence between ethnic groups have been identified. Recent advances in computerized topographic diagnostic techniques for keratoconus, including forme fruste keratoconus, enables higher accuracy in delineating abnormal from normal, and helps define study populations for genetic linkage studies. However, genetic heterogeneity and the phenotypic ersity of keratoconus means that genetic analysis continues to be a complex process. None the less, it is foreseeable that over the next decade, improved diagnostic techniques, in combination with molecular genetics, may reveal conclusive data on the precise nature of the genetic inheritance of keratoconus in specific populations. This review considers the evidence that suggests keratoconus is primarily an inherited condition, and examines research strategies aimed at unveiling the genetic predisposition, and the enigma of environmental influences on its phenotypic expression.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Wiley
Date: 06-2004
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2009
No related grants have been discovered for Simon Dean.