Publications by authors named "Ian McAllister"
Purpose: To compare gene expression changes following branch retinal vein occlusion (BRVO) in the pig with and without bevacizumab (BEV) and triamcinolone acetonide (TA).
Methods: Photothrombotic BRVOs were created in both eyes of four groups of nine pigs (2, 6, 10, and 20 days). In each group, six pigs received intravitreal injections of BEV in one eye and TA in the fellow eye, with three pigs serving as untreated BRVO controls.
Background/objectives: Artificial intelligence can assist with ocular image analysis for screening and diagnosis, but it is not yet capable of autonomous full-spectrum screening. Hypothetically, false-positive results may have unrealized screening potential arising from signals persisting despite training and/or ambiguous signals such as from biomarker overlap or high comorbidity. The study aimed to explore the potential to detect clinically useful incidental ocular biomarkers by screening fundus photographs of hypertensive adults using diabetic deep learning algorithms.
View Article and Find Full Text PDFBackground: Consequences from the COVID-19 pandemic have resulted in the secondary impact of cessation of elective surgical services, amplifying the waiting list problem with devastating patient and surgical training repercussions. With the introduction of the first regional inter-trust daycase elective care centre pilot in Northern Ireland, we aim to assess the impact of this pathway on elective inguinal hernia waiting lists, patient outcomes, and influence on surgical training.
Methods: Data was collected prospectively over a 10-week pilot of consecutive elective day case hernia lists at a newly established regional day surgery centre.
Purpose: To evaluate what clinical gains can be achieved over conventional treatment with ranibizumab alone for central retinal vein occlusion (CRVO) when causal pathology is additionally addressed successfully with a laser-induced chorio-retinal anastomosis (L-CRA).
Design: Two-year extension of prospective, randomized controlled clinical trial.
Methods: A total of 58 patients with macular edema secondary to CRVO were randomized 1:1 to receive either an L-CRA (n = 29) or sham procedure (n = 29) at baseline and then monthly intravitreal ranibizumab 0.
Purpose: Apoptosis is a key process in neural degeneration associated with retinal vascular diseases. Vascular endothelial growth factor (VEGF) antagonists, including bevacizumab, are used to treat macular edema in these diseases. As VEGF has a critical role in the preservation of retinal neuronal cells, this study investigates the effects of bevacizumab on neural damage in a pig model of branch retinal vein occlusion (BRVO) and compares it with triamcinolone acetonide (TA) which is reported to possess neuroprotective properties.
View Article and Find Full Text PDFPurpose: To assess the effect of the total number of fluid-free months after loading on visual and anatomical outcomes in neovascular age-related macular degeneration patients receiving anti-vascular endothelial growth factor therapy.
Methods: This post hoc analysis pooled patient-level data from the brolucizumab 6 mg (n = 718) and aflibercept 2 mg (n = 715) arms of the HAWK and HARRIER randomized clinical trials. Based on data from Weeks 12 to 96, patients were assigned to one of five categories based on fluid-free visits (FFVs; the total number of monthly visits at which they were observed to be without retinal fluid).
Purpose: The purpose of this study was to describe vessel pulse amplitude characteristics in eyes with central retinal vein occlusion (CRVO), hemiretinal vein occlusion (HVO), normal eyes (N1 N1), and the unaffected contralateral eyes of CRVO and HVO eyes (N1 CRVO and N1 HVO), as well as the unaffected hemivessels of HVO eyes (N2 HVO).
Methods: Ophthalmodynamometry estimates of blood column pulse amplitudes with modified photoplethysmography were timed against cardiac cycles. Harmonic analysis was performed on the vessel reflectance within 0.
We have previously reported that porcine retinal veins can be contracted by vasoactive factors such as endothelin-1, but it is still unknown which cells play the major role in such contraction responses. This study seeks to confirm whether retinal vein endothelial cells play a significant role in the endothelin-1 induced contraction of porcine retinal veins. This is a novel study which provides confirmation of the endothelial cells' ability to contract retinal veins using a live vessel preparation.
View Article and Find Full Text PDFPurpose: To analyze the 3-year outcomes in a broad population of patients starting VEGF inhibitors for central retinal vein occlusion (CRVO) in routine clinical practice.
Design: Observational database study.
Participants: Overall, 527 treatment-naïve CRVO eyes that commenced VEGF inhibitors between December 1, 2010 and 2018 were tracked in the Fight Retinal Blindness! registry.
Background: Bevacizumab is the only agent that many people can afford, yet there are only limited data on whether it improves macular oedema (MO) secondary to retinal vein occlusion (RVO) in real-world clinical practice. Here we studied 12-month real-world treatment outcomes of bevacizumab for RVO-related MO.
Methods: This was a multicentre, observational study analysing 12-month data from the Fight Retinal Blindness! (FRB) database.
Purpose: To establish disease progression rates in total lesion size (TLS), decreased autofluorescence (DAF) area, total macular volume (TMV), and mean macular sensitivity (MMS) in PRPH2-associated retinal dystrophy.
Design: Single-center, retrospective chart review.
Participants: Patients with heterozygous pathogenic or likely pathogenic PRPH2 variants.
Background: The COVID-19 pandemic is an evolving healthcare challenge causing secondary disruption of cancer services. Quantitative Faecal Immunochemical Testing (qFIT) has been established as a screening method in asymptomatic patients. We aim to assess its utility as a triage tool to prioritise investigations in symptomatic patients with suspected colorectal cancer.
View Article and Find Full Text PDFObjectives: To identify whether the outcomes of neovascular age-related macular degeneration (nAMD), diabetic macular oedema (DMO) and retinal vein occlusion (RVO) in routine clinical practice have changed over time.
Methods: We analysed 12-month outcomes in treatment-naïve eyes that started aflibercept or ranibizumab for nAMD (3802 eyes), DMO (975 eyes), Branch RVO (BRVO, 357 eyes), Central RVO (CRVO, 371 eyes) and Hemi-RVO (HRVO, 54 eyes) from 2015 and 2019 tracked in the prospectively designed observational Fight Retinal Blindness! Registry.
Results: The mean VA change at 12-month for each year between 2015 and 2019 remained stable or otherwise showed no discernible trends over time in eyes with nAMD (+3.
Purpose: To investigate concordance in symptom onset, area of dark autofluorescence (DAF), and growth rate (GR) between Stargardt disease siblings at an age-matched time point.
Methods: In this retrospective longitudinal study of sibling pairs with identical biallelic ABCA4 variants, age at symptom onset, best-corrected visual acuity, atrophy area, and effective radius of DAF on ultra-widefield fundus autofluorescence were recorded. Absolute intersibling differences for both eyes were compared with absolute interocular differences using the Mann-Whitney test.
Background/aims: To describe baseline characteristics and 12-month outcomes with vascular endothelial growth factor (VEGF) inhibitors of treatment-naïve hemiretinal vein occlusion (HRVO) compared with branch (BRVO) and central (CRVO) variants in routine clinical care.
Methods: A database observational study recruited 79 HRVO eyes, 590 BRVO eyes and 344 CRVO eyes that initiated therapy over 10 years. The primary outcome was mean change in visual acuity (VA-letters read on a logarithm of minimal angle of resolution chart) at 12 months.
Reported growth rates (GR) of atrophic lesions in Stargardt disease (STGD1) vary widely. In the present study, we report the longitudinal natural history of patients with confirmed biallelic mutations from five genotype groups: c.6079C>T, c.
View Article and Find Full Text PDFPurpose: Report the age-standardized annual incidence of blindness registration due to age-related macular degeneration (AMD) in Australia in patients aged 50 years and older. Frequencies of photodynamic therapy (PDT) and intravitreal therapy (IVT) were examined.
Design: Retrospective observational study.
Purpose: To compare 12-month treatment outcomes of eyes receiving aflibercept or ranibizumab for macular oedema secondary to central retinal vein occlusion (CRVO) in routine clinical practice.
Methods: 296 treatment-naïve eyes receiving either aflibercept (171 eyes, 2 mg) or ranibizumab (125 eyes, 0.5 mg) for macular oedema secondary to CRVO were recruited retrospectively from centres using the prospectively designed FRB! registry.
Background: The BEVORDEX trial compared outcomes of eyes with diabetic macular oedema (DMO) randomised to receive either intravitreal dexamethasone (DEX-) implant or bevacizumab over 2 years. We assessed long-term efficacy and safety outcomes 5 years from enrolment.
Methods: Patients received standard clinical care after they finished the study.
Purpose: To establish a mutation-specific age-dependent ultra-widefield fundus autofluorescence (UWF-FAF) trajectory in a large Stargardt disease (STGD1) cohort using total lesion size (TLS) and to develop a clinical method for variant classification.
Methods: A retrospective study of patients with biallelic ABCA4 mutations that were evaluated with UWF-FAF. Boundaries of TLS, defined by stippled hyper/hypoautofluorescence, were outlined manually.
This study examined the frequency of inherited retinal diseases (IRDs) as the reason for blindness registrations over the last two decades and the demographic and clinical phenotypes of inherited retinal disease (IRD)-related registrations. Retrospective, observational study of individuals registered with a state-wide blind and vision-impaired registry. Low-vision or blindness-only (≤20/200 or ≤20°) certificates issued to children (0-15 years), working-age (16-64 years) and older-age (65 and older) adults were assessed.
View Article and Find Full Text PDFObjective: To evaluate the functional benefits (best corrected visual acuity (BCVA), central subfield thickness, injection loads, central venous pressure (CVP)) of a laser-induced chorioretinal anastomosis (L-CRA) in patients with central retinal vein occlusion (CRVO) treated with ranibizumab compared with ranibizumab monotherapy.
Methods And Analysis: This is a post-hoc analysis of the 2-year randomised ranibizumab plus L-CRA for CRVO trial. Twenty-four patients (82.
Background/aims: To compare the efficacy of ranibizumab (0.5 mg) with aflibercept (2 mg) in the treatment of cystoid macular oedema due to branch retinal vein occlusion (BRVO) over 12 months.
Methods: A multicentre, international, database observational study recruited 322 eyes initiating therapy in real-world practice over 5 years.
Purpose: To investigate atrophy expansion rate (ER) using ultra-widefield (UWF) fundus autofluorescence (FAF) in Stargardt disease (STGD1).
Design: Retrospective, longitudinal study.
Participants: Patients with biallelic mutations who were evaluated with UWF FAF and Heidelberg 30° × 30° and 55° × 55° FAF imaging.
Introduction And Aims: Following several deaths due to drug overdoses at music festivals in Australia, pill testing (or drug checking) has been proposed as a means of reducing the risk to young people. However, pill testing is a politically controversial policy in Australia. This paper examines the political dimension to the debate, its relationship with other social issues and how it divides party supporters.
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