Medicine & Health

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  • (2020) Ashari Kandy, Divya Jagadeesh
    Thesis
    Aim: To explore the association of optic disc and retinal parameters with myopia, and to determine if models incorporating these parameters can discriminate between myopic versus non-myopic eyes as well as aid in predicting future onset/incidence and increased progression. Methods: Optic nerve head and retinal parameters were systematically analysed using retinal images, spherical equivalent refraction, and axial length data obtained from two pilot studies (n=58 adults; n=56 myopic children, respectively). Thereafter, an association of optic disc and retinal parameters with myopic versus non-myopic eyes were analysed using data from a large population study of Asian children (n= 2995; 6 to 9 years). Multiple logistic regression analysis was performed and receiver operating characteristic (ROC) curves used to determine the ability of optic disc/retinal features to a) differentiate myopes and non-myopes at baseline; b) predict 12-month myopia incidence c) predict 12-month spherical equivalent and axial length change of ≥-1.00D and ≥0.50 mm respectively. The models were validated in a small, independent sample of 380 Asian children aged 5 to 14 years. Results: Optic disc and retinal parameters such as disc rotation, tilt from Vertical, ovality, reduced short axis of the disc, temporal crescent, tessellations, temporal > nasal pRNFL thickness, reduced fovea to disc distance as well a thinner macular thickness were associated with myopia and/or incidence and/or progression. Models incorporating one or more of these parameters had sensitivity/specificity of 77%/83% to discriminate between myopic versus non-myopic eye; 69%/68% to predict the incidence of myopia, and 58%/ 82% and 66%/79% to predict spherical equivalent and axial length change of ≥ 1D and ≥ 0.50 mm respectively. In an independent sample, the sensitivity/specificity of the models to discriminate between myopic versus non-myopic eyes was 90%/79%; to predict the incidence of myopia was 83%/ 50%; whereas models to predict progression had low sensitivity but high specificity. Conclusion: This body of work adds to the knowledge on the optic disc and retinal features associated with myopia and demonstrates that models incorporating such parameters can successfully discriminate between myopic versus non-myopic eyes. These features are also associated with future incidence and/or progression; however, further work is needed to improve the accuracy of models to predict incidence and/or progression.

  • (2020) Arshad, Memoona
    Thesis
    This thesis aimed to assess risk factors for contact lens-related disease with contemporary lens types, investigate associations between water exposure during contact lens wear and storage case contamination, and evaluate the impact of education in the form of a no water sticker on changing water contact behaviour. A prospective case-control study found that poor lens hygiene and water exposure during lens wear were independent risk factors for contact lens-related disease including infiltrative and infectious events (p<0.05). Higher storage case contamination carried 2.12x (95% CI 1.34-3.36) increased risk of contact lens-related disease. To determine associations between water exposure and storage case contamination, a reliable, efficient and cost-effective alternative method for standard plate count was required. The ATP assay was found to be a rapid and scalable storage case quantification technique, based on its lowest detection limit and maximum repeatability, compared with the MTT and Resazurin reduction assays. The LAL assay for endotoxin was used as a surrogate for Gram-negative bacterial contamination of cases. Water exposure during contact lens wear such as showering with lenses was independently associated with increased overall storage case contamination (p<0.001), while swimming with lenses and using wet hands to handle lenses were independently associated with high endotoxin levels, as a surrogate for Gram-negative bacterial contamination (p<0.05). A randomised controlled trial to investigate behaviour changes when a no water sticker was added to the contact lens storage cases found that after 6 weeks, participants assigned to receive the no water sticker had an overall reduced water exposure score and a greater proportion had low endotoxin levels in their storage case, compared to those who did not receive the sticker (p<0.05). However, no significant impact was observed on the individual water contact behaviours and overall storage case contamination. In conclusion, water contact behaviours including showering and swimming while wearing lenses are associated with increased risk of contact lens-related disease and increased storage case contamination. By educating contact lens wearers using the no water stickers, the overall water exposure behaviour was reduced. However, further research on no water stickers to determine the long-term behaviour change and to refine the messaging about avoiding individual water contact behaviours is required.

  • (2020) Bagga, Deepak
    Thesis
    Background: According to the International Classification of Functioning, Disability and Health participation is an outcome of interactions among an individual’s body functions and contextual factors that includes environmental and personal factors. Assessment of contextual factors and participation of children with low vision or blindness can guide the low vision rehabilitation (LVR) service providers to plan their interventions. Purpose: To identify relevant and important content about contextual factors and participation of school-age children (8 - 17 years) with low vision or blindness. Methods: 541 participants consisting of children with low vision or blindness (n=188), parents (n=81), children with normal vision (n=208), teachers (n=52) and LVR service providers (n=12) participated in 58 brainstorming sessions or semi-structured interviews to generate ideas related to contextual factors and participation. Brainstorming sessions were audio-recorded and transcribed. This was followed by identification of relevant concepts and idea synthesis. The Concept Mapping methodology was used to identify contextual factors and participation domains from the perspectives of participants. Rasch analysis assessed the psychometric properties of identified constructs. Results: The synthesis of 2,267 statements provided 120 unique participation statements and 123 contextual factors. Cluster analyses revealed 9 domains of participation: leisure activities, communication, extra-curricular activities, social activities, education, self-care, household chores, general tasks and demands, and mobility; 7 domains of environmental factors: support and attitudes of family members, support and attitudes of teachers, bullying, society, technology, lighting, and services, systems and policies; and 3 domains of personal factors: child’s feelings, confidence and interests. Forty percent of the participation statements and 38% of the contextual factors were rated above average relevance and importance to participation of children with low vision or blindness. Overall participation and contextual factors were multi-dimensional constructs. However, the sub-scales measuring leisure activities, social activities, education, mobility, support and attitude of family members and personal factors possessed acceptable psychometric properties. Conclusions: Results demonstrated that school-age children can identify the relevant and important content and domains of participation and the contextual factors that can influence their participation. The identified multi-dimensional constructs of contextual factors and participation provide a robust foundation for developing the appropriate rehabilitation measures.

  • (2021) Collins, Scott
    Thesis
    Chronic liver diseases including cirrhosis and primary liver cancer are a significant health burden worldwide. Liver cirrhosis is end stage liver injury resulting in a progressive fibrosis phenotype, in which the hepatic architecture is distorted. The most common cause of cirrhosis is chronic liver injury caused by hepatitis B, alcohol related liver disease, hepatitis C or non-alcoholic steatohepatitis. Primary liver cancer is a leading cause of cancer mortality globally and is commonly observed as a progression of liver cirrhosis. Liver injury usually occurs because of immune-mediated or direct injury to the hepatocytes and involves multiple cellular subsets; including hepatic stellate cells, liver adipocytes, liver resident macrophages kupffer cells, endothelial cells and infiltrating immune cells. Injury to these cells result in the release of reactive oxygen species, proinflammatory signals, proliferation-associated cytokines, and the activation of repair pathways. A chronic activation of these signals can result in dysregulation of the normal repair response and generation of a pathogenic fibrotic response. A broadly canonical response, chronic inflammation drives fibrosis and cirrhosis irrespective of liver injury aetiology. The burden of liver disease provides the impetus to pursue the use of representative in vitro models of liver function and responses to injury. Improved 2D and 3D in vitro disease models would enhance our understanding of the causes of liver injury and the development of cirrhosis and primary liver cancer while increasing the efficacy of preclinical drug discovery. Current 2D in vitro assays based on cell lines such as HepG2 that have reduced metabolic capacities compared to primary hepatocytes ex vivo, and the use of primary human hepatocytes suffers from high donor-to-donor variation and only retain in vivo characteristics for a short time ex vivo. The shortcomings of 2D cell culture models have driven the development of 3D cell culture techniques. The advantages of 3D models include replicating the complex attributes of the liver beyond liver specific metabolism, such as increased cell density, organisation, and cell-cell signalling, O2 zonation, as well as the anatomy of the liver lobule and the circulatory system. After a comprehensive review of all the current in vitro models of the liver we hypothesised that a liver organoid cell culture model co-cultured with myofibroblast like hepatic stellate cells can model liver injury. An organoid cell culture is defined as a collection of cells culturing several cell types that develop from stem cells or organ progenitors and self-organise through cell sorting and spatially restricted lineage commitment, similar to organogenesis in vivo. Liver organoids have demonstrated many advantages over conventional in vitro models such as long-term genetic stability, 2D in vivo-like organisation, and maintaining the necessary cellular cross talk and behavioural characteristics of their primary corresponding cells. The focus of this thesis is the application of 3D liver organoids to model and analyse the molecular and cellular effects of liver injury. We established a 3D liver organoid cell culture model from primary mouse tissue and characterised the capacity of these organoids to model liver characteristics in vitro and used this model to define the interactions between organoid hepatocytes and hepatic stellate cells in a co-culture trans-well system. The impact of inflammatory cytokines tumour necrosis factor-α and transformation growth factor-β on this model, as well as other variables such as hypoxia and the anti-fibrosis drug Halofuginone were assessed. Hepatic stellate cell dependent decreases in organoid viability and organoid dependent increases in hepatic stellate cell viability were observed, as well as Halofuginone dependent decreases in hepatic stellate cell viability were also observed. Markers characteristic of liver injury and fibrosis, such as Actn1 and Lamb3 were upregulated in hepatic stellate cells, although collagen expression was downregulated in these cells. Transcriptional profiling revealed a tumour necrosis factor-α mediated apoptotic response in organoids and an inflammatory response in both the organoids and hepatic stellate cells. We concluded that while liver organoids and hepatic stellate cells responded to experimental variables, there were limitations when it came to the cross talk between the cultures in the trans-well system. While apoptotic bodies from the organoids may have stimulated proliferation of hepatic stellate cells, many key genes responsible for liver injury were either not upregulated or were downregulated in co-culture. Electron microscopy analysis of liver organoids showed important ultrastructural changes compared to a whole liver section. Our findings of secreted exosomes, microvilli within the lumen of the organoids, and many ultrastructural features found within liver cells in vivo confirm that our 3D liver organoids closely resemble the liver. We also demonstrated how the use of high-resolution field emission scanning electron microscopy with automated scan resolution can generate a high-resolution ultrastructure map of the whole organoid. This method can also be combined with correlative light electron microscopy for immunofluorescent labelling of proteins of interest using quantum dot nanoparticles. Overall, our 3D organoid model of liver injury had encouraging results and furthering our understanding of pathogenesis of liver fibrogenesis in vitro and the study of novel anti-fibrotic therapeutic agents.

  • (2020) Huang, Jessie
    Thesis
    Purpose: Glaucoma is a leading cause of irreversible vision impairment. As no cure currently exists, preservation of vision and quality of life relies on early detection, timely treatment and long-term monitoring for disease progression. This dissertation aimed to evaluate and develop novel methods for improving current standards of glaucoma management focusing on health care models and clinical measures. Methods: Patients with glaucoma or suspected of having glaucoma were recruited from collaborative care and public hospital eye clinics. The safety and efficacy of collaborative care (between ophthalmologists and optometrists) for glaucoma diagnosis and management in Australia was examined. Utility of instruments for intraocular pressure and visual fields monitoring for identifying progression risk factors were also evaluated. Study designs included observational (cross-sectional and longitudinal) studies and a prospective clinical trial. Data was collected from clinical examination records, through questionnaires, self-monitoring of intraocular pressure with lcare HOME tonometer and standard automated perimetry using the Humphrey Field Analyzer. Results: In Study 1, collaborative refinement of glaucoma suspect referrals resulted in higher positive predictive values and lower false positives compared to standard community optometry care. Study 2 & 3 showed that longitudinal collaborative management of patients resulted in no significant differences in disease progression rates and patient satisfaction compared to ophthalmology-led care. In Study 4 & 5, utility of !care.HOME for measurement of diurnal intraocular pressure was confirmed. Robust estimates were achieved after 7 days of self-monitoring and a clinical framework was developed for interpreting lcare HOME measurements with respect to applanation tonometry. In Study 6, the application of a novel cluster- and statistical separability analysis demonstrated patterns of progression in early glaucoma and potential utility for early detection of glaucoma progression. Conclusions: Contemporary diagnosis and management of glaucoma patients and suspects can be improved through collaborative care between optometrists and ophthalmologists. Integration of intraocular pressure self-monitoring and cluster analysis of visual field results may improve glaucoma management through early detection of risk factors associated with conversion and progression.

  • (2020) Tummanapalli, Shyam Sunder
    Thesis
    Background: Corneal nerve fibers express diffusible, trophic neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) into tears in response to neurogenic inflammation. Impaired corneal nerve fibers have been proposed as early indicators of diabetic peripheral neuropathy (DPN). However, the changes that occur in the concentration of these neuropeptides and their relationship with peripheral neuropathy in the diabetic cohort has not been explored. Aim: To demonstrate the changes the concentrations of substance P and CGRP in tears as a result of corneal denervation in diabetes and their association with severity of DPN. Methods: The concentrations of substance P and CGRP in flush tears were measured by enzyme-linked immunosorbent assay. Corneal nerve fibers were assessed using corneal confocal microscopy. Motor nerve axonal excitability tests were conducted to assess axonal function. Results: Age was identified as a confounding factor and controlled in all subsequent studies. Corneal nerve fiber loss was associated with early markers of axonal dysfunction and severity of neuropathy in type 1 diabetes, suggesting that corneal nerve loss is a generalized neuropathic process. There was a significant reduction in the concentration of substance P in tears in people with type 1 diabetic neuropathy. The concentration of substance P in tears was associated with corneal nerve loss and with the severity of peripheral neuropathy in type 1 diabetes. In type 2 diabetes, there was no difference in neuropeptides between groups, regardless of neuropathic status. In both type 1 and type 2 diabetes, corneal nerve parameters were significantly decreased in DPN. Corneal confocal microscopy had a better diagnostic performance than the nerve excitability measures for detecting DPN in a cohort of participants with type 1 and type 2 diabetes. Tear film substance P concentration had a relatively good diagnostic efficiency in the assessment of DPN and may be used as a potential proxy marker for peripheral neuropathy in type 1 diabetes, but not in type 2 diabetes. The co-existence of renal dysfunction with diabetes does have an added detrimental effect on corneal small nerve fibers. Conclusion: The ocular surface can indeed be a useful means to detect peripheral neuropathic status in diabetes. The measurement of tear film substance P offers significant promise in the detection of DPN.

  • (2021) Tilia, Daniel
    Thesis
    Contact lens (CL) dissatisfaction is the condition in which individuals experience feelings of discontentment specifically associated with wearing CLs. CL-dissatisfaction is associated with discontinuation from lens wear, and the most commonly cited reasons for discontinuation are contact lens discomfort (CLD) and vision-related problems. Binocular vision disorders (BVDs) are disorders of either the accommodative or vergence systems. BVDs have been associated with CLD, but their direct contribution to CL dissatisfaction is unclear. This thesis reports on the contribution of horizontal, non-strabismic BVDs to CL dissatisfaction and the effect of CL designs that alter binocular vision (BV) function on CL dissatisfaction in those with a horizontal, non-strabismic BVD. The OSDI is shown to be a suitable instrument to measure CL-dissatisfaction from CLD and BVDs, while the combined ocular symptoms/environmental triggers subscales and vision subscale of the OSDI are also found to be suitable measures of CLD and BVD symptoms, respectively. Protocols were developed and used for the clinical assessment of CLD and diagnosis of a BVD. A significant proportion of myopic, non-presbyopic adult CL wearers were found to have a BVD, and these wearers experienced the same type of BVDs and at the rate as in a normal population. These CL wearers demonstrated a normal proportion of BVDs and BVD-type. BVDs contributed to CL-dissatisfaction independently of CLD, and the presence of both conditions appeared to be additive for CL dissatisfaction, irrespective of BVD-type. Some BVD symptoms were similar to those experienced with CLD, while those with exo-related vergence disorders and low relaxation-related accommodative disorders experienced symptoms similar to CLD compared to other BVD-types. There was no difference between BVD-types for either CL dissatisfaction or BVD symptoms, and the presence of CLD exacerbated BVD symptoms irrespective of BVD type. A centre-near multifocal and an Extended-Depth-of-Focus (EDOF) design both reduced CL dissatisfaction in those with either an eso-related vergence disorder or low stimulation related accommodative disorder, through the provision of near plus and improved negative fusional vergence. Near phoria with the EDOF CL was dependent on BV-status and tended towards minimal disruption of the accommodative/vergence system. The EDOF design may also reduce CL-dissatisfaction in those with an exo-related vergence disorder or low relaxation related accommodative disorder through this minimal disruption of the accommodative/vergence system and improved positive fusional vergence.

  • (2022) Biswas, Raaj Kishore
    Thesis
    Rear-end crashes are a major part of road injury burden, accounting for one-third of all vehicle-to-vehicle crashes in New South Wales, Australia. Close following or driving with short headways is a key cause, yet the role of driver behaviour in rear-end crash risk is not well researched. The primary aim of this research was to develop a better understanding of rear-end crashes by assessing headways on Australian roads and investigating driver behaviour and performance associated with close following in crash and non-crash scenarios. Two systematic reviews of headway were conducted. First, a review of research on headway identified the need for a consistent and accurate definition of headway, so the thesis puts forward an improved definition. The second review identified the range of external factors that increase the risk of short headway and increase crash risk including speed, task engagement, lead vehicle type, traffic conditions, road characteristics, weather/visibility, drug use, driving fatigue, innovative lane markings, and various warning systems. These factors were then explored in New South Wales data on rear-end casualty and multiple vehicle crashes. The modelling of these associated factors were confirmed as contributing factors in rear-end crashes, congruent with the review of headway. Higher speed, free flowing traffic, volitional task engagement, low cue environments, and collision warning lead to longer headway. Despite lower fatalities, higher odds of injury were observed for rear-end crashes than other crash types. Rear-end crashes were more likely to lead to multiple vehicle crashes, which had a higher chance of fatality than other types of crashes. Finally, naturalistic driving study data was used to investigate headway during normal driving, exploring close following at different speeds and classifying potential risky driving at various headways. In 64 hrs accumulated across 2101 trips, short headways of under 1 s occurred in around 15% of driving. Common manoeuvres to avoid rear-end crashes when close following were changing lanes, or braking, almost always by the following driver. Headway was associated with both driver speed and posted speed limits, decreasing as posted speed limits increased. Over-the-speed-limit driving was observed in all headway scenarios, but especially in higher speed zones. The findings challenge the notion that rear-end crashes are less severe with low injuries. Road users should be made aware of how frequently safe headways are violated and severity of injury outcomes. Driver education, community engagement, application of driver assistance technology consistent with driver behaviour and safety campaigns need to focus on safer speed and headway management to reduce rear-end crash risk.

  • (2022) Chidi-Egboka, Ngozi
    Thesis
    Background: Ocular surface characteristics in children have not been as well investigated as in adults. Children’s digital device usage is rapidly increasing, and smartphones are the most commonly used device. The ocular surface impacts are unknown in children. In adults, use of digital devices induces ocular symptoms, adversely impacts blinking, and disrupts ocular surface homeostasis. Although blinking is integral to a healthy ocular surface, this is yet to be characterised in children, including the effects of digital devices. This thesis aims to characterise the ocular surface of children including blinking and to examine the impact of smartphone use on ocular surface homeostasis in children. Methods: The literature on ocular surface (symptoms, clinical indices, tear film function, blinking) of healthy children was reviewed and a meta-analysis of tear film stability and tear secretion was conducted. Cross-sectional studies of healthy school-aged children were conducted to examine the utility of commonly used adult-validated dry eye symptom questionnaires (SANDE, OSDI, NRS, OCI, DEQ-5, IOSS), and to characterise ocular surface clinical indices. This included blinking which was measured in situ using a novel eye tracking headset (Pupil Labs GmbH, Germany). The impact of one hour smartphone gaming on the ocular surface (including symptoms and blink parameters) of this paediatric population was examined with an intervention study. Blinking was also examined in situ under different conditions and tasks (reading from hard copy and on digital devices, conversation, walking) using the eye tracking headset in healthy adults. Repeatability of blink measurements (blink rate and interblink interval) in adults using the eye tracking headset was determined. Results: Ocular symptoms, tear film function and blinking were sparsely reported in children. The pooled mean by tear stability measurement methods in the meta-analysis were higher than previously reported in healthy adults while the pooled mean for tear secretion by methods were within the expected normal range for adults. Six existing dry eye questionnaires could be successfully used in paediatric eye care, and their repeatability was mostly comparable to that reported previously in adults. More time and assistance were at times required for younger children and specific terms such as ‘gritty’ and ‘foreign body sensation’ were not always well understood by younger children. The DEQ-5 and IOSS are recommended for use in younger age children. Blinking was associated with greater tear volume and worse meibomian gland expressibility but not digital device use, age, sex, or symptoms in children. One hour smartphone gaming led to increased symptoms of dryness, discomfort, and tiredness but did not impact tear film function. Blinking was rapidly reduced by a third within the first minute of gaming and this effect remained unchanged throughout one hour of gaming (p<0.001). Blink rate was consistently slower during all reading tasks compared to conversation (p≤0.002) and walking (p≤0.03), irrespective of task complexity, screen brightness, working distance or device used. Blinking could be reliably measured using a wearable eye tracking headset; the coefficient of repeatability for blink rate was ±12.4 blinks/min. Conclusions: This study established that existing dry eye questionnaires can be reliably used in children to examine the impact of challenges such as digital device use. An eye tracking headset reliably measured blink rate in situ in adults and detected differences in blinking during various real-life tasks. It was successfully used in children to measure blinking in situ showing an immediate and sustained slowing of blinking, evident after up to one hour of smartphone gaming. An hour of smartphone gaming worsened ocular comfort in children but did not appear to disturb the tear film. Given the ubiquitous use of smartphones by children, future work should examine whether effects reported herein persist or get worse over the longer term, potentially causing cumulative damage to the ocular surface. Blink amplitude and relationships with ocular surface clinical indices and digital device use may be explored using the methods established in this study.

  • (2022) Tajbakhsh, Zahra
    Thesis
    Background: The prevalence of ocular allergy is increasing, and dendritic cells (DC) are responsible for the initiation of the allergic response. Although it has been established that DC density increases in vernal keratoconjunctivitis, this is yet to be explored in other more prevalent forms of allergic conjunctivitis. A subclinical state termed “minimal persistent inflammation” has been described in some allergic diseases (e.g., rhinitis, asthma, vernal keratoconjunctivitis) where subjects maintain a base level of subclinical inflammation when not in contact with allergens but display increased susceptibility to developing symptoms in the presence of allergens, this even at subthreshold doses. Minimal persistent inflammation may similarly be a feature of allergic eye disease. Furthermore, most human studies have focused on characterising central corneal DC with little attention to the topographical characteristics of corneal and conjunctival DC or to DC morphology, both of which are important factors to consider in understanding DC activation and migration. This thesis aims to assess corneal and conjunctival epithelial DC (distribution, density, and morphology) in ocular allergy during the active and asymptomatic phases of allergy in humans. Methods: A retrospective study of ocular surface DC density and morphology in participants with systemic allergies, characterised by a positive skin prick test to common allergens compared with those negative to a skin prick test, was undertaken. To enable in vivo confocal microscopy (IVCM) images of DC to be reliably assessed in a clinical setting, a grading system for DC morphology at the ocular surface was developed and validated. Diurnal and topographical changes in DC density and morphology were assessed. Inter and intra-rater repeatability of corneal and conjunctival DC density and morphology was also described. A series of cross-sectional studies in the active and asymptomatic phases of allergic conjunctivitis based in Australia and in the active phase of allergic conjunctivitis and vernal keratoconjunctivitis based in Iran were conducted. Topographical characteristics of corneal and conjunctival DC density and morphology were assessed using IVCM. Results: Longer DC dendrites were observed in systemic allergic participants despite reduced DC density, suggesting an immune response at the ocular surface. A morphology grading system involving cell body size, presence of dendrites, and presence of long and thick dendrites was repeatable and could provide a user-friendly pictorial reference in a clinical setting. Diurnal variation was not observed in ocular surface DC density and morphology, and they could be reliably measured using IVCM. Both allergic conjunctivitis and vernal keratoconjunctivitis were associated with an increase in DC density and changes in morphology, indicating immune activation at the ocular surface. DC with larger cell bodies and a higher proportion of long dendrites at the corneal locations of people with allergic conjunctivitis were suggestive of increased antigen capture capacity of DC. Elevated DC density persisted at all corneal locations in the asymptomatic phase of allergic conjunctivitis but not in the conjunctiva, an indication of persistent inflammation. However, morphology analysis suggested these cells were not activated for antigen capture. In vernal keratoconjunctivitis, compared to non-allergic participants, DC bodies were larger, and more DC with long dendrites were observed at corneal locations. Participants with vernal keratoconjunctivitis had higher DC density at the corneal limbus and larger DC bodies at the corneal centre and periphery compared to those with allergic conjunctivitis. Conclusion: This research established the reliability of assessing ocular surface DC density and morphology using IVCM. Changes observed in DC density and morphology at the ocular surface might serve as biomarkers for the diagnosis and management of active inflammation in ocular allergy. The presence of corneal inflammation during the asymptomatic phase of allergy may have relevance for practitioners aiming to optimise treatment outcomes for their ocular allergy patients. The applicability of the morphology grading system should be explored in different ocular surface inflammatory and immune diseases.