Center for Eye Research Australia
Center for Eye Research Australia
Anderson A.J.,University of Melbourne |
Bedggood P.A.,University of Melbourne |
George Kong Y.X.,Center for Eye Research Australia |
Martin K.R.,University of Cambridge |
Vingrys A.J.,University of Melbourne
Ophthalmology | Year: 2017
Purpose: Recent developments in electronic technology are making it possible to home monitor the sensitivity of the central visual field using portable devices. We used simulations to investigate whether the higher test frequency afforded by home monitoring improves the early detection of rapid visual field loss in glaucoma and how any benefits might be affected by imperfect compliance or increased variability in the home-monitoring test. Design: Computer simulation, with parameter selection confirmed with a cohort study. Participants: A total of 43 patients with treated glaucoma (both open-angle and closed-angle), ocular hypertension or glaucoma suspects (mean age, 71 years; range, 37-89 years), were followed in the cohort study. Methods: We simulated series (n = 100 000) of visual fields for patients with stable glaucoma and patients with progressing glaucoma for 2 in-clinic (yearly and 6-monthly) and 3 home-monitoring (monthly, fortnightly, and weekly) schedules, each running over a 5-year period. Various percentages of home-monitored fields were omitted at random to simulate reduced compliance, and the variability of the home monitored fields also was manipulated. We used previously published variability characteristics for perimetry and confirmed their appropriateness for a home-monitoring device by measuring the device's retest variability at 2 months in a cohort of 43 patients. The criterion for flagging progression in our simulation was a significant slope of the ordinary least squares regression of a simulated patient's mean deviation (MD) data. Main Outcome Measures: The sensitivity for identifying rapid visual field loss (-2 decibels [dB]/year loss of MD). Results: Although a sensitivity of 0.8 for rapid field loss was achieved after 2.5 years of 6-monthly testing in the clinic, weekly home monitoring achieved this by 0.9 years despite moderate test compliance of 63%. The improved performance of weekly home monitoring over 6-monthly clinical testing was retained even when home monitoring was assumed to produce more variable test results or be associated with low patient compliance. Conclusions: Detecting rapid visual field progression may be improved using a home-monitoring strategy, even when compliance is imperfect. The cost-benefit of such an approach is yet to be demonstrated, however. © 2017 American Academy of Ophthalmology.
Du Toit R.,Fred Hollows Foundation New Zealand |
Palagyi A.,Fred Hollows Foundation New Zealand |
Ramke J.,Fred Hollows Foundation New Zealand |
Brian G.,Fred Hollows Foundation New Zealand |
And 2 more authors.
Ophthalmology | Year: 2010
Purpose: To determine the independent, relative, and combined impact of reduced distance and near vision on the vision-specific quality of life (VS QOL) of adults in Timor-Leste. Design: A population-based cross-sectional eye health survey was conducted in urban and rural areas in Timor-Leste. Participants: Participants were 40 years or older. Those with better eye presenting distance vision worse than 6/18, and every third participant with 6/18 or better vision, completed the VS QOL questionnaire: in total 704 of the 1414 participants. Methods: Distance and near visual acuities were measured and eye health was assessed. The VS QOL questionnaire administered by interview was analyzed using Rasch analysis, univariate analysis, and linear regression to determine associations between VS QOL, demographic factors, and levels of visual impairment. Main Outcome Measures: The Timor-Leste VS QOL questionnaire results. Results: Rasch analysis confirmed that for participants both with and without visual impairment, the Timor-Leste VS QOL questionnaire provided a valid and reliable measure, was unidimensional, and had appropriate response categories. There was a consistent pattern of deterioration in VS QOL as vision worsened: for each category of distance- and near-vision impairment, there was an independent and significant change in Timor-Leste VS QOL scores between no visual impairment and either mild, moderate, or severe impairment (P<0.05). Combined distance- and near-vision impairment was associated with a greater impact on VS QOL than categories separately, the impact of severe distance- and near-vision impairment being the greatest and clinically significant: -3.05 (95% confidence interval [CI], -3.60 to -2.49; P<0.05; and 95% CI, <-1.0). Distance vision (37.2%) contributed relatively more than near vision (4.7%) to the total variance in VS QOL (41.9%). Older people, those not married, not literate, and rural dwellers had significantly worse Timor-Leste VS QOL scores (P<0.05). Conclusions: This study provides evidence of independent dose-response relationships between distance- and near-vision impairment and poorer VS QOL. Distance-vision impairment had a relatively larger impact on VS QOL than near-vision impairment. Combined distance- and near-vision impairment was associated with a greater impact on VS QOL compared with the independent impact of distance- or near-vision impairment at similar levels. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2010 American Academy of Ophthalmology.
Wittig-Silva C.,Center for Eye Research Australia |
Wittig-Silva C.,Royal Melbourne Hospital |
Chan E.,Center for Eye Research Australia |
Chan E.,Royal Melbourne Hospital |
And 6 more authors.
Ophthalmology | Year: 2014
Purpose To report the refractive, topographic, and clinical outcomes 3 years after corneal collagen cross-linking (CXL) in eyes with progressive keratoconus. Design Prospective, randomized controlled trial. Participants One hundred eyes with progressive keratoconus were randomized into the CXL treatment or control groups. Methods Cross-linking was performed by instilling riboflavin 0.1% solution containing 20% dextran for 15 minutes before and during the 30 minutes of ultraviolet A irradiation (3 mW/cm2). Follow-up examinations were arranged at 3, 6, 12, 24, and 36 months. Main Outcome Measures The primary outcome measure was the maximum simulated keratometry value (K max). Other outcome measures were uncorrected visual acuity (UCVA; measured in logarithm of the minimum angle of resolution [logMAR] units), best spectacle-corrected visual acuity (BSCVA; measured in logMAR units), sphere and cylinder on subjective refraction, spherical equivalent, minimum simulated keratometry value, corneal thickness at the thinnest point, endothelial cell density, and intraocular pressure. Results The results from 48 control and 46 treated eyes are reported. In control eyes, Kmax increased by a mean of 1.20±0.28 diopters (D), 1.70±0.36 D, and 1.75±0.38 D at 12, 24, and 36 months, respectively (all P < 0.001). In treated eyes, K max flattened by -0.72±0.15 D, -0.96±0.16 D, and -1.03±0.19 D at 12, 24, and 36 months, respectively (all P < 0.001). The mean change in UCVA in the control group was +0.10±0.04 logMAR (P = 0.034) at 36 months. In the treatment group, both UCVA (-0.15±0.06 logMAR; P = 0.009) and BSCVA (-0.09±0.03 logMAR; P = 0.006) improved at 36 months. There was a significant reduction in corneal thickness measured using computerized videokeratography in both groups at 36 months (control group: -17.01±3.63 μm, P < 0.001; treatment group: -19.52±5.06 μm, P < 0.001) that was not observed in the treatment group using the manual pachymeter (treatment group: +5.86±4.30 μm, P = 0.181). The manifest cylinder increased by 1.17±0.49 D (P = 0.020) in the control group at 36 months. There were 2 eyes with minor complications that did not affect the final visual acuity. Conclusions At 36 months, there was a sustained improvement in Kmax, UCVA, and BSCVA after CXL, whereas eyes in the control group demonstrated further progression. © 2014 by the American Academy of Ophthalmology Published by Elsevier Inc.
Frisca F.,University of Melbourne |
Sabbadini R.A.,LPATH |
Sabbadini R.A.,San Diego State University |
Goldshmit Y.,OBrien Institute |
And 4 more authors.
International Review of Cell and Molecular Biology | Year: 2012
Lysophosphatidic acid (LPA) is a bioactive lipid that regulates a broad range of cellular effects in various cell types, leading to a variety of responses in tissues, including in the nervous system. LPA and its receptors are found in the nervous system, with different cellular and temporal profiles. Through its ability to target most cells of the nervous system and its induction of pleiotropic effects, LPA mediates events during neural development and adulthood. In this review, we summarize the current knowledge on the effects of LPA in the nervous system, during development and adulthood, and in various pathologies of the nervous system. We also explore potential LPA intervention strategies for anti-LPA therapeutics. © 2012 Elsevier Inc.
Osthoff M.,Royal Melbourne Hospital |
Brown K.D.,Center for Eye Research Australia |
Kong D.C.M.,Monash University |
Daniell M.,Center for Eye Research Australia |
Eisen D.P.,Royal Melbourne Hospital
Molecular Vision | Year: 2014
Purpose: Pseudomonas aeruginosa (P. aeruginosa) microbial keratitis (MK) is a sight-threatening disease. Previous animal studies have identified an important contribution of the complement system to the clearance of P. aeruginosa infection of the cornea. Mannose-binding lectin (MBL), a pattern recognition receptor of the lectin pathway of complement, has been implicated in the host defense against P. aeruginosa. However, studies addressing the role of the lectin pathway in P. aeruginosa MK are lacking. Hence, we sought to determine the activity of the lectin pathway in human MK caused by P. aeruginosa. Methods: Primary human corneal epithelial cells (HCECs) from cadaveric donors were exposed to two different P. aeruginosa strains. Gene expression of interleukin (IL)-6, IL-8, MBL, and other complement proteins was determined by reverse transcription-polymerase chain reaction (RT-PCR) and MBL synthesis by enzyme-linked immunosorbent assay and intracellular fow cytometry. Results: MBL gene expression was not detected in unchallenged HCECs. Exposure of HCECs to P. aeruginosa resulted in rapid induction of the transcriptional expression of MBL, IL-6, and IL-8. In addition, expression of several complement proteins of the classical and lectin pathways, but not the alternative pathway, were upregulated after 5 h of challenge, including MBL-associated serine protease 1. However, MBL protein secretion was not detectable 18 h after challenge with P. aeruginosa. Conclusions: MK due to P. aeruginosa triggers activation of MBL and the lectin pathway of complement. However, the physiologic relevance of this finding is unclear, as corresponding MBL oligomer production was not observed. © 2014 Molecular Vision.
Phillipou A.,University of Melbourne |
Douglas J.,La Trobe University |
Krieser D.,Sunshine Hospital |
Ayton L.,Center for Eye Research Australia |
Abel L.,University of Melbourne
Developmental Medicine and Child Neurology | Year: 2014
Aim: The aim of this study was to determine whether volitional saccadic impairments are present in children with mild closed head injury (mCHI) and whether these deficits are predictive of ongoing cognitive impairment. Method: We analysed a sample of 26 children with mCHI (20 males, 6 females; mean age 13y 1mo, SD 2y) and 29 age-matched comparison children (20 males, 9 females; mean age 12y 2mo, SD 2y). Participants completed a battery of saccadic eye movement tasks and a set of computer-based cognitive tasks at three time points: within 2 weeks of mCHI, and at 3 months and 6 months. Results: The group with mCHI made fewer errors on the antisaccade task at the first time point and showed increased latencies on prosaccades, correct antisaccades, and corrected antisaccade errors at the third time point (6mo). The group with mCHI also showed poorer performance on the cognitive tasks assessing memory. Interpretation: Even very mild, uncomplicated mCHI in children may persistently affect aspects of executive control and visual processing. © 2013 Mac Keith Press.
Chan E.,Royal Melbourne Hospital |
Snibson G.R.,Center for Eye Research Australia
Clinical and Experimental Optometry | Year: 2013
Over the past decade, corneal collagen cross-linking has become commonplace as a treatment option for individuals with progressive keratoconus. This is based on laboratory data suggesting that cross-linking using riboflavin and ultraviolet-A irradiation increases collagen diameter and the biomechanical strength of the treated cornea. Case series and limited randomised controlled trials support these findings with data demonstrating that cross-linking slows and possibly halts the progression of keratoconus. In some patients cross-linking results in an improvement in maximum corneal curvature, visual acuity, spherical equivalent and higher-order aberrations. The number of reported complications is small. More recently, variations in the treatment protocol have been described, although they have not yet been subject to comparative studies. While the published data indicate cross-linking is effective in modifying the natural history of keratoconus, the long-term impact of this treatment is still unknown. This paper reviews the theoretical basis, pre-clinical research and clinical results of corneal collagen cross-linking in keratoconus. © 2013 Optometrists Association Australia.
Sandhu S.S.,Sunderland Eye Infirmary |
Sandhu S.S.,Center for Eye Research Australia |
Manvikar S.,Sunderland Eye Infirmary |
Steel D.H.W.,Sunderland Eye Infirmary
Clinical Ophthalmology | Year: 2010
Background/aims: To evaluate retrospectively the clinical outcomes of patients presenting with submacular hemorrhage (SMH) secondary to neovascular age-related macular degeneration (nAMD), treated by vitrectomy, submacular tissue plasminogen activator (tPA) injection and pneumatic displacement of SMH with air followed by postoperative intravitreal ranibizumab (RZB). Methods: Patients with SMH and nAMD had 25-guage vitrectomy and subretinal tPA (12.5 micrograms/0.1 mL) with fluid/air exchange. Intravitreal RZB was administered postoperatively to patients eligible for National Health Service (NHS) funded treatment. Results: Of the total of 16 patients, 11 (68.7%) had complete displacement of SMH. The remaining five had residual SMH, mainly subretinal pigment epithelium in location. Three of the four patients who previously had a failed expansile gas pneumatic displacement were successfully displaced with vitrectomy surgery. At presentation 5/16 (31.3%) patients were eligible for NHS funded intravitreal RZB. This increased to 12 patients after the vitrectomy procedure (75.0%). At 6 months postoperatively all improved by ≥1 line. Ten of the 16 patients (63%) improved by ≥2 lines, with 10 of the 12 patients (83%) treated with RZB improving by ≥2 lines. Conclusion: Vitrectomy/subretinal tPA/air to displace SMH followed by intravitreal RZB injection can stabilize/improve vision in patients with nAMD. This technique displaces hemorrhage not displaced by attempted expansile gas techniques. © 2010 Sandhu et al.
Steel D.H.W.,University of Sunderland |
Sandhu S.S.,University of Sunderland |
Sandhu S.S.,Center for Eye Research Australia
British Journal of Ophthalmology | Year: 2011
The exact incidence of submacular haemorrhage (SMH) in patients with neovascular age-related macular degeneration (nAMD) is unknown, and risk factors for its occurrence ill defined. It is known, however, to be a relatively common problem and important because the visual prognosis of these patients is poor. Unfortunately, patients with significant SMH were excluded from all the recent major randomised control trials for nAMD with antivascular endothelial growth factor (VEGF) agents and photodynamic therapy, and as such, the optimum management of patients is uncertain. SMH can present initially or during treatment of nAMD. The location, size, thickness and duration of SMH have an important bearing on treatment and outcomes. Thin or extrafoveal SMH are probably best treated with anti-VEGF agents alone. It has been proposed that patients with moderate-sized SMH, particularly thick haemorrhages, have an improved prognosis with surgical SMH displacement combined with treatment of CNVM if present. SMH drainage, macular translocation and RPE patch grafting are reserved for more severe extensive cases of SMH. Using these techniques, outcomes better than the natural history have been achieved. This review aims to summarise what is known about SMH in nAMD and will discuss a variety of therapeutic interventions.
Center For Eye Research Australia | Date: 2010-08-27
The invention is directed to methods of detecting and/or measuring a feature in a retinal mage. The feature detected and/or measured may be one or more of the optic disc, optic disc centre, optic disc radius, vessel edge, vessel calibre/width and vessel central reflex. One method for detecting the optic disc includes analyzing an image histogram to determine intensity levels; analyzing the intensity levels to determine a threshold intensity for potential optic disc regions; determining the number of pixels for each potential optic disc region; and calculating the centre of each potential optic disc region from the number of pixels in each potential optic disc region to thereby detect the optic disc.