Past HDR Students

Sameneh Delshad | Sekar Ulaganathan |Beata Sander | Emily Woodman | Ranjay Chakraborty | Atanu Ghosh | Shila Roshani | Stephen Vincent | Garima Tyagi | David Alonso-Caneiro | Fan Yi | Alyra Shaw | Scott Read | Tobias Buehren | Wilfred Tang | Michael Sydenham | Thomas Tenkate

 


Hosein Hoseini-Yazdi

Thesis Title: Spatial Characteristics of the Response of the Human Posterior Eye to Imposed Defocus

The growth of the eye is influenced by visual experience, specifically the level of blur detected by the retina. Extensive animal studies have shown that choroid plays an important role in the local ocular growth signalling cascade that determines the final status of ocular refraction. Indeed, choroidal thickness alterations form the early phase response of the eye to imposed blur conditions, with choroidal thinning/thickening occurring prior to the development of experimental myopia/hyperopia. Furthermore, these local mechanisms appear to respond differently to visual input in different retinal regions. However, only a limited number of studies have directly investigated the response to alterations in image focus in human eyes and these studies have been limited to small areas of the central retina (≈ 17˚), with the choroidal response to defocus beyond these central retinal regions remaining unexplored.

To improve the understanding of the mechanisms underlying refractive error development, Hosein’s PhD project examines alterations in central and peripheral choroidal thickness following the short-term exposure to myopic and hyperopic retinal image defocus of varying spatial patterns. For this purpose, he studies a wider area of the choroid employing the new technique of enhanced depth imaging wide-field optical coherence tomography (EDI-WFOCT) that provides choroidal thickness data across a 55˚ of the visual field (Figure 1). His early experiments on healthy adults have confirmed the repeatability of wide-field choroidal thickness via EDI-WFOCT imaging. Furthermore, in an attempt to provide a baseline data of central and peripheral choroidal thickness in healthy adults, he has subsequently investigated the wide-field choroidal thickness in a cohort of myopic and emmetropic healthy young adults and has found that the choroid undergoes a substantial peripheral thinning beyond the parafoveal zone and that significant differences in choroidal thickness associated with myopia are largely confined to the central 27˚ macular and near-peripheral zones (Figure 2). Following these baseline findings, he has then undertaken his major interventional experiments to study the influence of various spatial patterns of short-term imposed myopic and hyperopic optical defocus (including full-field, hemi-field and centre/periphery variations in defocus) on wide-field choroidal thickness of young healthy adults and his findings will be soon available.

Publications (arising from thesis):

Information available (shortly)

Conference/Meeting Attendance:

2017 ARVO-ASIA Meeting, Brisbane Convention and Exhibition Centre, 5-8 February, Brisbane, AUSTRALIA.

Conference/Meeting Invitation:

2017 ARVO Annual Meeting, 7-11 May, Baltimore, Maryland, USA.

2016 AAO Annual Meeting, 9-12 November, Anaheim, California, USA.

 

Samaneh Delshad

Thesis Title: Temporal Dynamics of the Eye’s Response to Blur

Emmetropization is the process by which the growing eye matches its length to its optical power, so that the images of distant objects are focused on the retina. Evidence from animal models of eye growth show that ocular growth during the emmetropization process is visually guided. The visual cues that drive the emmetropization process in humans are complex, since the retina does not experience stationary blur, but blur that changes as the eyes change fixation. Thus, the required visual information for eye growth control can only be obtained through continuous temporal averaging of blur. Animal model studies of eye growth suggest a non-linear model of integration of the visual signals. 

To date, it is not clear whether the same non-linearity in the temporal integration of visual signals found in animals also exists in human eyes. This PhD research is aimed to assess the model of temporal integration of defocus blur in human eyes, through a series of experiments examining the short term response of the human eye to blur. Knowledge from this project may ultimately contribute towards a better understanding of methods for myopia control.

In this program of research, a binocular beam splitter periscope system was used to provide constant exposure to defocus and maintain distance fixation during Lenstar biometry. Human eye elongates faster in response to hyperopic defocus than it shortens in response to myopic defocus, during 60 minutes imposed defocus. Following cessation from defocus, the effects of myopic defocus persisted longer than the hyperopic defocus effects, during the recovery.

Publications (arising from thesis):

Information available (shortly)

Conference/Meeting Attendance:

2017 ARVO-ASIA Meeting, Brisbane Convention and Exhibition Centre, 5-8 February, Brisbane, AUSTRALIA.

2017 ARVO Annual Meeting, 7-11 May, Baltimore, Maryland, USA.

2016 AAO Annual Meeting, 9-12 November, Anaheim, California, USA.

Sekar Ulaganathan

Thesis Title: The influence of light and seasonal changes on the daily variation of ocular biometrics and eye growth in young adults

Sekar’s PhD research aims to explore the relationship between ambient light exposure and ocular changes associated with myopia in young adults. Animal studies, and studies in children have shown that ambient light exposure plays an important role in the control of eye growth and in the development of myopia. There is also evidence from animals that daily oscilations in eye biometrics are linked to eye growth and the development of refractive error.  However, there is limited research in young adults examining the role of light exposure, and ocular diurnal rhythms in the regulation of human eye growth, and the interaction between these factors is not well understood. Therefore, this research is utilising objective light exposure measurement techniques, coupled with high resolution ocular imaging to explore the relationship between ambient light exposure, short term diurnal variations and longer term eye growth in young adults.

Publications (arising from thesis):

Information available (shortly)

Conference Proceedings (arising from thesis):

Information available (shortly)

 

Beata Sander

Sander, Beata P. (2017) The influence of the autonomic nervous system on the human choroid. PhD thesis, Queensland University of Technology.

Thesis research concentrated upon defining the role of muscarinic signaling in myopia development. Using a high-speed, high axial resolution, three-dimensional OCT system to acquire chorioretinal images, it has been demonstrated that muscarinic blockers can influence choroidal thickness at least in the short-term, and the blockage of muscarinic signaling can prevent short-term choroidal thinning effect of negative lenses, but doesn’t enhance the effect of positive lenses on choroidal thickness. It has been shown that low-dosage atropine (0.01% atropine) can prevent choroidal thinning in response to negative lenses but its effect is about 50% weaker than 2% homatropine.

Publications (arising from thesis):

Asejczyk-Widlicka, Magdalena, Krzyzanowska-Berkowska, Patrycja, Sander, Beata, & Iskander, D. Robert (2015) Age-related changes in ocular blood velocity in suspects with glaucomatous optic disc appearance. Comparison with healthy subjects and glaucoma patients. PLoS One, 10(7), pp. 1-12.

Sander BP, Collins MJ, Read SA. (2014) The effect of topical adrenergic and anticholinergic agents on the choroidal thickness of young healthy adults. Experimental Eye Research. 30;128:181-9

Read, Scott A., Collins, Michael J., & Sander, Beata (2010) Human optical axial length and defocus. Investigative Ophthalmology and Vision Science, 51(12), pp. 6262-6269.

Conference Proceedings (arising from thesis):

Information available (shortly)

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Emily Woodman

Woodman, Emily Claire (2015) Ocular changes associated with accommodation in myopes and emmetropes. PhD thesis, Queensland University of Technology.

This thesis examines the short-term changes occurring in a number of the eye’s structures during reading tasks, and explores how these changes differ between normal eyes, and those with short-sightedness (myopia). This research revealed changes in the shape and thickness of a number of the eye’s structures during near work, and aspects of these changes showed differences associated with myopia. These findings have potentially important implications for our understanding of the role of near work in the development and progression of myopia.

Publications (arising from thesis):

Woodman, Emily, Read, Scott A., & Collins, Michael J. (2012) Axial length and choroidal thickness changes accompanying prolonged accommodation in myopes and emmetropes. Vision Research: an International Journal for Functional Aspects of Vision72, pp. 34-41.

Woodman-Pieterse, Emily C., Read, Scott A., Collins, Michael J., & Alonso-Caneiro, David (2015) Regional changes in choroidal thickness associated with accommodation. Investigative Ophthalmology and Visual Science56(11), pp. 6414-6422.

Conference Proceedings (arising from thesis):

Woodman, Emily C., Read, Scott A., Collins, Michael J., Davis, Brett A. (2013) A method for measuring retinal and choroidal thickness changes with accommodation.  In 14th International Myopia Conference, 19-22 September 2013, Asilomar, United States of America. (Unpublished)

Woodman EC, Read SA, Collins MJ (2013) Changes in axial length and choroidal thickness during and after prolonged accommodation in myopes and emmetropes. In IHBI Inspires Postgraduate Student Conference, November 2013, Gold Coast, Australia.

Woodman EC, Read SA, Collins MJ (2014) Changes in eye length and choroidal thickness with near work in myopes and emmetropes. In Australian Vision Convention, 2014, Gold Coast, Australia.

Woodman-Pieterse, Emily C., Read, Scott A., Collins, Michael J., & Alonso-Caneiro, David (2015) Response of the anterior sclera to accommodation in myopes and emmetropes. In 15th International Myopia Conference, 23 – 27 September 2015, Wenzhou, China. (Unpublished)

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Ranjay Chakraborty

Chakraborty, Ranjay (2013) Diurnal variation of ocular biometrics under natural and defocused conditions. PhD thesis, Queensland University of Technology.

Awarded: QUT Outstanding Thesis Award for 2013

This thesis examines the diurnal variations in axial length in young normal eyes, the contributing components, and the influence of optical stimuli on these changes.  The results show that axial length undergoes significant diurnal variation in young adult human eyes, and has shown that the natural diurnal variations in choroidal thickness and IOP are significantly associated, and may underlie these diurnal fluctuations in axial length.  This work also demonstrates for the first time that exposing young human eyes to monocular myopic and hyperopic defocus leads to a significant disruption in the normal diurnal rhythms of axial length and choroidal thickness.  These changes in axial length with defocus may reflect underlying mechanisms in the human eye that are involved in the regulation of longer term eye growth.

Publications (arising from thesis):

Chakraborty, Ranjay, Read, Scott A., & Collins, Michael J. (2013) Hyperopic defocus and diurnal changes in human choroid and axial length. Optometry and Vision Science90(11), pp. 1187-1198.

Chakraborty, Ranjay, Read, Scott A., & Collins, Michael J. (2012) Monocular myopic defocus and daily changes in axial length and choroidal thickness of human eyes. Experimental Eye Research103, pp. 47-54.

Chakraborty, Ranjay, Read, Scott A., & Collins, Michael J. (2014) Diurnal variations in ocular aberrations of human eyes. Current Eye Research39(3), pp. 271-281.

Chakraborty, Ranjay, Read, Scott, & Collins, Michael (2011) Diurnal variations in axial length, choroidal thickness, intraocular pressure, and ocular biometrics. Investigative Ophthalmology and Visual Science52(8), pp. 5121-5129.

Conference Proceedings (arising from thesis):

Chakraborty R, Read SA, Collins MJ. Monocular hyperopic defocus and diurnal variations in axial length and choroidal thickness.  Presented at the 14th Scientific Meeting in Optometry and 8th Optometric Educators Meeting, September 2012, Melbourne, Australia.

Chakraborty R, Read SA, Collins MJ. Monocular defocus and diurnal variations in axial length and intraocular pressure of human eyes.  Presented at the Association for Research in Vision and Ophthalmology (ARVO) Conference, May 2012, Florida, United States of America.

Read SA, Chakraborty R, Collins MJ. Changes in diurnal rhythms of choroidal thickness with monocular defocus in human eyes. Presented at the Association for Research in Vision and Ophthalmology (ARVO) Conference, May 2012, Florida, United States of America.

Chakraborty R, Read SA, Collins MJ. Monocular defocus and diurnal variations in axial length of human eyes.  Presented at the IHBI Inspires Conference, November 2011, Brisbane, Australia.

Chakraborty R, Read SA, Collins MJ. Diurnal variations of axial length and IOP over two consecutive days.  Presented at the 13th Scientific Meeting in Optometry and the 7th Optometric Educators Meeting, September 2010, Sydney, Australia. (Published abstract: Chakraborty R, Read SA, Collins MJ. Diurnal variations of axial length and IOP over two consecutive days. Clinical and Experimental Optometry, 2010; 94:e2).

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Atanu Ghosh

Ghosh, Atanu (2012) Optical and biomechanical factors, associated with near work and myopia. PhD thesis, Queensland University of Technology.

This thesis is primarily concerned with investigating the changes in the eye during near work in downward gaze under natural viewing conditions.  The findings of these experiments collectively show the dynamic characteristics of the optics and biometrics of the eye in downward gaze during a near task, over time.  These were small but significant differences between myopic and emmetropic eyes in both the optical and biomechanical changes associated with shifts of gaze direction.  These differences between myopes and emmetropes could arise as a consequence of excessive eye growth associated with myopia.  However, the potentially additive effects of repeated near work activities employing inferonasal gaze could also act to promote elongation of the eye.

Publications (arising from thesis):

Ghosh, Atanu, Collins, Michael, Read, Scott, Davis, Brett, & Iskander, Robert (2011) Measurement of ocular aberrations in downward gaze using a modified clinical aberrometer. Biomedical Optics Express2(3), pp. 452-463.

Ghosh, Atanu, Collins, Michael, Read, Scott, Davis, Brett, & Iskander, Robert (2011) The influence of downward gaze and accommodation on ocular aberrations over time.Journal Of Vision11(10), pp. 1-13.

Ghosh, Atanu, Collins, Michael J., Read, Scott A., & Davis, Brett A. (2012) Axial length changes with shifts of gaze direction in myopes and emmetropes. Investigative Ophthalmology and Visual Science53(10), pp. 6465-6471.

Ghosh, Atanu, Collins, Michael J., Read, Scott A., Davis, Brett A., & Chatterjee, Payel (2014) Axial elongation associated with biomechanical factors during near work.Optometry and Vision Science91(3), pp. 322-329.

Conference Proceedings (arising from thesis):

Ghosh, Atanu, Collins, Michael J., Davis, Brett A., Read, Scott A., Yi, Fan, & Chatterjee, Payel (2013) Changes in ocular biometrics and refraction during near work in downward gaze over time. In Association for Research in Vision and Ophthalmology (ARVO 2013), May 5 – 9, 2013, Seattle, Washington.

Ghosh, Atanu, Collins, Michael J., Read, Scott A., Davis, Brett A., & Chatterjee, Payel (2013) Short-term changes in axial length during simulations of typical far, intermediate and near tasks. In 14th International Myopia Conference, American Academy of Optometry, Stanley Hall UC Berkley and Asilomar, California, United States of America.

Ghosh A, Collins MJ, Read SA, Davis BA, Iskander DR, Chatterjee P. Changes of ocular refraction in downward gaze. Clinical and Experimental Optometry, 2011; 94:e3 (13th Biennial Scientific Meeting, 7th Educators’ Meeting in Optometry 2010, Sydney, Australia).

Ghosh A, Collins MJ, Read SA, Davis BA, Iskander DR, Chatterjee P. A novel technique to assess optical performance of presbyopic corrections in downward gaze. Clinical and Experimental Optometry, 2011; 94:e13 (13th Biennial Scientific Meeting, 7th Educators’ Meeting in Optometry 2010, Sydney, Australia).

Ghosh A, Collins MJ, Read SA, Davis BA, Iskander DR, Chatterjee P. Changes in ocular aberrations during a near task in downward gaze for emmetropes and myopes.  Investigative Ophthalmology and Visual Science, 2011; 52:E-Abstract 6314 (Association for Research in Vision and Ophthalmology, 2011, Fort Lauderdale, United States of America).

Collins MJ, Ghosh A, Read SA, Davis BA, Iskander DR, Chatterjee P. Influence of accommodation and gaze angle on primary and secondary spherical aberration over time. Investigative Ophthalmology and Visual Science, 2011; 52:E-Abstract 829 (Association for Research in Vision and Ophthalmology, 2011, Fort Lauderdale, United States of America).

Ghosh A, Collins MJ, Read SA, Davis BA, Iskander DR. Accommodation and pupil changes over time during a near task. IHBI Inspires Conference, November 24-25, 2011, Brisbane, Australia.

Ghosh A, Collins MJ, Read SA, Davis BA, Chatterjee P. Changes in axial length in the nine cardinal gaze directions over time in emmetropes and myopes. Investigative Ophthalmology and Visual Science, 2012; 53:E-Abstract 4457 (Association for Research in Vision and Ophthalmology, 2012, Fort Lauderdale, United States of America).

Ghosh A, Collins MJ, Read SA, Davis BA, Chatterjee P. Changes in the eye during near tasks in downward gaze. In Southern Regional Congress, 2012, Melbourne, Australia.

Ghosh A, Collins MJ, Read SA, Davis BA. Changes in anterior eye biometrics with shifts in gaze. In 14th Biennial Scientific Meeting, 8th Educators’ Meeting in Optometry, 2012, Melbourne, Australia.

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Shila Roshani

Roshani, Shila (2011) The effect of ocular surface conditions on blink rate and completeness. Masters by Research thesis, Queensland University of Technology.

The experiments described in this thesis have attempted to investigate show of the basic eye gaze factors that influence natural blinking patterns and the interaction between various types of contact lenses and these natural blinking patterns.  As direction of gaze shifted from downward gaze to updward gaze, the number of blinks and percentage of incomplete blinks increased significantly in the bare eye.  Rigid contact lens wear caused a significant increase in the blink rate in unadapted wearers, but no significant changes were found in blink rate, blink completeness, open palpebral aperture and percentage of incomplete blinks after fitting with soft contact lenses.

Conference Proceedings (arising from thesis):

Roshani S, Collins M, Shaw A (2010) The effect of rigid contact lens wear and gaze angle on blinking patterns. In IHBI Inspires Conference, November 25-26, 2010, Gold Coast, Australia.

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Stephen Vincent

Vincent, Stephen James (2011) Ocular characteristics of anisometropia. PhD thesis, Queensland University of Technology.

Awarded: QUT Outstanding Thesis Award for 2011

This thesis investigated a range of biometric, optical and mechanical properties of anisometropic eyes (with and without amblyopia) with the aim of improving our current understanding of asymmetric refractive error development.  The results show that a high degree of symmetry exists between the fellow eyes on non-amblyopic myopic anisometropes for a range of biomechanical, biometric and optical parameters for different levels of accommodation and following near work.  These findings suggest that further research into the association between ocular dominance, choroidal thickness and higher-order aberrations with ansiometropia may improve our understanding of refractive error development.

Publications (arising from thesis):

Vincent, Stephen, Collins, Michael J., Read, Scott A., Carney, Leo G., & Yap, Maurice (2011) Interocular symmetry in myopic anisometropia. Optometry and Vision Science88(12), pp. 1454-1462.

Vincent, Stephen J., Collins, Michael J., Read, Scott A., & Carney, Leo G. (2012) Monocular amblyopia and higher order aberrations. Vision Research66, pp. 39-48.

Vincent, Stephen J., Collins, Michael J., Read, Scott A., Carney, Leo G., & Yap, Maurice K.H. (2013) Corneal changes following near work in myopic anisometropia. Ophthalmic And Physiological Optics33(1), pp. 15-25.

Vincent, Stephen J., Collins, Michael J., Read, Scott A., & Carney, Leo G. (2013) Retinal and choroidal thickness in myopic anisometropia. Investigative Ophthalmology and Visual Science54(4), pp. 2445-2456.

Vincent, Stephen J., Collins, Michael J., Read, Scott A., & Carney, Leo G. (2014) Myopic anisometropia : ocular characteristics and aetiological considerations. Clinical and Experimental Optometry97(4), pp. 291-307.

Conference Proceedings (arising from thesis):

Vincent, Stephen, Collins, Michael J., Read, Scott A., & Carney, Leo G. (2010) Ocular characteristics in myopic anisometropia. In 88th Annual Meeting American Academy of Optometry, 17-20 November 2010, San Francisco, CA.

Vincent, Stephen, Collins, Michael J., Read, Scott A., & Carney, Leo G. (2012) Corneal changes following near work in myopic anisometropia. In 14th International Cornea and Contact Lens Congress, 12-15 October 2012, Sydney, NSW. (Unpublished)

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Garima Tyagi

Tyagi, Garima (2011) Ocular surface changes with short-term contact lens wear. PhD thesis, Queensland University of Technology.

This thesis presents a series of experiments that investigate the mechanical and physiological effects of the short-term use of contact lenses on anterior and posterior corneal topography, corneal thickness, the eyelids, tarsal conjunctiva and tear film surface quality.  These experiments showed that a variety of changes can occur in the anterior eye as a result of the short-term use of a range of commonly used contact lens types.  These short-term changes in the anterior eye are potential markers for further long term changes and the relative differences between lens types that we have identified provide an indication of areas of contact lens design and manufacture that warrant further development.

Publications (arising from thesis):

Tyagi G, Collins M, Read S and Davis B (2010). Regional changes in corneal thickness and shape with soft contact lenses. Optometry and Vision Science, 87(8):567-575.

Tyagi, Garima, Alonso-Caneiro, David, Collins, Michael J., & Read, Scott A. (2012) Tear film surface quality with rigid and soft contact lenses. Eye and Contact Lens38(3), pp. 171-178.

Tyagi, Garima, Collins, Michael J., Read, Scott A., & Davis, Brett A. (2012) Corneal changes following short-term rigid contact lens wear. Contact Lens and Anterior Eye35(3), pp. 129-136.

Conference Proceedings (arising from thesis):

Tyagi G, Collins M, Read S, Davis B. “Soft contact lens wear and regional changes in corneal thickness and topography”. American Academy of Optometry, San Francisco, 19th November 2010.

Tyagi G, Collins M, Read S, Davis B. “Corneal topography after short term use of RGP contact lenses”, American Academy of Optometry, San Francisco, 19th November 2010.

Tyagi G, Collins M, Read S, Davis B. “Corneal optical changes with short term contact lens wear”, IHBI Inspires student conference, Gold Coast, 25th November, 2010.

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David Alonso-Caneiro

Alonso-Caneiro, David (2010) Non-invasive assessment of tear film surface quality. PhD by Publication, Queensland University of Technology.

Awarded: QUT Outstanding Thesis Award for 2010

This thesis aimed to improve techniques for the assessment of tear film surface quality (TFSQ) by means of high-speed videokeratoscopy (HSV).  A set of novel image and signal processing techniques are proposed to quantify different aspects of the tear film assessment, analysis and modelling.  This technique could be a useful clinical tool to assess tear film surface quality in the future.

Publications (arising from thesis):

Alonso-Caneiro, David, Iskander, D. Robert, & Collins, Michael J. (2008) Estimating corneal surface topography in videokeratoscopy in the presence of strong signal interference. IEEE Transactions on Biomedical Engineering55(10), pp. 2381-2387.

Alonso-Caneiro, David, Iskander, Robert, & Collins, Michael J. (2009) Assessment of tear film surface quality using dynamic-area high-speed videokeratoscopy. IEEE Transactions on Biomedical Engineering56(5), pp. 1473-1481.

Alonso-Caneiro, David, Iskander, Robert, & Collins, Michael J. (2009) Tear film surface quality with soft contact lenses using dynamic-area high-speed videokeratoscopy. Eye and Contact Lens: Science and Clinical Practice35(5), pp. 227-231.

Szczesna, Dorota, Alonso-Caneiro, David, Iskander, D. Robert, Read, Scott A., & Collins, Michael J. (2010) Lateral shearing interferometry, dynamic wavefront sensing, and high-speed videokeratoscopy for noninvasive assessment of tear film surface characteristics : a comparitive study. Journal of Biomedical Optics15(3), 037005-1.

Szczesna, Dorota, Alonso-Caneiro, David, Iskander, D. Robert, Read, Scott A., & Collins, Michael J. (2011) Predicting dry eye using non-invasive techniques of tear film surface assessment. Investigative Ophthalmology and Visual Science52(2), pp. 751-756.

Alonso-Caneiro, David, Turuwhenua, Jason, Iskander, D. Robert, & Collins, Michael J. (2011) Diagnosing dry eye with dynamic-area high-speed videokeratoscopy. Journal of Biomedical Optics16(7), 076012.

Conference Proceedings (arising from thesis):

Alonso-Caneiro, David, Iskander, D. Robert, & Collins, Michael J. (2008) Computationally efficient interference detection in videokeratoscopy images. In 2008 IEEE 10th Workshop on Multimedia Signal Processing, October 8-10, 2008, Cairns, Queensland.

Alonso-Caneiro, David, Szezesna, Dorota, Iskander, Robert, & Collins, Michael (2009) Context-Based Modelling of Interferometric Signals for the Assessment of Tear-Film Suface Quality.In IEEE Statistical Signal Processing, IEEE (Institute of Electrical and Electronics Engineers, Inc.), Cardiff , pp. 553-556.

Alonso-Caneiro, David, Iskander, Robert, & Collins, Michael J. (2009) Dynamic-area high speed videokeratoscopy for the assessment of tear film surface quality. In ARVO 2009 Annual Meeting : Reducing Disparity in Eye Disease and Treatment, 3-7 May 2009, Fort Lauderdale, Florida.

Iskander DR, Szczesna DH, Alonso-Caneiro D, Read SA, Collins MJ, “Predicting dry eye with noninvasive techniques of tear film surface assessment”, Investigative Ophthalmology and Visual Science, E-Abstract 3370, 2010.

Collins MJ, Szczesna DH, Alonso-Caneiro D, Iskander DR, Read SA, “Noninvasive assessment of tear film surface quality”, Investigative Ophthalmology and Visual Science, E-Abstract 3372, 2010.

Szczesna DH, Iskander DR, Alonso-Caneiro D, Read SA, Collins MJ, “Noninvasive assessment of tear film surface kinetics”, Investigative Ophthalmology and Visual Science, E-Abstract 3371, 2010.

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Fan Yi

Yi, Fan (2010) Wavefront aberrations and the depth of focus of the human eye. PhD thesis, Queensland University of Technology.

Presbyopia is an age-related problem where the eye progressively loses its ability to focus on near objects. It can be treated by optically extending the range of focus of the human eye. This PhD research investigated the range of focus in both young and old eyes and its relationship with the optical qualities of the eye. The research has led to new optical designs that show promise for providing better corrections for presbyopia.

Publications (arising from thesis):

Yi, Fan, Iskander, D. Robert, & Collins, Michael J. (2010) Estimation of the depth focus from wavefront measurements. Journal of Vision10(4), pp. 1-9.

Yi, F., Robert Iskander, D., & Collins, M. J. (2011) Depth of focus and visual acuity with primary and secondary spherical aberration. Vision Research51(4), pp. 1648-1658.

Conference Proceedings (arising from thesis):

Yi F, Iskander DR, Collins MJ, “Subjective measurement of depth of focus in keratoconus”, Investigative Ophthalmology and Visual Science, 2010; 51:E-Abstract 4971 (ARVO Annual Meeting April 2010)

Yi, F., Iskander, D. R., & Collins, M. J. (2008). Spherical aberration and the depth-of-focus in a population of normal subjects. Presented at the 4th European Meeting in Visual & Physiological Optics, Crete, Greece.

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Alyra Shaw

Shaw, Alyra J. B. (2009) Eyelid pressure on the cornea. PhD thesis, Queensland University of Technology.

Awarded: QUT Outstanding Thesis Award for 2009

The findings of this thesis have shown that the pressure exerted by the eyelids can influence the regularity of the corneal surface and the eye’s optics.  Novel methods were developed to quantify the contact region and pressure distribution between the cornea and eyelids.  The findings of this thesis are important for our understanding of the eyelids role in tear film distribution and the interaction between the eyelids and contact lenses on eye.

Publications (arising from thesis):

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2008) Corneal refractive changes due to short-term eyelid pressure in downward gaze. Journal of Cataract and Refractive Surgery34(9), pp. 1546-1553.

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2009) Eyelid pressure: inferences from corneal topographic changes. Cornea28(2), pp. 181-188.

Shaw, Alyra J., Davis, Brett A., Collins, Michael J., & Carney, Leo G. (2009) A technique to measure eyelid pressure using piezoresistive sensors. IEEE Transactions on Biomedical Engineering56(10), pp. 2512-2517.

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2010) Eyelid pressure and contact with the ocular surface. Investigative Ophthalmology and Visual Science51(4), pp. 1911-1917.

Conference Proceedings (arising from thesis):

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2008) Eyelid pressure : inferences from corneal topographic changes. In The Association for Research in Vision and Ophthalmology 2008 Annual Meeting, April 27 – May 1, Fort Lauderdale, Florida, US.

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2009) Development of a method to measure upper eyelid pressure on the cornea [Abstract]. In 12th Scientific Meeting in Optometry, 28–30 September 2008, University of Auckland.

Shaw, Alyra J., Collins, Michael J., Davis, Brett A., & Carney, Leo G. (2009) The measurement of eyelid margin pressure on the ocular surface [Abstract]. In The Association for Research in Vision and Ophthalmology 2009 Annual Meeting, May 3 – 7, Fort Lauderdale, Florida, US.

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Scott Read

Read, Scott A. (2006) Corneal topography and the morphology of the palpebral fissure. PhD thesis, Queensland University of Technology.

Awarded: QUT Deans Commendation for Outstanding Thesis for 2006

This thesis shows that the cornea changes as a result of eyelid forces occurring in the majority of young subjects tested over the course of a normal working day.  The morphology of the palpebral fissure, and central and peripheral corneal topography was defined for a large population of young subjects, revealing significant associations between corneal astigmatism and the morphology of the palpebral fissure.  While the results of this thesis support a model of corneal astigmatism development based on eyelid morphology, they do not prove causation.  Further research investigating eyelid pressure and corneal rigidity is necessary to understand the exact aetiology of the magnitude and axis of corneal astigmatism.

Publications (arising from thesis):

Read, Scott A., Collins, Michael J., & Carney, Leo G. (2005) The diurnal variation of corneal topography and aberrations. Cornea24(6), pp. 678-687.

Read, Scott A., Collins, Michael J., Carney, Leo G., & Franklin, Ross J. (2006) The topography of the central and peripheral cornea. Investigative Ophthalmology and Visual Science47(4), pp. 1404-1415.

Read, Scott A., Collins, Michael J., Carney, Leo G., & Iskander, D. Robert (2006) The Morphology of the Palpebral Fissure in Different Directions of Vertical Gaze. Optometry and Vision Science83(10), pp. 715-722.

Read, Scott A., Collins, Michael J., & Carney, Leo G (2007) A review of astigmatism and its possible genesis. Clinical and Experimental Optometry90(1), pp. 5-19.

Read, Scott A., Collins, Michael J., & Carney, Leo G. (2007) The Influence of Eyelid Morphology on Normal Corneal Shape. Investigative Ophthalmology and Visual Science48(1), pp. 112-119.

Read, Scott A., Collins, Michael J., & Carney, Leo G (2007) A review of astigmatism and its possible genesis. Clinical and Experimental Optometry90(1), pp. 5-19.

Read, Scott A., Collins, Michael J., & Carney, Leo G. (2007) The Influence of Eyelid Morphology on Normal Corneal Shape. Investigative Ophthalmology and Visual Science48(1), pp. 112-119.

Conference Proceedings (arising from thesis):

Read, Scott A., Collins, Michael J., Carney, Leo G., & Iskander, D. Robert (2005) The morphology of the anterior eye in three different angles of vertical gaze. In 11th Scientific Meeting in Optometry, 27–28 September 2005, Queensland University of Technology, Brisbane, Australia.

Read, Scott A., Collins, Michael J., Carney, Leo G., & Franklin, Ross (2005) The topography of the peripheral cornea. In American Academy of Optometry Meeting, 2005, San Deigo, California.

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Tobias Buehren

Buehren, Tobias F. (2003) Corneal topography, near work and eyelid forces. PhD thesis, Queensland University of Technology.

Subtle changes in corneal shape can cause substantial changes in the optical characteristics of the eye.  This thesis has investigated the optical effects of corneal distortions caused by eyelid forces and demonstrated that several corneal higher and lower order Zernike wavefront aberrations can change following reading.  The changes in corneal shape following reading appear to be different in myopic versus emmetropic refractive error groups.

Publications (arising from thesis):

Buehren, Tobias F., Lee, Brenden J., Collins, Michael J., & Iskander, D. Robert (2002) Ocular microfluctuations and Videokeratoscopy. Cornea21(4), pp. 346-351.

Buehren, Tobias F., Collins, Michael J., & Carney, Leo G. (2003) Corneal Aberrations and Reading. Optometry and Vision Science80(2), pp. 159-166.

Buehren, Tobias F., Collins, Michael J., Loughridge, James S., Carney, Leo G., & Iskander, D. Robert (2003) Corneal topography and accommodation. Cornea22(4), pp. 311-316.

Conference Proceedings (arising from thesis):

Buehren, Tobias F., Collins, Micahel J., & Carney, Leo G. (2002) Corneal topography following reading. In Association for Research in Vision and Ophthalmology Meeting, 2002.

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Wilfred Tang

Tang, Wilfrid (2001) The relationship between corneal topography and visual performance. PhD thesis, Queensland University of Technology.

The work reported in this thesis is primarily related to the analysis of corneal topography in groups with wide ranging corneal shapes and the relationship between corneal shape and visual performance.  Topographic data was fitted with Zernike polynomials, and corneal measurements were also used to derive the total residual refractive power of the cornea using a root mean square (RMS) index.  RMS was found to be significantly correlated with visual performance in these subjects.

Publications (arising from thesis):

Tang, Wilfred, Collins, Michael J., Carney, Leo G., & Davis, Brett A. (2000) The Accuracy and Precision Performance of Four Videokeratoscopes in Measuring Test Surfaces. Optometry and Vision Science77(9), pp. 483-491.

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Michael Sydenham

Sydenham, Michael Matthew (1995) The measurement of ultraviolet radiation at the surface of the eye. PhD thesis, Queensland University of Technology.

While there is a clear role for ultraviolet (UV) radiation in the pathogenesis of certain ocular disorders, the relative amount of UV radiation which reaches the eye, and its relationship to the site and incidence of UV-induced ocular pathology is less clear.  The aim of this thesis was to develop a contact lens dosimeter for the assessment of ocular UV radiation exposure.  Two polysulphone contact lens designs are proposed for ocular UV dosimetry, which will provide a new research tool for ocular UV dose assessment.

Publications (arising from thesis):

Sydenham, Michael M., Collins, Michael J., & Hirst, Lawrence (1994) The effectiveness of poly(allyl diglycol carbonate(CR39) for low-dose solar ultraviolet dosimetry. Photochemistry and Photobiology59, pp. 58-65.

Sydenham, Michael M., Collins, Michael J., & Hirst, Lawrence W. (1997) Measurement of ultraviolet radiation at the surface of the eye. Investigative Ophthalmology and Visual Science38(8), pp. 1485-1492.

Conference Proceedings (arising from thesis):

Sydenham, Michael M., Collins, Michael J., & Hirst, Lawrence W. (1994) The suitability of CR-39 and polysulphone for ocular solar ultraviolet (UV) dosimetry. In Association for Research in Vision and Ophthalmology Annual Meeting, 1-6 May 1994, Sarasota, Florida.

Sydenham, Michael M., Collins, Michael J., & Hirst, Lawrence W. (1996) The development and application of a polysulphone contact lens dosimeter. In XII International Congress of Eye Research. Experimental Eye Research, 1996, Ridgefield, New Jersey.

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Thomas Tenkate

Tenkate, Thomas Daniel (1994) Ultraviolet radiation exposure of welders. Masters by Research thesis, Queensland University of Technology.

Ultraviolet radiation is a by-product of the welding process, and can produce acute and chronic effects on the eyes and skin.  The personal ultraviolet radiation exposure levels of a group of welders and nearby workers was estimated using a photosensitive polymer film (polysulphone) which was attached to eye protection, worker’s clothing, and throughout the work area.  The results of this study suggest that welders require ocular protection in addition to welding helmets, and that all exposed skill surfaces of workers in a welding environment should also be protected.

Publications (arising from thesis):

Tenkate, Thomas D. & Collins, Michael J. (1990) A survey of symptoms and eye safety practices among welders. Clinical and Experimental Optometry73(3), pp. 79-85.

Tenkate, Thomas D. & Collins, Michael J. (1997) Personal ultraviolet radiation exposure of workers in a welding environment. American Industrial Hygiene Association Journal58(1), pp. 33-38.

Tenkate, Thomas D. & Collins, Michael J. (1997) Angles of entry of ultraviolet radiation into welding helmets. American Industrial Hygiene Association Journal58(1), pp. 54-56.

Conference Proceedings (arising from thesis):

Tenkate, Thomas D. & Collins, Michael J. (1994) Ultraviolet radiation infiltration into welding helmets. In Australian Institute of Occupational Hygeinists, Proceedings of the Thirteenth Annual Conference 1994.

Tenkate, Thomas D. & Collins, Michael J. (1994) Ultraviolet radiation exposure in a welding environment. In Australian Institute of Occupational Hygeinists, Proceedings of the Thirteenth Annual Conference 1994.
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