Full metadata record
DC FieldValueLanguage
dc.contributorSchool of Optometryen_US
dc.contributor.advisorKee, Chea-su (SO)en_US
dc.creatorKang, Byung Soo-
dc.identifier.urihttps://theses.lib.polyu.edu.hk/handle/200/10818-
dc.languageEnglishen_US
dc.publisherHong Kong Polytechnic Universityen_US
dc.rightsAll rights reserveden_US
dc.titleThe effect of high myopia on corneal changes in chickenen_US
dcterms.abstractPurpose: To investigate changes in corneal biometric and biomechanical parameters by applying custom-made instruments and proteomic analysis during the development of high myopia in form-deprivation treated chicks. Methods: White Leghorn chicks (Gallus gallus domesticus) were used. Form-deprivation myopia was induced by occluding the right eyes for a week from day 5 post-hatching, while left eyes served as fellow contralateral controls. Refractive status, ocular axial dimensions, and corneal curvature were measured by a modified Hartinger refractometer, high-frequency A-scan ultrasonography, and custom-made videokeratography, respectively. Experiment 1 (Chapter 2): The applicability of a custom-made air-jet optical coherence tomography system for corneal biomechanics measurement on chicks was tested. An intraocular-pressure control system was also validated. Experiment 2 (Chapter 3): The applicability of a custom-made optical-coherence­tomography-indentation probe system for corneal biomechanics measurement on chicks was tested. The relationship between corneal biomechanical properties (tangent modulus and stiffness coefficient) and ocular biometric parameters was investigated. Experiment 3 (Chapter 4): Generation and application of the chicken corneal proteome for a screening of differentially expressed corneal proteins during the change of corneal biometric and biomechanical properties in high myopia. Results: Experiment 1 (Chapter 2): The custom-made air-jet optical coherence system was applicable for the measurement of chicks' eyes and a reduced corneal stiffness coefficient was found in form-deprivation treated eyes (mixed two-way ANOVA; main effect of myopia treatment: F (1, 24)= 17.13, p<0.001). Experiment 2 (Chapter 3): The custom-made optical-coherence-tomography­indentation probe system was shown to be reliable and valid for corneal biomechanics measurements. Highly myopic chicks had a reduced corneal tangent modulus and stiffness coefficient (mixed two-way ANOVAs, all p<0.01). A significant correlation was observed between corneal biomechanical properties and ocular biometric parameters (with spherical equivalent refractive error, all r>+0.52, p<0.05; with vitreous chamber depth, all r>-0.61, p<0.05). Experiment 3 (Chapter 4): A large corneal proteome of the chick (n= 2096) was established (1 % Global FDR). Using this first reported spectral library for highly myopic chicks, three upregulated (Reactive intermediate imine deaminase A homolog, Cadherin-1, and RuvB-like helicase) and five downregulated (Fibrinogen alpha chain, Fibrinogen beta chain, Fibrinogen gamma chain, Alpha-2­macroglobulin-like 4, and Chromobox 3 protein) proteins were identified following application of mass-spectrometry based proteomic analysis (p<0.05). Conclusions: These results demonstrated significant changes in the corneal biometric and biomechanical properties as a result of the development of high myopia in chicks. The establishment of a corneal proteome in chicken provides research opportunities to study mechanisms potentially involved in corneal reshaping.en_US
dcterms.extent158 pages : color illustrationsen_US
dcterms.isPartOfPolyU Electronic Thesesen_US
dcterms.issued2020en_US
dcterms.educationalLevelPh.D.en_US
dcterms.educationalLevelAll Doctorateen_US
dcterms.LCSHMyopiaen_US
dcterms.LCSHCorneaen_US
dcterms.LCSHHong Kong Polytechnic University -- Dissertationsen_US
dcterms.accessRightsopen accessen_US

Files in This Item:
File Description SizeFormat 
5240.pdfFor All Users3.5 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show simple item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/10818