Aspects of frequency doubling perimetry in the detection of early glaucoma
Date
2006
Authors
Landers, John Arthur W. G.
Editors
Advisors
Casson, Robert James
Journal Title
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Volume Title
Type:
Thesis
Citation
Statement of Responsibility
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Abstract
Background : Frequency Doubling Perimetry ( FDP ) is a recently developed form of perimetry, which may be more sensitive for detecting visual field loss from glaucoma
than conventional Achromatic Automated Perimetry ( AAP ). This thesis was undertaken to study aspects of FDP for the detection of early glaucoma.
Method : FDP was compared with other forms of perimetry at one point in time using one dataset ( n = 83 ) and longitudinally over a four - year period with another dataset ( n = 62 ). Several aspects were studied : ( 1 ) the ability of FDP to detect visual field loss earlier than AAP, ( 2 ) its ability to detect early functional abnormality in the presence of mild glaucomatous structural abnormality ( 3 ) visual field topography compared with other perimetry and ( 4 ) its ability to predict future field loss when only the nasal quadrants were considered.
Results : When subjects at risk of glaucoma with initial visual field loss on FDP were
followed over a three - year period, a significant proportion developed field loss with AAP, whilst those without initial FDP loss did not. FDP detected cases of early glaucomatous
optic disc damage, which had not been detected using AAP ; however, there was still a
proportion of those with abnormal optic discs which remained normal on FDP. FDP field topography was hill - shaped with the most sensitive point centrally ; however, it was
considerably flatter and more sensitive than AAP. Finally, if FDP field loss was only considered significant when it occurred within the nasal step location of the visual field, then this may improve the accuracy of glaucoma diagnosis.
Conclusion : This thesis has demonstrated that FDP is not only more sensitive than AAP in the detection of glaucomatous optic disc damage, but it is able to predict future field loss on AAP. FDP may therefore be useful in the early detection and management of glaucoma.
School/Discipline
School of Medicine
Dissertation Note
Thesis (Ph.D.)--School of Medicine, 2006.