Correlation between perimetric indices and retinal nerve fibre layer thickness by OCT and GDX VCC in primary open angle glaucoma.

Suma Elangovan, - (2007) Correlation between perimetric indices and retinal nerve fibre layer thickness by OCT and GDX VCC in primary open angle glaucoma. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION: Glaucoma is defined as a disturbance of the structural and functional integrity of the optic nerve that can usually be arrested or diminished by adequate lowering of the intraocular pressure. It is among the leading causes of blindness in the developing world and a major health problem in the developed world. World Health Organization Statistics, published in 1995 indicates that glaucoma accounts for blindness in 5.1 million persons or 13.5% of global blindness. AIMS AND OBJECTIVES: To evaluate the correlation between the Retinal nerve fibre layer parameters(RNFL) analysed by OCT and GDx VCC and the global perimetric indices obtained with octopus perimetry. To establish whether structural parameters provided by optical coherence tomography (OCT ) and GDx VCC can be used to reflect functional damage in the visual field. To evaluate the relationship between the RNFL parameters measured using OCT and GDx VCC. MATERIALS AND METHODS: This was a cross sectional study, prospectively planned. 67 eyes of 34 glaucoma patients attending glaucoma clinic were included in this study. The study was carried out in Glaucoma clinic, Regional Institute of Ophthalmology and Government Eye Hospital, Chennai between March 2005 and July 2006. DISCUSSION: This study was designed with the major objective to evaluate the relationship between perimetric indices and structural changes brought out by optical coherence tomography and GDX VCC RNFL parameters and to compare the results obtained by these two methods for quantitatively assessing the RNFL(OCT and GDX VCC). CONCLUSION: Outcomes of the study: In established glaucoma patients a significant correlation exists between the global perimetric indices and the RNFL thickness . The RNFL thicknesses measured by two different investigatory modalities OCT and GDx are well correlated. Among the GDx parameters, the NFI was found to be a better indicator of visual field damage than the average thickness. In conclusion, though visual field testing is subjective, at present it cannot be replaced by imaging modalities. The newer instruments are valuable tools that have become available to provide quantitative reproducible and objective measurements of RNFL thickness. Thus, structural information provided by the OCT and GDx and functional information provided by the field analysis are both important and complementary to each other.

Item Type: Thesis (Masters)
Uncontrolled Keywords: primary open angle glaucoma; perimetric indices; retinal nerve fibre layer thickness; OCT; GDX VCC
Subjects: MEDICAL > Ophthalmology
Depositing User: Devi S
Date Deposited: 11 Sep 2017 08:40
Last Modified: 11 Sep 2017 08:40

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