Contrast sensitivity loss in patients presenting with cataract and early stage glaucoma using methods suitable for clinical use

Abstract

Glaucoma is an insidious progressive disease that leads to a permanent loss of vision if left untreated. The development of methods for early detection of the disease is essential as early diagnosis and treatment significantly reduces the risk of sight loss. Contrast sensitivity (CS) testing has shown the potential to detect glaucoma in its early stage. However, as glaucoma is mainly a disease of the elderly, comorbidity with cataract is common. The extent to which cataractous changes in glaucoma patients affect grating CS tests and how these effects depend on the type and severity of cataract is not known. This study aimed to investigate CS loss in glaucoma and cataract patients and to assess whether these tests could provide the basis for improved clinical diagnosis.

The study demonstrates that grating CS tests can be performed using TFT flat panel monitors which are largely available in clinical settings after appropriate measurements to show the suitability of each particular monitor for visual research.

The thesis presents experimental evidence that CS for both stationary and flickering gratings is significantly reduced in patients with early glaucoma and cataract when compared to age-matched controls with cataract. This suggests that both tests can separate neural and optical loss and are thus sensitive methods for early glaucoma detection in the presence of a cataract. The results of this thesis show that grating CS is not only a sensitive test for early glaucoma detection but might also be a useful tool for monitoring the disease. Finally, this thesis shows that glaucoma patients experience significant glare which is related to the disease severity as characterised by optic disc topography.

In conclusion, this work has shown that CS testing with stationary and/or flickering gratings is capable of differentiating patients with glaucoma from cataract controls and that such a testing procedure can be easily implemented in clinical practiceusing TFT flat panel monitors.

Date of Award	Nov 2013
Original language	English
Supervisor	Margarita Vidinova (Supervisor), Barbara Pierscionek (Supervisor), Jan Lauritzen (Supervisor) & Raymond Beirne (Supervisor)