City Research Online

A study of the role of advanced technologies in glaucoma case-finding

Dabasia, Priya (2014). A study of the role of advanced technologies in glaucoma case-finding. (Unpublished Doctoral thesis, City University London)


In the UK, 11,000 new cases of open angle glaucoma (OAG) are diagnosed annually in people aged 40 to 70 years. However, two--‐thirds of UK OAG cases may remain undiagnosed, highlighting the need for improved detection. UK optometrists generate more than 95% of referrals for suspected glaucoma and ocular hypertension. Case--‐ detection of glaucoma may be improved by using screening tests with better diagnostic accuracy, but standardised protocols for advanced technologies used alone, or in combination, to detect glaucoma are lacking.

Chapter 2 reports on two cross--‐sectional surveys of UK community optometrists, determining the equipment and information technology (IT) used in optometric practice, and exploring the rationale behind the uptake of ophthalmic equipment and IT. UK optometrists are increasingly investing in new ophthalmic equipment and IT, including the latest technology. Longitudinal comparisons with previous surveys revealed an increase in use of Optical coherence tomography (OCT), Goldmann/ Perkins tonometry and pachymetry. Variations in responses reflected differences in General Ophthalmic Services provision across the UK and involvement in community enhanced services. There was general agreement that specialised equipment enhances clinical care and permits increased involvement in enhanced services, but initial costs and ongoing maintenance can be a financial burden.

Chapter 3 summarises a prospective cross--‐sectional study investigating the diagnostic accuracy of four advanced technologies for detecting POAG, used alone and in combination, in a representative sample (N=505) of the UK primary care population aged ≥60 years, and compared to a reference standard ophthalmic examination. Structural imaging using the iVue SD--‐OCT provided better discrimination between POAG and non--‐POAG/ non--‐OHT subjects than either visual function test (Frequency Doubling Technology or Moorfields Motion Displacement Threshold). The low specificity of visual function tests precludes their use in isolation, but their use together with objective evaluation of optic nerve head structure by SD--‐OCT should improve case--‐detection of glaucoma.

Chapter 4 describes a case--‐control study (N=78) evaluating the diagnostic effectiveness of two slit--‐lamp based techniques (van Herick and Smith’s) and imaging--‐based systems (Pentacam and Visante OCT) when compared to the reference standard gonioscopic observation, to screen for individuals at--‐risk of angle closure glaucoma (ACG). Overall, the van Herick test and Visante OCT, used either alone or in combination, showed best discrimination between narrow and open angles. Recording of either the temporal or nasal van Herick grade would be sufficient for case--‐finding in at--‐risk individuals.

Chapter 5 summarises preceding chapters and details recommendations for future research.

Publication Type: Thesis (Doctoral)
Subjects: R Medicine > RE Ophthalmology
Departments: School of Health & Psychological Sciences > Optometry & Visual Sciences
Doctoral Theses
School of Health & Psychological Sciences > School of Health & Psychological Sciences Doctoral Theses
Text - Accepted Version
Download (31MB) | Preview



Downloads per month over past year

View more statistics

Actions (login required)

Admin Login Admin Login