Diagnostic Innovations in Glaucoma Study (DIGS)

A prospective, longitudinal observational cohort study evaluating the relationship between changes in the structure of the eye and the vision loss caused by glaucoma. There are two main parts to the study: 1) Visual Function and 2) Optic Nerve Structure

The purpose of the study is:

1. To further determine the nature of vision loss and optic nerve structural change associated with glaucoma. Using recently developed psychophysical and imaging techniques, we will continue use of a multivariate approach for analysis of the functional and structural changes associated with glaucoma to delineate further the relationship of these changes to the underlying physiological mechanisms associated with magnocellular, small bistratified "blue-yellow", and parvocellular neural pathways.
2. To evaluate and improve new diagnostic and monitoring techniques encompassing measures of visual function and optic nerve and retina nerve fiber layer structure and to compare the rate and patterns of progression of glaucomatous damage
3. To improve techniques for evaluation of current management and new therapies for glaucoma as they become available. We will expand our analysis using multivariate techniques incorporating visual function, optic nerve structure, and various risk factors to improve detection of true change.
4. To determine the quantitative temporal relationships between recognizable optic nerve damage and measurable visual field loss. Using new techniques with improved sensitivity, the detection and monitoring of early optic disc defects may provide profiles of people at risk for developing glaucomatous visual function loss thus better defining target populations for treatment.

SPECIFIC AIMS OF DIGS: STRUCTURAL ASSESSMENT Overall Aim: Develop improved methods to 1) detect the onset and progression of structural damage due to glaucoma, and 2) to measure the rate of glaucomatous progression and its determinants, and 3) characterize the relationship between structural and functional change over time. In addition, a major goal of this research is to develop methods to shorten the time frame needed to identify and verify progression of optic disc and retinal nerve fiber damage.

SPECIFIC AIMS OF DIGS: VISUAL FUNCTION Overall Aim: Develop improved measures to detect the onset and progression of glaucoma, to assess treatment effectiveness, and to validate predictive genetic testing using psychophysical measures of visual function.

Adults

• Healthy individuals
• Persons at risk for or with primary open angle glaucoma

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• Stamper R. L., Sample P. A. and Girkin C. A. (Eds.). (2003). Assessing Visual Function in Clinical Practice. Ophthalmology Clinics of North America, Vol.16, Number 2. In Racette L and Sample P.A. (eds.). Short wave automated perimetry. (pp. 227 -236).
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• Zangwill LM, Chan K, Bowd C, Hao J, Lee TW, Weinreb RN, Sejnowski TJ, Goldbaum MH. Heidelberg retina tomograph measurements of the optic disc and parapapillary retina for detecting glaucoma analyzed by machine learning classifiers. Invest Ophthalmol Vis Sci. 2004 Sep;45(9):3144-51.
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• Sample PA, Chan K, Boden C, Lee TW, Blumenthal EZ, Weinreb RN, Bernd A, Pascual J, Hao J, Sejnowski T, Goldbaum MH. Using unsupervised learning with variational bayesian mixture of factor analysis to identify patterns of glaucomatous visual field defects. Invest Ophthalmol Vis Sci. 2004 Aug;45(8):2596-605.
• Medeiros FA, Sample PA, Weinreb RN. Frequency doubling technology perimetry abnormalities as predictors of glaucomatous visual field loss. Am J Ophthalmol. 2004 May;137(5):863-71.
• Medeiros FA, Zangwill LM, Bowd C, Weinreb RN. Comparison of the GDx VCC scanning laser polarimeter, HRT II confocal scanning laser ophthalmoscope, and stratus OCT optical coherence tomograph for the detection of glaucoma. Arch Ophthalmol. 2004 Jun;122(6):827-37.
• Mohammadi K, Bowd C, Weinreb RN, Medeiros FA, Sample PA, Zangwill LM. Retinal nerve fiber layer thickness measurements with scanning laser polarimetry predict glaucomatous visual field loss. Am J Ophthalmol. 2004 Oct;138(4):592-601.
• Balasubramanian M, Kriegman DJ, Bowd C, Holst M, Weinreb RN, Sample PA, Zangwill LM. Localized glaucomatous change detection within the proper orthogonal decomposition framework. Invest Ophthalmol Vis Sci. 2012 Jun 14;53(7):3615-28. Print 2012 Jun.
• Medeiros FA, Zangwill LM, Mansouri K, Lisboa R, Tafreshi A, Weinreb RN. Incorporating risk factors to improve the assessment of rates of glaucomatous progression. Invest Ophthalmol Vis Sci. 2012 Apr 24;53(4):2199-207. Print 2012 Apr.
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• Medeiros FA, Leite MT, Zangwill LM, Weinreb RN. Combining structural and functional measurements to improve detection of glaucoma progression using bayesian hierarchical models. Invest Ophthalmol Vis Sci. 2011 Jul 29;52(8):5794-803. Print 2011 Jul.

Inclusion Criteria:

• Open angles
• Best-corrected acuity of 20/40 or better
• Spherical refraction within + 5.0 D, and cylinder within + 3.0 D with plus OR minus cylinders
• ≥ 18 years old
• A family history of glaucoma is allowed
• Ability for study to acquire adequate or better quality stereophotographs
• Ability to do reliable standard Humphrey 30-2 or 24-2 visual fields
• Participants with glaucoma or at risk for glaucoma or healthy controls

Exclusion Criteria:

• History of intraocular surgery (except for uncomplicated cataract surgery)
• Non-glaucomatous secondary causes of elevated IOP (e.g. iridocyclitis, trauma)
• Other intraocular eye disease
• Other diseases affecting visual field (e.g. pituitary lesions, demyelinating diseases, HIV+ or AIDS, or diabetic retinopathy), with medications known to affect visual field sensitivity
• Problems other than glaucoma affecting color vision.