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Abstract #11787 Published in IGR 7-1
Heidelberg retina tomograph disc area: Correlation with glaucoma severity, using the disc damage likelihood scale
Harasymowycz P; Xu G; Myers J; Steinmann W; Spaeth GLClinical and Surgical Ophthalmology 2004; 22: 50-53
PURPOSE: To determine the correlation of Heidelberg Retina Tomograph disc area (HRT DA) to glaucoma severity, and how the severity of glaucoma may influence this relationship. DEFINITION: The Disc Damage Likelihood Scale (DDLS) is a method of estimating the amount of optic nerve damage based on the width of the neuroretinal rim or the circumferential extent of rim absence. The DDLS takes into account the size of the optic disc and is both valid and reproducible. PATIENTS AND METHODS: In a total of 140 patients with primary open-angle glaucoma (POAG), low-tension glaucoma (LTG), and pseudoexfoliative glaucoma (PXFG) (280 eyes), both bilateral HRT DA and visual field (VF) values were reviewed for correlation. Glaucoma severity was based on optic nerve (disc damage likelihood score [DDLS]) and VF parameters (pattern standard deviation [PSD] and mean deviation [MD]). RESULTS: The mean HRT DA in the 'worse eye' was larger than that of the 'better eye' (2.12 mm2 vs. 2.02 mm2 ; paired t-test P < 0.0001). Disc area measurements varied in different stages of glaucoma, with moderate glaucomatous optic nerve damage being associated with a larger HRT DA (F = 2.58, P < 0.04). No disc area differences were found between glaucoma subtypes. CONCLUSION: In this sample population, mean optic disc area as measured by HRT was larger in eyes with worse glaucoma. The severity of glaucomatous damage may influence disc area measurement, or alternatively, optic disc area may influence the probability of clinical detection of glaucomatous optic nerve damage.
Dr. P. Harasymowycz, Department of Ophthalmology, Maisonneuve-Rosemont Hospital, 5689 Boul. Rosemont, Montreal, Que. H1T 2H1, Canada
Classification:
6.9.1 Laser scanning (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis)