Comparison of Retinal Nerve Fiber Layer and Optic Disc Imaging for Diagnosing Glaucoma in Patients Suspected of Having the Disease

Abstract

Purpose-To compare retinal nerve fiber layer (RNFL) and optic disc topographic imaging for detection of optic nerve damage in patients suspected of having glaucoma. Design-Observational cohort study.Participants-A cohort of 82 patients suspected of having glaucoma based on the appearance of the optic nerve.Methods-All patients were imaged using the GDx VCC scanning laser polarimeter and HRT (software version 3.0) confocal scanning laser ophthalmoscope. All patients had normal standard automated perimetry visual fields at the time of imaging and were classified based on history of documented stereophotographic evidence of progressive glaucomatous change in the appearance of the optic nerve occurring before the imaging sessions.Main Outcome Measures-Areas under the receiver operating characteristic (ROC) curves were used to evaluate the diagnostic accuracies of GDx VCC and the HRT.Results-Forty eyes with progressive glaucomatous optic nerve change were included in the glaucoma group, and 42 eyes without any evidence of progressive damage to the optic nerve followed untreated for an average time of 8.97±3.08 years were included in the normal group. The area under the ROC curve for the best parameter from GDx VCC (nerve fiber indicator [NFI]) was significantly larger than that of the best parameter from the HRT (rim volume) (0.83 vs. 0.70; P = 0.044). The NFI parameter also had a larger ROC curve area than that of the contour line-independent parameter glaucoma probability score (0.83 vs. 0.68; P = 0.023). Assuming borderline results as normal, the Moorfields regression analysis classification had a sensitivity of 48% for specificity of 69%. For a similar specificity (70%), the parameter NFI had a significantly larger sensitivity (83%) (P = 0.003).Conclusions-Retinal nerve fiber layer imaging with GDx VCC had a superior performance versus topographic optic disc assessment with the HRT for detecting early damage in patients suspected of having glaucoma. For glaucoma diagnosis, these results suggest that GDx VCC may offer advantage over the HRT when these tests are combined with clinical examination of the optic nerve.To diagnose disease, a clinician integrates the constellation of symptoms and/or signs of a presenting patient and then assigns a level of certainty regarding its presence. In the case of glaucoma evaluation, the process generally starts with the medical interview and history. It is NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript followed by clinical examination, which generally includes slit-lamp examination, intraocular pressure (IOP) measurement, and optic nerve examination. After this information is collected, the clinician hypothesizes about the chance that glaucoma is present and can order additional tests, such as the visual field (VF).It is not unusual for a patient to present with suspicious appearance of the optic disc and normal or inconclusive VF tests. In this situation, additional testing, such as optic disc and/or retinal nerve fiber layer (RNFL) imaging,...

Objective Assessment of Progression after Acute Primary Angle Closure Using HRT and GDx

“…Rim volume, unlike rim area, takes into account the threedimensional nature of the ONH rim. Thus rim volume may be considered a better parameter in assessing subtle ONH rim changes [19,20]. This is in keeping with Chai et al where a reduction in rim volume was observed after a single APAC attack [13].…”

Influence of Disc Size on Optic Nerve Head versus Retinal Nerve Fiber Layer Assessment for Diagnosing Glaucoma

“…Although it has been reported that RNFL quantitative assessment by either the commercially available SLP with variable corneal and lens compensator (GDx-VCC, Carl Zeiss Meditec, Dublin, CA), and spectral domain OCT may perform similarly or better than topographic ONH assessment for discriminating glaucomatous from normal eyes, 21 little is known about the influence of disc size on the diagnostic accuracy of quantitative RNFL assessment.…”

Strategies to improve early diagnosis in glaucoma

“…Imaging devices provide an objective means to obtain high-resolution topographic images of the optic nerve head and RNFL and to quantify characteristics of these structures (Chang et al, 2009;Greaney et al, 2002;Jaffe and Caprioli, 2004;Leung et al, 2009Leung et al, , 2010Medeiros et al, 2004bMedeiros et al, , 2005bMedeiros et al, , 2008Mwanza et al, 2012;Naithani et al, 2007;Wollstein et al, 1998Wollstein et al, , 2000Zangwill et al, 2001). In addition, imaging devices contain normative databases that allow one to determine the probability that observed measurements are within the normal range and to potentially detect glaucoma at an earlier stage ( Fig.…”

“…1), confocal scanning laser ophthalmoscopy (CSLO), and scanning laser polarimetry (SLP), that obtain objective quantitative measurements of ocular structure and can detect glaucoma at an earlier stage (Chang et al, 2009;Greaney et al, 2002;Huang et al, 1991;Leung et al, 2009Leung et al, , 2010Medeiros et al, 2004bMedeiros et al, , 2005bMedeiros et al, , 2008Mwanza et al, 2012;Naithani et al, 2007;Weinreb et al, 2014;Wollstein et al, 1998Wollstein et al, , 2000Zangwill et al, 2001). In addition to evaluating the optic nerve head and RNFL, imaging devices have also recently been used to evaluate inner layers of the glaucomatous macula Mwanza et al, 2012Mwanza et al, , 2014.…”