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Abstract #59311 Published in IGR 16-3
Influence of the Disc-Fovea Angle on Limits of RNFL Variability and Glaucoma Discrimination
Amini N; Nowroozizadeh S; Cirineo N; Henry S; Chang T; Chou T; Coleman AL; Caprioli J; Nouri-Mahdavi KInvestigative Ophthalmology and Visual Science 2014; 55: 7332-7342
PURPOSE: To determine factors affecting the disc-fovea angle (DFA), and to test the hypotheses that adjusting for DFA improves limits of retinal nerve fiber layer (RNFL) variability in normal subjects or enhances performance of RNFL measures for glaucoma detection. METHODS: Disc-fovea angle was measured on scanning laser ophthalmoscope fundus images from 170 eyes (110 normal and glaucoma subjects). The DFA measurements were repeated in 24 eyes. The relationship between DFA and various anatomic variables was explored. Main outcome measures were changes in 95% RNFL prediction limits or glaucoma discrimination after adjusting for DFA. We also explored the angle between temporal raphe and horizontal meridian in 19 eyes with nasal field defects limited to one hemifield. RESULTS: Average mean deviation and DFA were -0.1 (±1.2) dB and -6.6° (±3.4°) and -4.1 (±3.3) dB and -7.9° (±3.9°) in the control and glaucoma groups, respectively (P < 0.001 and = 0.029). The average difference between DFA repeat measurements was 2.0° (±1.8°). Predictors for DFA were female sex (P = 0.004), smaller disc area (P = 0.006), and glaucoma diagnosis (P = 0.019). The absolute change in sectoral RNFL thickness was 6.1 (±3.9) and 4.6 (±3.1) μm in control and glaucoma subjects, respectively. Retinal nerve fiber layer prediction limits improved in 5, 9, and 10 o'clock sectors (P < 0.02). Discrimination ability for the best-performing RNFL sector did not improve (P = 0.936). The average angle between temporal raphe and horizontal meridian was 0.8° (±0.8°). CONCLUSIONS: Disc-fovea angle measurements demonstrated fair intersession repeatability. While adjusting for DFA improved RNFL prediction limits in some sectors, it did not enhance glaucoma detection.
Glaucoma Division, Stein Eye Institute, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, California, United States.
Full articleClassification:
6.9.1.1 Confocal Scanning Laser Ophthalmoscopy (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.1 Laser scanning)
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
