advertisement
Abstract #55213 Published in IGR 15-4
The locations of circumpapillary glaucomatous defects seen on frequency-domain OCT scans
Hood DC; Wang DL; Raza AS; De Moraes CG; Liebmann JM; Ritch RInvestigative Ophthalmology and Visual Science 2013; 54: 7338-7343
PURPOSE: To examine the locations of local glaucomatous damage around the optic disc as seen in the circumpapillary retinal nerve fiber layer (RNFL) on frequency domain optical coherence tomography (fdOCT). METHODS: Optic disc fdOCT volume scans from 54 healthy control eyes and 114 patient eyes, classified as suspected or mild glaucoma, were analyzed. All patient eyes had 24-2 visual fields (VFs) with mean deviations better than -5.5 dB. By hand-correcting automated segmentation, the RNFL thickness profile was obtained for a circumpapillary circle. RNFL defects were defined as regions where the patient's RNFL thickness fell below the 99% confidence limit of control values. The location of a defect was defined as the point of greatest difference between the patient's thickness and the 99% limit. The locations of major blood vessels (BVs) were marked, and separated into superior-nasal (SN), superior-temporal (ST), inferior-temporal (IT), and inferior-nasal (IN) groups. RESULTS: Of the 114 patient eyes, 45 exhibited a total of 75 RNFL defects. The locations of these defects clustered around the ST, SN, and IT, but not the IN BVs. CONCLUSIONS: The absence of defects in the IN region indicates that the locations of local defects are not simply related to either BV location or RNFL thickness. The local defects in the ST and IT regions can be related to arcuate defects seen on 24-2 and 10-2 VFs. However, the defects in the SN region suggest the presence of VF defects that may be overlooked because they fall largely outside the 24-2 test grid.
Full article
Classification:
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
2.14 Optic disc (Part of: 2 Anatomical structures in glaucoma)
6.9.2.2 Posterior (Part of: 6 Clinical examination methods > 6.9 Computerized image analysis > 6.9.2 Optical coherence tomography)