Abstract
Purpose :
Adaptive optics-scanning light ophthalmoscopy (AO-SLO) is a potential technique for following local progression of retinal nerve fiber layer (RNFL) bundle damage.[1,2] To assess the feasibility of detecting glaucomatous RNFL progression with AO-SLO imaging, patients with arcuate defects near fixation were studied.
Methods :
Four eyes of 4 glaucoma patients with arcuate defects within the superior macular region on 10-2 visual fields were imaged using a prototype AO-SLO.[3] Each patient was tested at least twice, with an average time of 16.1 months between visits (range 14.8-18.5 months). AO-SLO images of the RNFL bundles were obtained near the edge of the optic disc and at the macular region near the fovea, as previously described (Fig 1a).[1,2] These images were montaged and co-registered with a fundus photograph. The AO-SLO images were compared across test dates after aligning the images with corresponding blood vessels.
Results :
Three of the 4 eyes displayed progression of the RNFL bundle defect in the inferior temporal region of the disc. In eye #1, a defect increased in width by about 30 µm after 18.5 months (Fig. 1b,c). This finding was replicated on a third scan 4.6 months later and was corroborated by RNFL bundle thinning seen in the inferior macular region, along the same arcuate path (Fig. 1d,e). In eye #2, there was widening of the abnormal region in the inferior temporal region of the disc by approximately 50 µm after 14.8 months. In eye #3, there was slight widening of the abnormal region by about 40 µm, and thinning in the corresponding region of the macular images after 14.9 months. In eye #4, the circumpapillary defect along the inferior arcuate defect showed good reproducibility, but not progression (Fig. 2b,c).
Conclusions :
AO-SLO imaging shows promise for following subtle local progression of individual RNFL bundle damage. Three of the 4 eyes showed evidence of progression within 14.8 to 18.5 months. The results also point to good reproducibility of AO-SLO images in regions where progression was not detected. 1. Chen et al, IOVS 2015; 2. Hood et al, TVST 2015 3. Dubra, Sulai, Biomed Opt Exp. 2011.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.