Purchase this article with an account.
Suman Adhikari, Alex Schill, Gwen Musial, Hanieh Mirhajianmoghadam, Hope M Queener, Jason Porter; Longitudinal repeatability of in vivo cone density measurements in normal eyes from confocal and split detector adaptive optics images. Invest. Ophthalmol. Vis. Sci. 2017;58(8):1264. doi: https://doi.org/.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The ability to assess whether changes in the photoreceptor mosaic have occurred over time (such as for diseased eyes or clinical trial-related applications) depends on the longitudinal variability of the imaging and quantification techniques. We examined the intersession repeatability of cone density measurements made in normal eyes using an adaptive optics scanning laser ophthalmoscope (AOSLO).
Confocal and split detector AOSLO images of the photoreceptor mosaic were simultaneously acquired at the same retinal locations in 8 normal subjects (age: 25-38 years) across 2 different sessions separated by ≥ 6 months. Axial length was measured (Lenstar) and used to laterally scale AOSLO images. Cone densities were calculated from 0.3 mm to 3.0 mm eccentricities (0.3 mm increments) in each of four major meridians and compared (1) between corresponding confocal and split detector images at baseline and (2) in regions commonly imaged longitudinally across sessions following registration for both modalities.
Good structural correspondence was observed between confocal and split detector images of the same retinal locations. Across subjects, there were no significant differences in baseline cone density measurements between confocal and split detector images at any eccentricity in any meridian (P>.05; paired t-test). Likewise, there were no significant differences in cone density measurements made at any location between sessions for confocal or split detector images (P>.05; paired t-test). Mean intersession differences in cone density ranged from 44-600 cones/mm2 and 100-985 cones/mm2 for confocal and split detector images, respectively. The Coefficients of Repeatability for confocal and split detector images ranged from 7,318 cones/mm2 (2.4%) to 11,069 cones/mm2 (12.2%) and from 6,973 cones/mm2 (3.8%) to 10,593 cones/mm2 (11.4%), respectively.
These intersession repeatability data in normal human eyes may be used for comparison with future studies that longitudinally examine changes in cone density in eyes with retinal degeneration. The similar performance of each modality for quantifying cone density indicates that split detector AOSLO imaging may be a valuable alternative to confocal imaging, particularly in examining cones in diseased eyes with compromised outer segment structure that may not be visible in confocal images.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.
This PDF is available to Subscribers Only