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Updated: Jan 26, 2026
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Imaging Ca2+ Dynamics in Cone Photoreceptor Axon Terminals of the Mouse Retina
Published on: May 6, 2015
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A 2-Year Longitudinal Study of Normal Cone Photoreceptor Density
Kevin Jackson1, Grace K Vergilio1,2, Robert F Cooper1,3
1Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
Investigative Ophthalmology & Visual Science
|April 4, 2019
Summary
Normal cone density remains stable over two years. Minimizing image distortions reduces variability in cone density measurements, crucial for retinal disease trials.
Area of Science:
- Ophthalmology
- Retinal Imaging
- Cellular Biology
Background:
- Adaptive optics scanning light ophthalmoscopy (AOSLO) offers cellular-level quantification of retinal disease progression.
- Longitudinal studies tracking cone density changes are limited.
Purpose of the Study:
- To investigate the variability of cone density measurements in normal subjects over a 2-year period.
- To assess the utility of cone density as a biomarker for retinal disease progression.
Main Methods:
- A prospective, longitudinal study involving 14 eyes of 9 healthy subjects.
- Confocal AOSLO imaging at five retinal locations at baseline and 2-year follow-up.
- Affine image registration to minimize intraframe distortions and extract cone density.
Main Results:
- Mean baseline cone densities ranged from 87,300 to 18,200 cones/mm² across different retinal locations.
- The mean difference in cone density over 2 years was minimal, with lower variability in affine-registered images.
- Variability in cone density measurements decreased with minimized inter-visit image distortions.
Conclusions:
- Normal cone density shows no significant change over a 2-year period.
- Minimizing image distortions is essential for reducing intervisit variability in cone density measurements.
- Cone density variability must be accounted for in longitudinal clinical trials for retinal disease progression.
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