Datasets available in the first release of GDP. Each of the three datasets follows a progression through glaucoma. Both optic nerve head and retinal expression data are represented within each dataset . (a) Morphological dataset. Glaucoma developing DBA/2J samples (white boxes) and strain-matched D2-Gpnmb+ no glaucoma control samples (grey box). Stages of glaucoma were determined morphologically by assessing optic nerve damage just behind the orbit (see Methods and [11,15,34]). (b) Molecular ONH dataset. Hierarchical clustering using the expression levels of a set of glaucoma specific genes grouped the optic nerve heads into 5 molecularly defined stages. Stages 1, 2 and 3 represent early states of glaucoma, which precede morphologically detectable glaucoma and so were not previously distinguishable using conventional analyses. Stages 4 and 5 contain eyes with moderate and severe optic nerve damage respectively. (c) Molecular retina dataset. A similar hierarchical clustering was performed using the retinal expression data. Four stages of disease were identified with stages R1 and R2 not previously detectable using morphological analysis. Stages R3 and R4 contain eyes with moderate and severe optic nerve damage respectively. Optic nerve heads and retinas were assessed from the same set of eyes.
Howell et al. BMC Genomics 2011 12:429 doi:10.1186/1471-2164-12-429