OBJECTIVE: To determine the extent of preservation in the inner retina in retinitis pigmentosa (RP). METHODS: We analyzed sectioned maculae of 21 postmortem eyes with RP and 19 age-matched, normal, postmortem eyes. Eyes were divided into 2 groups: severe and moderate RP. Cell nuclei were counted in the outer nuclear, inner nuclear, and ganglion cell layers within thirty 100-microns intervals from the foveola to 1500-microns eccentricity. RESULTS: Statistically significant (P < or = .05) loss of both the outer nuclear and ganglion cell layers was present in the groups with moderate and severe RP when compared with the control groups. However, even in the group with severe RP, 30% of the ganglion cells were histologically intact. Similarly, 78% and 88% of the inner nuclear layer cells were preserved in the groups with severe and moderate RP, respectively. Different inheritance modes showed no statistically significant differences in any of the retinal layers. CONCLUSIONS: Despite a statistically significant (P < or = .05) loss of cells found in all retinal layers, a large percentage of the inner retinal neurons remained histologically intact. Current experimental therapies, such as photoreceptor transplantation and implantation of a visual prosthesis, are based on the premise that some inner retinal neurons are preserved after death of photoreceptors in RP. Our observations support this assumption.
OBJECTIVE: To determine the extent of preservation in the inner retina in retinitis pigmentosa (RP). METHODS: We analyzed sectioned maculae of 21 postmortem eyes with RP and 19 age-matched, normal, postmortem eyes. Eyes were divided into 2 groups: severe and moderate RP. Cell nuclei were counted in the outer nuclear, inner nuclear, and ganglion cell layers within thirty 100-microns intervals from the foveola to 1500-microns eccentricity. RESULTS: Statistically significant (P < or = .05) loss of both the outer nuclear and ganglion cell layers was present in the groups with moderate and severe RP when compared with the control groups. However, even in the group with severe RP, 30% of the ganglion cells were histologically intact. Similarly, 78% and 88% of the inner nuclear layer cells were preserved in the groups with severe and moderate RP, respectively. Different inheritance modes showed no statistically significant differences in any of the retinal layers. CONCLUSIONS: Despite a statistically significant (P < or = .05) loss of cells found in all retinal layers, a large percentage of the inner retinal neurons remained histologically intact. Current experimental therapies, such as photoreceptor transplantation and implantation of a visual prosthesis, are based on the premise that some inner retinal neurons are preserved after death of photoreceptors in RP. Our observations support this assumption.
Authors: Matthew R Behrend; Ashish K Ahuja; Mark S Humayun; Robert H Chow; James D Weiland Journal: IEEE Trans Neural Syst Rehabil Eng Date: 2011-04-19 Impact factor: 3.802
Authors: Douglas Yanai; Rohit R Lakhanpal; James D Weiland; Manjunatha Mahadevappa; Gretchen Van Boemel; Gildo Y Fujii; Robert Greenberg; Sean Caffey; Eugene de Juan; Mark S Humayun Journal: Trans Am Ophthalmol Soc Date: 2003
Authors: Devyani Nanduri; Ione Fine; Alan Horsager; Geoffrey M Boynton; Mark S Humayun; Robert J Greenberg; James D Weiland Journal: Invest Ophthalmol Vis Sci Date: 2012-01-20 Impact factor: 4.799
Authors: John Xie; Gene-Jack Wang; Lindy Yow; Mark S Humayun; James D Weiland; Carlos J Cela; Hossein Jadvar; Gianluca Lazzi; Elona Dhrami-Gavazi; Stephen H Tsang Journal: Exp Eye Res Date: 2012-05 Impact factor: 3.467