Fourteen eyes from ten donors of varying ages ranging from 29 to 80 years were used. years were used. Along a horizontal nasal to temporal meridian, there were differences in several cell shape and size characteristics. Generally, the cell area and shape was relatively constant and regular except in the much periphery. In the outer third of the retina, the cell area and shape differed from your inner two-thirds statistically significantly. In the macula and the much periphery, an overall decreasing pattern in RPE cell density, percent hexagonal cells, and form factor was observed with increasing age. We also found a pattern toward increasing cell area and eccentricity with age in the macula and the much periphery. When individuals were divided into two age groups, <60 years and 60 years, there was a higher cell density, lower cell area, lower eccentricity, and higher form factor in the younger group in the macula and the much periphery (p<0.05 for all those measurements). No statistically significant differences in RPE morphometry between age groups were found in the mid-periphery. Conclusions Human cadaver RPE cells differ mainly GBR 12935 in area and shape in the outer one third compared to the inner two-thirds of the temporal retina. RPE cells become less dense and larger, lose their common hexagonal shape, and become more oval with increasing age. Introduction The RPE is located in between the neurosensory retina and the choroid. The main functions of the RPE are to supply the highly metabolically active retina with nutrients and remove waste by-products from your photosensory processes of the cones and rods. The RPE plays a key role in the pathogenesis of age-related macular degeneration (AMD) [1,2]. The healthy structure of the RPE sheet has been described as a monolayer of homogeneous cells of hexagonal shape, forming a barrier between the neurosensory retina and the underlying choriocapillaris [3]. This honeycomb appearance of the RPE is GBR 12935 known to be the most stable configuration of cells of the same size in nature [4]. A hexagonal network of cells allows for the GBR 12935 greatest protection of area without cell overlap or vacant areas and with the least amount of surface tension [4]. Little is known about how the morphometry of RPE cells changes with location or normal aging. Understanding the normal aging process of RPE will help us better understand differences in age-related retinal pathology. Age-related loss of RPE cells has been reported in previous literature using numerous methods (Table 1). A prior study by Panda-Jonas et al. [5] reported a 0.3% decrease per year, and Del Priore et al. [6] found a 0.23% rate of decline per year. In contrast, other investigators, such as Watzke et al. [7] and Harman et al. [8], found no age-dependent changes in RPE cell density. Previous studies by Tso and Friedman [9], and Dorey et al. [10], which looked at different retinal regions, showed that RPE cell density in the macula decreases with age. Gao and Hollyfield [11] concluded that the RPE declines at a rate of 14 RPE cells/mm2 per year. Table 1 Summary of past studies. test. The curves on each panel of Physique 4 were created using the trendline tool in Excel and a second-order polynomial for regression. Each trendline was from all four subjects. One-way ANOVA and Tukey analysis were performed with GraphPad Prism (La Jolla, CA) version 6.1 software. Other analyses were conducted with SAS, version 9.4 (Cary, NC). Open in a separate window Physique 4 Location study. A: Cell density from your optic nerve head (ONH) to the much periphery. Cell density appeared to remain consistent until approximately 13 mm from your optic nerve (i.e., the much periphery). Cell density at the posterior pole was more than four occasions greater than at the much periphery. B: Cell area according to Edn1 distance from your ONH. The cell area appeared to remain consistent until approximately 15 mm from your optic nerve (i.e., the much periphery). The mean cell areas at the much periphery were almost four occasions value at the macula/posterior pole. C: Eccentricity varies according to distance from your optic nerve head. There was a clear trend for increasing eccentricity from your macula toward the much periphery..