Replacement therapy of stem cells transplantation represents a potential treatment for neural retinal diseases. Despite the encouraging results in laboratory, the clinical application of cells replacement therapy is still difficult because the limitation of seed cells, immunologic rejection, oncogenicity and ethical problems, etc. Recent breakthrough in somatic reprogramming provides a promising solution overcoming these obstacles. Further researches on virus free reprogramming will make the clinical application of stem cell replacement therapy possible.
Objective To detect the apoptosis of vascular endothelial cells and retinal pigment epithelial (RPE) cells in vitro induced by verteporfin-photodynamic therapy. Methods Cultured vascular endothelial cells and human RPE cells were incubated with verteporfin at a concentration of 1.0 mu;g/ml which was equivalent to the initial plasma level of verteporfin in clinical therapy. Each kind of cells were divided into 6 groups according to different time of incubation: 0, 5, 15, 30, 60, and 120 minutes group. After incubated, the cells were illuminated by the laser light with the maximum wavelength of absorption of verteporfin (wavelength: 689 nm, power density: 600 mW/cm2) with the power of 2.4 J/cm 2for 83 seconds. The percentage of cellular apoptosis was measured by flow cytometry 3 hours after PDT, and the measurement was repeated thrice. Results The proportion of cellular apoptosis 3 hours after PDT were 0.01plusmn;0.01, 0.25plusmn;0.02, 0.32plusmn;0.02, 0.41plusmn;0.04, 0.49plusmn;0.03 and 0.61plusmn;0.02, respectively in 0-120 minutes group of vascular endothelial cells; and 0.02plusmn;0.01, 0.22plusmn;0.01, 0.31plusmn;0.02, 0.38plusmn;0.03, 0.47plusmn;0.05 and 0.58plusmn;0.03 respectively in 0-120 minutes group of RPE cells. The proportion of cellular apoptosis of both kinds of the cells increased as the incubation time was prolonged. There was no significant difference of the percentage of cellular apoptosis between the accordant time groups in the two kinds of cells (P＞0.05). Conclusions Cellular apoptosis can be quickly induced by verteporfin-PDT both in human vascular endothelial cells and RPE cells; under the same condition in vitro, PDT has no obvious selection for the apoptosis of the two kinds of cells. (Chin J Ocul Fundus Dis, 2006, 22: 253-255)
Purpose To evaluate the correlation of retinal thickness between optical coherence tomography (OCT) images and histologic slides ． Methods Retinal thickness was measured in 16 rabbit retinal histologic slides．The same eyes were previously viewed by OCT for the comparison of results between two methods．Retinal thickness of each OCT image section was measured using both the manually assisted (requiring observer localization of reflectivity peaks) and the automated modes of the computer software． Results Retinal thickness as measured by OCT demonstrated a high degree of correlation with retinal histologic study．The automate d method (gamma;=0．66，P＜0.01) was less reliable than the manually assisted one (gamma;=0．84，P＜0．001)．The former had an error in 95% confidence interval，ranged in-0.71～11.09 mu;m，the latter had a less error，ranged in-2.99～5.13mu;ｍ． Conclusion Retinal thickness can be quantitatively measured by OCT examination．However，computer automatic identification of the reflective boundaries may result in errors in some cases．To measured the retinal thickness by manually assisted mode can increase the degree of accuracy． (Chin J Ocul Fundus Dis，2000，16：71-138)