Effect of low fluence diode laser irradiation on the hydraulic conductivity of perfused trabecular meshwork endothelial cell monolayers.
OBJECTIVE
To determine the effect of low-fluence diode laser irradiation upon the fluid perfusion characteristics of cultured human trabecular meshwork cell monolayers when placed in a specially designed testing apparatus and subjected to fluid flow driven by a hydrostatic pressure gradient.


METHODS
Two experimental series were conducted. In the first series, six low-fluence diode laser irradiation experiments were conducted using cultured human trabecular meshwork cell monolayers grown on filter supports. Upon reaching a steady state perfusion condition at approximately 5.0 mmHg, monolayers were irradiated at fluencies ranging from 0.2619 to 0.8571 J/cm2 using a diode laser (lambda=810 nm). Perfusion and data collection continued for 45 minutes post-irradiation, after which the monolayers were tested to determine post-experimental viability. Hydraulic conductivity values were analyzed for post-irradiation response in 2.5-minute intervals, grouped by viability. In the second series, a total of six irradiated experiments and six simultaneous nonirradiated control experiments were conducted. Fluence values of 0.3571 J/cm2 (n=3) and 0.4286 J/cm2 (n=3) were used. Hydraulic conductivity values were analyzed for post-irradiation response in 2.5-minute intervals, grouped by irradiated vs. nonirradiated control groups.


RESULTS
In the first series, analysis showed that the viable monolayers exhibited a statistically significant increase in hydraulic conductivity (p<0.001) from 10 minutes post-irradiation onward. The non-viable monolayers exhibited a statistically significant decrease in hydraulic conductivity. In the second series, irradiated groups showed a significant difference (p<0.001) from nonirradiated controls from 10 minutes post-irradiation onward.


CONCLUSIONS
Low-fluence diode laser irradiation increases hydraulic conductivity in viable perfused TM cell monolayers when compared to baseline values or simultaneous nonirradiated controls while decreasing hydraulic conductivity in nonviable monolayers.
Roberts
Cynthia J
CJ
Department of Ophthalmology, The Ohio State University, Columbus 43210, USA. roberts.8@osu.edu
Rivera
Brian K
BK
Grzybowski
Deborah M
DM
Mahmoud
Ashraf M
AM
Weber
Paul A
PA
D001082:Aqueous Humor / Q000378:metabolism*; D001692:Biological Transport; D018938:Caco-2 Cells; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003907:Dexamethasone / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D005136:Eye Proteins / Q000378:metabolism; D005938:Glucocorticoids / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D006874:Hydrostatic Pressure; D028022:Low-Level Light Therapy; D008565:Membrane Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D014129:Trabecular Meshwork / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D062826:Zonula Occludens-1 Protein; D000099179:Myocilin
D003598:Cytoskeletal Proteins; D003907:Dexamethasone; D005136:Eye Proteins; D005938:Glucocorticoids; D006023:Glycoproteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D062826:Zonula Occludens-1 Protein; D000099179:Myocilin; C569042:TJP1 protein, human