Absorption of diode 810 nm used for transpupillary thermotherapy by blood. An in vitro study.
OBJECTIVE
To evaluate the in vitro energy attenuation by transpupillary thermotherapy (TTT) using an 810-nm diode laser after the treatment of exudative age-related macular degeneration.


METHODS
In this experiment, an 810-nm diode laser was coupled to a slit lamp to deliver laser energy to a laser-power sensor adjusted in the track of the laser light. The spotlight was 0.5 mm in diameter; duration of exposure, 3 seconds. Citrated Pasteur pipettes were filled with blood diluted in saline in several concentrations and placed in the path of the laser light. The absorption of the light measured by the power sensor was tested for various delivered irradiances between 50.92 and 509.29 W/cm2. The differences were analyzed statistically.


RESULTS
There were significant differences in laser blockage comparing various conditions for all power levels (P<0.05). Increasing the proportion of blood resulted in more laser blockage with all irradiances (P<0.05).


CONCLUSIONS
Blood significantly blocks the transmission of the 810-nm diode TTT laser.
Morales
Ana Muñoz
AM
Department of Ophthalmology, Virgen del Rocío Hospital, Seville, Spain.
Lapuente
Carlos Ruiz
CR
Peyman
Gholam A
GA
Kivilcim
Muhamet
M
D001769:Blood; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods*; D053685:Laser Therapy; D008268:Macular Degeneration / Q000628:therapy*; D011680:Pupil