Transpupillary thermotherapy: new observations on neuroprotection of retinal ganglion cells.

ranspupillary thermotherapy (TTT) is a technique in which heat s delivered to the posterior segment of the eye through the pupil sing a modified low power diode laser with a broad beam. This ethod uses infrared radiation to increase the temperature in the reated tissue up to 10 ◦C above baseline levels and it is been tried or the treatment of various intraocular tumors and choroidal neoascularization in age-related macular degeneration [7]. However, he bulk of clinical data regarding TTT yields mixed results and furher studies are need to demonstrate that improvements in health utcomes occur with acceptable levels of adverse effects. Recently several neuroscientists using the visual system as a odel to study degenerative disorders in the central nervous sysem (CNS) have turned their attention to the potential possibilities f this technique to treat some retinal neurodegenerative diseases. n CNS it is well establish that in response to physiological, pathoogical or environmental stress, neurons and glial cells activate the eat shock response inwhich a set of heat shock proteins (HSPs) are nduced, playing important roles in cellular repair and protective echanisms [1]. It is though that an increase in protein damage an trigger this response, and available studies suggest that HSPs re important in the refolding of partially denatured proteins, the revention of protein aggregation, the reduction of inflammatory esponses and the inhibition of cell death pathways [1–3,6]. These bservations point out to HSPs as multifaceted proteins that proect injured neurons from severe damage and allow resumption of ormal cellular and physiological activities through a wide variety f mechanisms.