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Ocular heat flow associated with threshold in vivo exposure to 1090 nm infrared radiation for cataract induction
Author(s) -
YU Z,
SCHULMEISTER K,
TALEBIZADEH N,
KRONSCHLÄGER M,
SÖDERBERG P
Publication year - 2014
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2014.s080.x
Subject(s) - sclera , optic nerve , ophthalmology , medicine , thermocouple , lens (geology) , pupil , materials science , optics , physics , composite material
Purpose To investigate the heat flow in the ocular media after in vivo exposure to 1090 nm IRR at the radiant exposure intended for cataract induction. Methods Six‐weeks‐old albino SD rats were anesthetized and pupil‐dilated prior to exposure. The animals were divided into two groups of 12. All animals were unilaterally exposed to 197 W/cm2 IRR at 1090 nm within the dilated pupil for 8 s. In one group, temperature was recorded with the thermocouples placed at the limbus, in the vitreous behind lens and on the sclera next to the optic nerve, respectively in the exposed eye. In the other group, one thermocouple was placed at the limbus and another on the sclera next to the optic nerve in the exposed eye. Temperature was recorded from the end of the exposure till temperature back to the baseline. Results In the first group, the induced temperature rise was, 95% CI, 11±3 ºC at the limbus, 16±6 ºC in the vitreous behind lens and 16±7 ºC on the sclera next to the optic nerve in the exposed eye. The rate constant was 2.4±0.4×10‐2 s‐1 at the limbus, 2.6±0.3×10‐2 s‐1 in the vitreous behind lens, and 2.9±0.6×10‐2 s‐1 on the sclera next to the optic nerve in the exposed eye (d.f. = 11). In the second group, the temperature rise was 9±1 ºC at the limbus and 26±10 ºC on the sclera next to the optic nerve in the exposed eye. The rate constant was 2.4±0.3×10‐2 s‐1 at the limbus and 4.3±1.1×10‐2 s‐1 on the sclera next to the optic nerve in the exposed eye (d.f.=11). Conclusion An exposure to 197 W/cm2 1090 nm IRR for 8 s induces a temperature increase of 10 ºC at the limbus and 25 ºC close to the retina. The temperature fall in the anterior ocular segment is twice rapid in the posterior segment of the eye.