Purchase this article with an account.
M Krause, J Xiong, ES Gragoudas, LH Y Young; Treatment of Experimental Choroidal Melanoma with a Nd:YLF Laser at 1047 nm . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1152.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Pigmented choroidal melanoma was treated with a new near infrared laser. Methods: B16F10 melanomas were grown in the subchoroidal space of 64 rabbits (tumor height 2.0 - 4.0 mm). Laser radiation from a Neodymium:Yttrium-Lanthanum-Fluoride laser (1047 nm) was delivered to the retina as a rapidly - scanned transpupillary beam. To investigate melanin heating, treatment with focused light (beam waist = 25 m, irradiance = 100 kW / cm2) was compared with collimated light (beam waist = 2 mm, irradiance = 16 W / cm2) at the same wavelength. Fine wire thermocouples were implanted at the base of 3 tumors for in vivo temperature measurements. Additional animals were left untreated or used for histopathology. Results: Twenty-seven animals received a single treatment with 1047 nm focused light. The rate of complete tumor eradication was 91% (10 / 11 animals) at a dose of 125 J / cm2 and 75% (9 / 12 animals) at 87 - 63 J / cm2. The eradication rate decreased to 25% in average (1 / 4 animals) at 38 J / cm2 and below (p < 0.001). Continuous tumor growth was observed in animals treated with collimated radiation and in untreated controls. Temperature measurements indicated rapid tissue heating of the tumor base at 1047 nm; control studies using 805 nm light did not exhibit such heating. Conclusions: A single treatment with a rapidly - scanned, tightly - focused near infrared laser beam yields consistent instantaneous tumor eradication for light doses of 63 J / cm2 or greater. Use of treatment beams with larger beam waists did not show significant response. Focused irradiation at this wavelength may provide more effective sub-millisecond heating of melanin than collimated irradiation, resulting in immediate photothermal disruption of tumor cells.
This PDF is available to Subscribers Only