Diode laser-induced thermal damage evaluation on the retina with a liposome dye system
✍ Scribed by Desmettre, Thomas J.; Soulie-Begu, Sylvie; Devoisselle, Jean Marie; Mordon, Serge R.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 144 KB
- Volume
- 24
- Category
- Article
- ISSN
- 0196-8092
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✦ Synopsis
Background and Objectives:
The aim of the study was to evaluate the feasibility of retinal thermal damage assessment in a rabbit eye model by using laser-induced release of liposomeencapsulated dye. Study Design/Materials and Methods: After anesthesia, thermosensitive liposomes (DiStearoyl Phosphatidyl Choline: DSPC) loaded with 5,6-carboxyfluorescein were injected intravenously to pigmented rabbits. Retinal photocoagulations were performed with a 810nm diode laser (P=100-400 mW, л=500 m, 1s) (OcuLight, IRIS Medical Instruments, Mountain View, CA). Fluorescence measurements in the area of the laser exposures were then realized with a digitized angiograph (CF-60UVi, Canon-Europe, The Netherlands ; OcuLab, Life Science Resources, UK). Results: Fluorescent spots were observed for power ranging from 100 ± 5 mW to 400 ± 5 mW. The fluorescence intensity increased linearly with the power and reached a plateau at 280 ± 5 mW. The fluorescence intensity was correlated to the maximum temperature at the center of the laser spot with a linear increase from 42 ± 3°C to 65 ± 3°C. These results are in agreement with our two previous studies with DSPC liposomes for temperature measurements in a tissue model and then in a vascular model.
Conclusion:
This preliminary study demonstrates the possibility of a laser-induced release of liposome-encapsulated dye for a quantification of diode laser induced thermal damage in ophthalmology. Such a method could be useful for a real-time monitoring of laser photocoagulation for conditions such as choroidal neovascular membranes when a precise thermal damage is required near the foveolar area.