Azzolini C, Fantaguzzi S, Brancato R, Docchio F, Bandello F, Guarisco L
Department of Ophthalmology and Visual Sciences, University of Milan, Italy.
Graefes Arch Clin Exp Ophthalmol. 1996 Aug;234(8):488-92. doi: 10.1007/BF00184856.
Sodium fluorescein staining of the vitreous following fluorescein angiography may interact with laser photocoagulation.
We evaluated the laser absorption by fluorescein in the vitreous when photocoagulation is performed following fluorescein angiography in 15 eyes of nine diabetic patients. Axial fluorescein concentration in the vitreous was measured by a scanning vitreal fluorophotometer. The amount of light absorbed by the fluorescein within the vitreous was calculated according to the Lambert-Beer law.
The mean fluorescein concentration ranged from 2.93 ng cm-3 to 105.16 ng cm-3 at 1 h after injection of fluorescein and from 8.03 to 188.56 ng cm-3 after 4 h. Maximum laser absorption at 488 nm ranged from 6.79% (after 1 h) to 14.53% (after 4 h); at 514.5 nm it ranged from 0.96% to 2.14%; at 532 nm it ranged from 0.03% to 0.07%. At lambda > 550 nm, laser absorption was found to be negligible.
In order to optimize the effect of photocoagulation, especially during long photocoagulation sessions, argon blue laser (488 nm) should be avoided following fluorescein angiography. Argon green laser (514.5 nm) should be used within 1 h after fluorescein injection. Frequency-doubled Nd:YAG laser (532 nm), krypton laser (647 nm) or semiconductor diode laser (810 nm) may be used at any time.
荧光素血管造影术后玻璃体的荧光素钠染色可能与激光光凝相互作用。
我们评估了9例糖尿病患者15只眼中荧光素血管造影术后进行光凝时玻璃体中荧光素的激光吸收情况。通过扫描玻璃体荧光光度计测量玻璃体中的轴向荧光素浓度。根据朗伯-比尔定律计算玻璃体中荧光素吸收的光量。
荧光素注射后1小时，荧光素平均浓度范围为2.93 ng/cm³至105.16 ng/cm³，4小时后为8.03至188.56 ng/cm³。488 nm处的最大激光吸收范围为6.79%（1小时后）至14.53%（4小时后）；514.5 nm处为0.96%至2.14%；532 nm处为0.03%至0.07%。在波长>550 nm时，发现激光吸收可忽略不计。
为了优化光凝效果，尤其是在长时间光凝过程中，荧光素血管造影术后应避免使用氩蓝激光（488 nm）。荧光素注射后1小时内应使用氩绿激光（514.5 nm）。倍频Nd:YAG激光（532 nm）、氪激光（647 nm）或半导体二极管激光（810 nm）可在任何时间使用。
