Argon Laser Treatment of von Hippel-Lindau Retinal Angiomas: II. Histopathology of Treated Lesions

Five angiomas from a case of von Hippel-Lindau angiomatosis were studied histopathologically 16 months following argon laser photocoagulation. Histopathologic examination of a moderately large angioma (one disc diameter [dd] in size) revealed that tissue destruction was only superficial, and that viable tumor elements remained in spite of a direct treatment on the lesion itself and two treatments on its arteriolar feeder vessel. Therefore, despite the use of laser photocoagulation and despite fluorescein angiography that showed interruption of flow through the tumor, complete destruction of this angioma had not occurred. Another angioma (0.8 dd in size) was also incompletely destroyed. Histopathological analysis confirmed, however, that very small angiomata are effectively obliterated following direct argon laser photocoagulation. The argon laser is also capable of focally occluding small and medium-sized feeder arterioles if sufficient energy is applied.