INDOCYANINE GREEN ANGIOGRAPHY OF RETROBULBAR VASCULAR STRUCTURES IN SEVERE MYOPIA

PURPOSE: To evaluate angiographic findings of retrobulbar arteries and veins in severely myopic patients. METHODS: We examined 416 severely myopic eyes (213 patients) with refractive errors greater than -8.25 d iopters using indocyanine green videoangiography. A control group of 7 4 eyes (37 patients) had refractive errors within piano +/-3 diopters, Four severely myopic patients underwent computed tomographic angiogra phy to identify the entire intraorbital course of retrobulbar veins. R ESULTS: Of 416 severely myopic eyes, 231 (55.5%) exhibited retrobulbar arteries, which were tortuous and pulsatile behind the posterior pole of the globe. Retrobulbar arteries connected directly with choroidal arteries temporal to the macular area. In 17 of these 231 eyes, retrob ulbar arteries were also observed nasal to the optic nerve head, conti nuous with the Zinn-Haller ring around the optic nerve head and direct ly connected with choroidal arteries. In 39 severely myopic eyes (31 p atients), indocyanine green angiography disclosed retrobulbar veins, m ost of which coursed vertically just behind the posterior pole of the globe. These retrobulbar veins originated as an inferior vascular netw ork of the inferior orbital vein and drained into the superior orbital vein in the upper orbit. CONCLUSION: Retrobulbar arteries observed in this study were temporal and nasal short posterior ciliary arteries. Only the lateral collateral vein, which was one of the collateral chan nels between the superior and inferior orbital veins, was visible in s everely myopic eyes. Indocyanine green angiography is useful in evalua ting retrobulbar vascular structure in severely myopic eyes.