側副血行路の形成を認めた網膜動脈分枝閉塞症

Collateral vessels in a case with branch retinal artery occlusions

　57歳の男性の左眼に再発した閃輝性栓子による網膜動脈分枝閉塞症において，それぞれ別個に形成された側副血行路について報告し，これまでに報告された網膜動脈（分枝）閉塞症後の側副血行路の形成例についても検討を加えた．

　網膜動脈（分枝）閉塞症後の側副血行路には従来，網膜血管系と脈絡膜血管系を結ぶものと網膜血管系内で形成されるものとの2つの様式が知られていたが，自験例より網膜血管系内の側副血行路は，さらに同一網膜動脈分枝内で形成される順行性のもの，および隣接した動脈分枝との間に形成されるものとの2つの様式に細分できることを示した．そして，側副血行路の形成については，閉塞部位の中枢側と末梢側における網膜還流圧差が大きな要因となり得るものと考えた．

A 57-year-old male developed two episodes of branch retinal artery occlusion in his left eye 22 months apart. When seen on the next day after the first episode of occlusion of inferior temporal artery, a Hollenhorst plaque was located at the site of occlusion. The occluded site was bridged by collateral vessels. At the second episode, a bright plaque was located at the site of origin of the superior temporal artery. Arterial blood inflow wasmaintained through collateral vessels from the superior nasal artery and from the macular artery which appeared to be cilio-retinal in nature.

The present case thus revealed two types of collateral vessels : one bypassing the embolus in the artery and the other linking the occluded artery with the adjacent intact one. We assume that collat-eral vessels developed consequent to altered pres-sure gradient arounded the occluded vessels rather than to the altered metabolic demand in the infarct-ed retina.

Rinsho Ganka (Jpn J Clin Ophthalmol) 42(8) : 985-989, 1988