緑内障性網膜神経線維束萎縮と乳頭陥凹の相関の検討

Correlation between retinal nerve fiber bundle atrophy and optic disc cupping

　緑内障眼における網膜神経線維束萎縮（NFA）所見，乳頭陥凹，網膜機能の相関について検討した．対象は初期から中期緑内障21症例29眼である．乳頭を12のセクターに分割し，耳上側，耳下側の四つの神経線維束分布域をF₁，F₂領域とし，各部位のrimに対する面積率（Rim A）を測定した．また，オクトパス自動視野計の測定結果に基づく0°〜60°内のF₁，F₂神経線維束分布内の網膜感度をさらに乳頭近位から遠位の三つのサブセクターに分割し，各部位での感度の定量化（％S）を行った．乳頭近位側の％SとRim Aほど強い相関関係がみられ，近位側の機能低下ほど乳頭陥凹におよぼす影響が大きかった．

　NFA所見を乳頭より離れて見られる遠位萎縮型，乳頭に近接する近位萎縮型および全体萎縮型に分類し，さらに程度により（⧺），（＋）に分類した．遠位萎縮型は遠位側機能低下優位，近位萎縮型（⧺）は近位側機能低下優位であった．三者の相関の検討により，NFA所見に伴う機能変化がかなり正確に予想できると考えられる．

A total of 29 eyes with early and middle glaucomatous field defects were evaluated as to the correlation among disc cupping, retinal nerve fiber bundle atrophy and visual field sensitivities.

Rim/disc ratios were calculated along superior and inferior temporal disc margins each (F₁ & F₂). The sensitivities along the nerve fiber bundle corresponding to F₁ and F₂ were determined by automatic perimeter (Octopus). Each arcuate area was subdivided into three, proximal, middistal and distal, portions in rela-tion to the distance from the disc margin.

The visual field sensitivities in the proximal portion was closely correlated with the rim/disc ratio in thecorresponding sector and with the enlargement of glaucomatous cupping in general.

Objective evaluation of retinal nerve fiber bundle atrophy (NFA) was made on red-free fundus photo-graph. NFA was expressed as proximal, distal or total atrophy type. Proximal and distal visual field damage was prone to be associated with proximal and distal NFA type respectively.

The findings indicates that the visual field damage in glaucoma can be estimated from the funduscopic appearance of NFA.

Rinsho Ganka (Jpn J Clin Ophthalmol) 40(7) : 725-729,1986