後部硝子体剥離眼のvitreous fluorophotometry

Vitreous fluorophotometry in eyes with posterior vitreous detachment

　経年性後部硝子体剥離が，フルオレセイン-Naの硝子体内へのinwardおよびoutward transportにどのような影響を与えるかを知る目的で，vitreous fluorophotometryを行った．

　方法としてinward transportは，色素静注1時間値で，outward transportは，硝子体螢光濃度が最高値となった時点での血漿内freeフルオレセイン濃度と，硝子体螢光濃度の比（Cs／Cv）を指標として判定した．

（1）色素静注1時間後の後部硝子体および中部硝子体螢光濃度は，後部硝子体剥離眼において有意に高く，特に中部硝子体値で著明であった．螢光濃度の上昇は，血液-網膜関門の透過性亢進によるものではなく，液化硝子体によるフルオレセイン粒子の拡散速度の増大によるものと考えられた．一方，前部硝子体値は有意差はなかった．

（2） Outward transportの指標としてのCs／Cvは，有意差がみられなかった．

　硝子体性状はvitreous fluorophotometryの結果を判定する上で，常に考慮に入れねばならない問題と考えられた．

Using kinetic vitreous fluorophotometry, the permeability of the blood-vitreous barrier to fluores-cein passing in and out of the vitreous cavity was compared in eyes with and without posterior vitre-ous detachment.

Inward permeability was judged by vitreous fluo-rescein concentration at one hour after dye injec-tion. The ratio between outward and inward per-meability was calculated by the method described by Blair et al. Fluorescein concentration in the posterior and midvitreous was significantly higher in eye with posterior vitreous detachment than those without. There was no essential difference in the ratio between outward and inward permeability between both groups.

The present results indicated that the eyes withposterior vitreous detachment exhibited no essential impairment in barrier function. In these eyes, high concentration of fluorescein in the posterior and mid vitreous was considered to reflect the intravit-real diffusion of the dye.