増殖糖尿病網膜症に対する小切開硝子体手術の視力予後因子の検討

Prognostic factors for visual outcome following microincision vitrectomy for proliferative diabetic retinopathy

要約　目的：増殖糖尿病網膜症（PDR）に対する小切開硝子体手術の視力予後に関する因子の報告。

対象と方法：増殖糖尿病網膜症に対し，過去8年6か月間に初回小切開硝子体手術を行い，6か月以上の経過が追えた220眼を対象とした。単純硝子体出血155眼，黄斑外網膜剝離43眼，黄斑部網膜剝離22眼であり，視力が改善した183眼と不変または悪化した37眼について，周術期因子との関係を解析した。

結果：単純硝子体出血群では，他の2群よりも高年齢で，後部硝子体剝離形成と汎網膜光凝固の頻度が高く，増殖膜の頻度が低かった。視力改善群は，視力が不変または悪化した群よりも，術前の矯正視力が不良で，硝子体出血と後部硝子体剝離の頻度が高く，増殖膜の頻度が低かった。多変量解析による検討では，術前に増殖膜がないことが術後の視力改善と有意に関連していた（p＝0.02）。

結論：PDRに対する小切開硝子体手術では，手術時の増殖膜の有無が視力予後に関係する。

Abstract　Purpose：To report prognostic factors for visual outcome following microincision vitrectomy for proliferative diabetic retinopathy.

Case and Method：This retrospective study was made on 220 eyes that received microincision vitrectomy as initial surgery for proliferative diabetic retinopathy. The series comprised 155 eyes with simple vitreous hemorrhage, 43 eyes with macula-on retinal detachment, and 22 eyes with macula-on retinal detachment. After surgery, visual acuity improved in 183 eyes and remained unchanged or deteriorated in 37 eyes. These two groups were evaluated regarding perioperative factors.

Results：Cases with simple vitreous hemorrhage were characterized by higher age, more frequent posterior vitreous detachment and history of panretinal photocoagulation, and lower incidence of proliferative membrane than the other two groups. Eyes that showed improved visual acuity after surgery were characterized by lower visual acuity, more frequent vitreous hemorrhage and posterior vitreous detachment, and lower incidence of proliferative membrane. Multivariant analysis showed significant association between visual outcome and absence of proliferative membrane before surgery（p＝0.02）.

Conclusion：Presence or absence of proliferative membrane was significantly related to visual outcome following microincision vitrectomy for proliferative diabetic retinopathy.