糖尿病性網膜症に対するクリプトンとアルゴンレーザー光凝固の比較

Comparison of krypton and argon laser photocoagulation in diabetic retinopathy

　糖尿病性網膜症光凝固例489眼にレーザー光凝固治療を行い，赤色クリプトンレーザー例171眼と青緑色アルゴンレーザー例318眼について，平均8.5カ月の経過と治療成績を比較した．

　糖尿病性網膜症の治療上，赤色クリプトンレーザーは従来の青緑色アンゴンレーザーと少なくとも同等の臨床効果を有し，術後の後部硝子体剥離化が少なく，硝子体牽引性障害の発生が低率であった．光凝固後の眼内臨床像の改善例はクリプトン群では77％，アルゴン群では76％であり，悪化例はクリプトン群15％，アルゴン16％で，ともにほとんど同率であった．光凝固後の矯正視力は，両群とも類似の分布を示した．両群とも，術中術直後の特記すべき合併症は生じなかった．

　光凝固前に後部硝子体の剥離がなかった例（クリプトン群，アルゴン群ともに107眼）で光凝固後に不完全あるいは完全に硝子体が剥離した頻度は，クリプトン群では19％で，アルゴン群の53％より有意に低率であった．これに関して，光凝固後に新たに発生した硝子体牽引性出血例は，クリプトン群では11％でアルゴン群の19％より少なかった．また，光凝固前にすでにあった硝子体出血が光凝固後に持続・増強したものは，クリプトン群で23％，アルゴン群で31％あった．牽引性網膜剥離もクリプトン群の方が少ない傾向を示した．

　以上から，赤色クリプトンレーザー光凝固は，特に眼底の汎網膜光凝固には有用な方法であるといえる．

We evaluated a series of 489 eyes with diabetic retinopathy treated either with red krypton or blue-green argon laser photocoagulation. The observa-tion period ranged from 3 to 18 months, average 8.5 months, following photocoagulation. A total of 171 eyes were treated by krypton and 318 eyes by argon laser.

Ocular findings improved in 131 eyes (77%) treated by krypton and 241 eyes (76%) by argon. The therapeutic effects were thus essentially similar for krypton and argon.

Traction-induced vitreous hemorrhage was a major complication of laser treatment in the present series. Excluding eyes in which vitreous hemorrhage was already present at the time of photocoagulation, it developed in 13 out of 123 eyes (11%) treated by krypton and in 51 out of 273 eyes (19%) treated by argon. In eyes in which vitreous hemorrhage was already present, vitreous hemorrhage increased in 11 out of 48 eyes (23%) treated by krypton and in 14 out of 45 eyes (31%) treated by argon. In eyes in which the posterior vitreous was still attached to the retina, vitreous detachment developed in 20 out of 107 eyes (19%) treated by krypton and in 57 out of 107 eyes (53%) treated by argon.

These findings indicate that krypton laser is ef-fective for diabetic retinopathy similar to argon laser. As major characteristic features, krypton in-duced significantly lesser incidence of traction-induced vitreoretinal complications than argon, in-cluding severe vitreoretinal hemorrhages and trac-tional retinal detachment.