未熟児網膜症に対する光凝固治療後の屈折諸要素

Refractive components in eyes with cicatricial retinopathy of prematurity after photocoagulation

　光凝固治療後の瘢痕期未熟児網膜症の屈折諸要素について検討した。光凝固により瘢痕期2度中等度で治癒した症例（瘢痕期2度中等度PHC，以下同）および瘢痕期2度強度PHCでは瘢痕期1度PHCおよび2度弱度PHCに比して，また全周光凝固施行例は光凝固2／3周以内の例に比して，有意に前房深度が浅く，水晶体厚径が大きく，水晶体厚径眼軸長比が大きく，角膜屈折力が大きいという結果を得た。2度中等度および強度PHCや全周光凝固例では近視，乱視が強くなり，近視の原因としては水晶体厚径の増加が，乱視の原因としては眼球の成長にともなう角膜乱視が重要視された。全周光凝固例の在胎週数は2／3周以内の光凝固例に比して有意に小さく，このような眼球の未熟性が屈折諸要素に影響している可能性もあり，光凝固自体の屈折諸要素に及ぼす影響については今回の結果だけでは判断できない。

As a part long-term study on the effect ofphotocoagulation (PHC) on retinopathy ofprematurity (ROP), we evaluated 99 eyes, 51patients, regarding the refractive components ofthe eyes in cicatricial phase of ROP. The agesranged from 11 to 21 years, average 14.9 years. Theretinopathy was graded according to the Japaneseclassification. Grade 1 PHC : artificial PHC scaronly. Mild grade 2 PHC : dragged disc, normalmacula with peripheral PHC scar. Moderate tosevere grade 2 PHC : dragged disc, distortion orectopia of macula with peripheral PHC scar.Patients with grade 3 PHC showing retinal detach-ment or more advanced cicatrization were exclud-ed from the study.

Eyes with moderate or severe grade 2 PHCshowed shallower anterior chamber, greater lensthickness, greater corneal refractive power andgreater ratio of lens thickness to the axial lengththan eyes with grade 1 PHC or mild grade 2 PHC.

In eyes with grade 1 PHC and mild grade 2 PHC, prior full-circumferential PHC resulted in shal-lower anterior chamber, greater lens thickness,greater corneal refractive power and greater ratioof lens thickness to the axial length than segmentalPHC.

Eyes with grade 2 PHC and those with full-cir-cumferential PHC showed a higher incidence and agreater degree of refractive errors.

Above findings seemed to suggest that eyes withsevere progressive “plus” disease should be treatedby photocoagulation or cryotherapy to preventdevelopment of ROP into cicatricial stage of grade2 PHC.