未熟児網膜症瘢痕期における中心網膜感度の検討

未熟児網膜症活動3期を経て現在, 視力良好, 両眼中心固視の25例50眼を対象にオクトパス自動視野計, 中心30度内城値測定プログラム (プログラム31) および, ゴールドマン動的視野検査を施行, 光凝固治療が未熟児網膜症発症眼の中心網膜発達に与える影響を検討した。対象を3群に分け (自然治癒27眼, 網膜耳側半周光凝固施行12眼, 網膜全周光凝固11眼), 網膜感度測定結果の評価方法としては, 31ある測定点を視神経線維の走行を考慮し, 黄斑部領域からの線維が分布する領域と網膜周辺部からの線維が分布する領域の2領域, および, 神経線維の走行を考慮せずに固視点を含む中央部とこれより耳側および鼻側の3領域をそれぞれ設定し, 両設定下, 各領域の平均感度を算出, 群間で比較した。結果は3群共にほぼ全例, 全領域において平均感度の低下がみられ, 特に全周光凝固群では他の2群に比して有意に低値を示した。また, 耳側半周のみ光凝固群において耳側領域と鼻側領域で平均感度に差がみられず, 中心網膜感度の低下は網膜上の光凝固部位と関係なく発現していた。さらに, 動的視野検査に基づいて定量化された網膜耳側周辺の搬痕化に伴う視野障害程度と, これに隣接する中心30度内の耳側感度の低下に相関性はなく, 光凝固施行群における中心網膜感度の低下が光凝固からの直接の影響以上に, 網膜症の重症度に相応した発達網膜自体の未熟性により強く起因していることが示唆された。 / Fifty eyes of 25 patients with good visual outcome and bilateral central fixation following regression of retinopathy of prematurity (ROP) from active stage 3 underwent the Goldmann kinetic perimetry and 30°central screening Octopus automated perimetry to study the effect of laser photocoagulation on the central retinal development. The eyes were divided into 3 groups; the first group had spontaneous regression (27 eyes), the second underwent temporal half-retinal photocoagulation (12 eyes) and the third received complete peripheral circumferential retinal photocoagulation (11 eyes). The results of retinal sensitivity measurement were assessed by dividing the 31 test points into 2 zones in alignment with the distribution of macular and peripheral retinal nerve fibers. The test points were also devided into 3 zones of the central zone including fixation points, the nasal and the temporal zones regardless of the distribution of the nerve fibers. The mean value of retinal sensitivity in all zones was calculated and compared among the groups. The mean retinal sensitivity was decreased in all fields of the 3 groups as compared with the normal control. Especially, the retinal sensitivity in patients who received complete peripheral circumferential retinal photocoagulation was lower than those inthe other 2 groups. In addition, temporal and nasal retinal sensitivities did not differ in patients who received retinal photocoagulation at the temporal half, suggesting the decrease in central retinal sensitivity did not attribute to the retinal position of the laser photocoagulation. Moreover, there was no correlation between the visual field disturbance resulting from temporal retinal scarring as evaluated by kinetic perimetry and the corresponding temporal peripheral areas in the 30°central screening. These findings suggest that the decrease in central retinal sensitivity in patients who underwent laser photocoagulation depended upon the severity of ROP and its poorly developed retinal immaturity rather than a direct effect of laser photocoagulation itself.