網膜色素変性症における視野障害の進行

Progression of visual field defects in pigmentary retinal dystrophy

　定型網膜色素変性症における視野狭窄の進行様式を明らかにするためにゴールドマン視野のV-4イソプターでの平均視野境界（MB）を求め，経過観察年数毎の視野狭窄の進行状況を示した．

（1）明らかな視野の悪化例は10年以下の各経過年数においていずれも50％を越えず，本症における視野障害の進行速度は比較的緩慢であることがわかった．

（2）進行様式に関して，平均視野境界が50度より広い例では視野狭窄の進行は緩慢であるが，これが30度から50度の範囲にはいるようになると比較的急速に進行し，さらに30度未満になると視野狭窄の進行は再び緩慢となる傾向があることが示された．

　本症患者の指導にあたっては以上の事実を踏まえて適切な助言を与えることが望ましい．

We evaluated the mode of progression of visual field defects in 60 eyes in 33 cases with typical pigmentary retinal dystrophy over a period of 1 to 10 years. As parameter for the visual field, we used the mean boundary (MB) which was defined as the average of four points of V-4 isopter by Goldmann perimeter.

Some eyes showed an apparent increase of MB of less than 5 degrees, particularly within a priod of 3years or less. Such improvement was interpreted as technical variability of measurements, so that changes in MB of 5 degrees or less were discarded in the ensuing evaluation.

The percentage of eyes showing genuine progres-sive field defects increased along with the period of observation. In no instance, however, the amount of progression of field defects did not reach 50% dur-ing the period of maximally 10 years. As a general rule, visual fields with the MB lying between 30 and 50 degrees showed a more rapid progressive con-traction.

Rinsho Ganka (Jpn J Clin Ophthalmol) 41(5) : 473-476, 1987