恢復期Ethambutol視神經病變的視覺功能研究

Visual Function in Recovered Ethambutol Optic Neuropathy

翁林仲(Lin-Chung Woung) ； 周介仁(Jien-Ren Jou) ； 廖述朗(Shuh-Lang Liaw) ； 藍偉倫(Wei-Lun Lan) ； 羅崇源(Chung-Yuan Lo) ； 凌瑞中(Jui-Chung Lin)

《中華民國眼科醫學會雜誌》 33卷1期 (1994/03) Pp. 47-53

https://doi.org/10.30048/ACTASOS.199403.0008

摘要

Ethambutol hydrochloride是治療結核病菌極為有效的口服藥。在治療的病人中，大約有0.5到1.5%會發生Ethambutol毒性視神經病變。
本報告研究自79年1月至82年12月間，Ethambutol視神經病變病患36人，平均年齡56.3歲。病患接受Ethambutol治療劑量為每天每公斤15至25毫克間。
36名病患中，選取患病初期視力小於0.5，停藥後追踪時期視力恢復至1.0至Axial type病患15名（29眼），研究其視覺功能的恢愎情形。
結果顯示：恢復期之視覺誘發電位34.5%(10/29)患眼殘餘有振幅降低、潛時(P100)延長現象，或僅殘餘潛時延長現象（四眼）；48.3%(14/29)患眼殘餘有Deuteran或Tritan型色覺不正常；51.7%(15/29)患眼殘餘紅色光中心閃爍融合頻率值(CFF)不正常；58.6%(17/29)患眼殘餘有中心旁視野缺損；62.1%(18/29)患眼殘餘低度及中度Spatial frequency的對比敏感度異常；而高達72.4%(21/29)患眼仍殘餘瞳孔反應週期(PCT)的異常延長現象。
Ethambutol視神經病變的恢復期視覺功能表現究竟如何，目前尚未有完整報告；本篇研究結果顯示：雖然視力已恢復至正常的1.0，但是其他視覺功能的恢復仍然是不完全的(incomplete recovery)；而且，本研究顯示，Ethambutol視神經病變同時影響神經節細胞中的P細胞和M細胞系統。

並列摘要

The visual acuity of the ethambutol optic neuropathy will recover within 3 to 4 months usually after discontinuing the drug. We want to declare the extent of the recovery of other visual functions.
Thirty six axial type ethambutol optic neuropathy patients who visited our neuro-ophthalmology clinic from Jan. 1990 to Dec. 1993 were included in this study. 15 patients (29 eyes) got a recovery of visual acuity better than 1.0. The average follow up time after the recovery is 21.7 months. Pattern reversal VEP, Farnsworth-Munsell 100-Hue color vision test, Critical flicker frequency (CFF), Goldmann perimetry, contrast sensitivity by MCT 8000 and edge-light pupil cycle time were performed for each eye.
Latency (P100) of visual evoked potential was delayed in 34.5% (10/29) of eyes. In color vision, 48.3% (14/29) of eyes have deuteran or tritan defect. 51.7% (15/29) eyes revealed abnormality of red CFF with value lower than 31 Hz. In visual field, 58.6% (17/29) of eyes have paracentral scotoma or arcuate scotoma. Contrast sensitivity was depressed in 62.1% (18/29) of eyes mainly at middle and low spatial frequency. Pupil cycle time was prolonged in 72.4% (21/29) of eyes.
Except visual acuity, other visual functions of the recovered ethambutol optic neuropathy patients were incomplete. The extent of recovery of the visual function is as followed: visual acuity-VEPs-color sense-CFF-visual field-contrast sensitivity-pupil cycle time.

並列關鍵字

Ethambutol optic neuropathy ； Visual evoked potential ； Color vision ； Critical flicker frequency ； Visual field ； Contrast Sensitivity ； Pupil cycle time