Wilkinson Colleen H, van der Straaten David, Craig Jamie E, Coote Michael A, McCartney Paul J, Stankovich Jim, Stone Edwin M, Mackey David A
Center for Eye Research Australia, Department of Ophthalmology, University of Melbourne, Royal Victorian Eye and Ear Hospital, 32 Gisbourne Street, East Melbourne, Australia 3002.
J Glaucoma. 2003 Jun;12(3):237-42. doi: 10.1097/00061198-200306000-00010.
To demonstrate the effect in vivo of the myocilin gene mutation Thr377Met on outflow facility of aqueous humor, as measured by tonography.
Forty-two members of a pedigree known to carry the Thr377Met mutation were examined for glaucoma, evaluated with tonography, and screened for myocilin mutations. Tonography was used to calculate the coefficient of aqueous outflow facility (C), as well as the ratio of the resting intraocular pressure to C (P(0)/C). Subjects were reexamined for glaucoma 5 years after tonography.
Seven subjects were excluded because of previous treatment known to alter facility of aqueous outflow. The mean outflow facility of the eyes of the 12 subjects carrying the Thr377Met mutation was significantly reduced compared with the 23 non-carriers' eyes using both C (P<0.001) and P(0)/C (P<0.001). Reduced outflow facility was also demonstrated in those mutation carriers who were not yet expressing clinical signs of glaucoma or ocular hypertension when measured using C (P = 0.015) and P(0)/C (P = 0.001). After 5 years, progression towards glaucoma had occurred in 5 of the myocilin mutation-carriers, 2 of whom showed bilateral progression; 3 carriers remained completely normal. Four subjects had bilateral glaucoma at the outset and remained unchanged. The carriers' eyes that progressed towards glaucoma had reduced outflow facility compared with those that remained normal, although the difference was not statistically significant.
Carriers of the myocilin Thr377Met mutation have reduced outflow facility, which may be detected prior to developing glaucoma. Tonography was not seen to be clinically useful in predicting progression towards glaucoma.
通过眼压描记法来证明肌纤凝蛋白基因Thr377Met突变在体内对房水流出易度的影响。
对已知携带Thr377Met突变的一个家系中的42名成员进行青光眼检查，采用眼压描记法进行评估，并筛查肌纤凝蛋白突变。眼压描记法用于计算房水流出易度系数（C）以及静息眼压与C的比值（P(0)/C）。在眼压描记法检查5年后对受试者进行青光眼复查。
7名受试者因先前已知会改变房水流出易度的治疗而被排除。与23名非携带者的眼睛相比，12名携带Thr377Met突变的受试者眼睛的平均流出易度在使用C（P<0.001）和P(0)/C（P<0.001）时均显著降低。在那些使用C（P = 0.015）和P(0)/C（P = 0.001）测量时尚未表现出青光眼或高眼压临床体征的突变携带者中，也证明了流出易度降低。5年后，5名肌纤凝蛋白突变携带者发生了青光眼进展，其中2名表现为双侧进展；3名携带者仍完全正常。4名受试者一开始就患有双侧青光眼且病情未变。与保持正常的携带者眼睛相比，向青光眼进展的携带者眼睛的流出易度降低，尽管差异无统计学意义。
肌纤凝蛋白Thr377Met突变携带者的流出易度降低，这可能在发生青光眼之前就被检测到。眼压描记法在预测青光眼进展方面在临床上未见有用。
