Đang chuẩn bị liên kết để tải về tài liệu:
Angle Closure and Angle Closure Glaucoma - part 3

Sự xuất hiện siêu âm biomicroscopic của mắt bình thường. Các giác mạc (C), trước buồng (AC), iris (I), ống kính (L), viên nang ống kính (LC), sau buồng (PC), góc (mũi tên), scleral thúc đẩy mỏng mũi tên, Schwalbe của dòng (dày mũi tên) màng cứng (S), và cơ thể lông mi (CB) có thể nhìn thấy. | 8 P. Foster M. He J. Liebmann Fig. 1. The ultrasound biomicroscopic appearance of normal eye. The cornea C anterior chamber AC iris I lens L lens capsule LC posterior chamber PC angle arrow scleral spur thin arrow Schwalbe s line thick arrow sclera S and ciliary body CB are visible. On gonioscopy the iris root angulates forward and then centrally. The iris root may be short and inserted anteriorly on the ciliary face producing a shallow narrow angle with a sharp drop-off of the peripheral iris. Before iridotomy the anterior chamber is usually of medium depth and the iris surface mildly convex. Laser iridotomy either fails to open the angle or opens it only partially. Argon laser peripheral iridoplasty may open the angle in this circumstance. Regarding plateau iris there is no precise quantitative definition of how narrow the angle has to be or how anteriorly positioned the ciliary processes must be before the diagnosis of plateau iris is made.43 44 There are many causes of an apparent plateau iris configuration.45 The absence of ciliary sulcus was observed in 41 9 22 eyes with open angle angle-opening distance measured using UBM at 500 microns from the scleral spur AOD500 130 microns after iridotomy suggesting that this finding is not necessarily related to an anterior positioning of the ciliary process.46 Plateau iris syndrome refers to the development of angle closure either spontaneously or after pupillary dilation in an eye with plateau iris configuration despite the presence of a patent iridotomy. Some patients may develop acute angle closure. The extent or the height to which the plateau rises determines whether the angle will close completely or only partially. The angle can narrow further with age due to enlargement of the lens so that an angle with plateau configuration which does not close after iridotomy may do so some Epidemiology Classification and Mechanism 9 Fig. 2. A. The effect of illumination on angle configuration bright illumination . Under .