TY - JOUR
T1 - Narrow angles and angle closure
T2 - Anatomic reasons for earlier closure of the superior portion of the iridocorneal angle
AU - Dorairaj, Syril K.
AU - Tello, Celso
AU - Liebmann, Jeffrey M.
AU - Ritch, Robert
PY - 2007/6
Y1 - 2007/6
N2 - Objective: To quantitatively investigate the ultrasound biomicroscopic features of eyes with asymmetric narrowing of the iridocorneal angles. Methods: Asymmetric angles were defined as those differing by 2 or more Shaffer grades between the superior and inferior angles. We performed ultrasound biomicroscopy on 18 eyes in 18 patients. Measurements of the following were made: the angle recess area, the triangular area bordered by the anterior iris surface, the corneal endothelium, and a line drawn from 750 μm anterior to the scleral spur; the y-intercept, the estimated angle opening distance at the level of the scleral spur; acceleration, which describes how rapidly the angle widens from the iris root; trabecular-ciliary process distance, the distance between the trabecular meshwork and the ciliary body at 500 μm anterior to the scleral spur; and angle recess-iris insertion distance, the distance between the apex of the angle recess and the iris insertion on the ciliary body face. Results: In the superior angle, 11 eyes developed appositional closure, 10 with B-type (apposition beginning at the iris root) and 1 with S-type (apposition beginning at the line of Schwalbe). Four eyes also had apposition inferiorly (1 B-type and 3 S-types). The y-intercept, angle recess areas, trabecular-ciliary process distance, and angle recess-iris insertion distance were significantly smaller in the superior quadrant. S-type angles predominated in the inferior angle, and B-type angles did in the superior angle, indicating a more posterior insertion of the iris in the wider inferior angles. Conclusions: Asymmetry in eyes with narrow angles occurs because of differences in iris insertion position on the ciliary body face and from asymmetry of the ciliary body position.
AB - Objective: To quantitatively investigate the ultrasound biomicroscopic features of eyes with asymmetric narrowing of the iridocorneal angles. Methods: Asymmetric angles were defined as those differing by 2 or more Shaffer grades between the superior and inferior angles. We performed ultrasound biomicroscopy on 18 eyes in 18 patients. Measurements of the following were made: the angle recess area, the triangular area bordered by the anterior iris surface, the corneal endothelium, and a line drawn from 750 μm anterior to the scleral spur; the y-intercept, the estimated angle opening distance at the level of the scleral spur; acceleration, which describes how rapidly the angle widens from the iris root; trabecular-ciliary process distance, the distance between the trabecular meshwork and the ciliary body at 500 μm anterior to the scleral spur; and angle recess-iris insertion distance, the distance between the apex of the angle recess and the iris insertion on the ciliary body face. Results: In the superior angle, 11 eyes developed appositional closure, 10 with B-type (apposition beginning at the iris root) and 1 with S-type (apposition beginning at the line of Schwalbe). Four eyes also had apposition inferiorly (1 B-type and 3 S-types). The y-intercept, angle recess areas, trabecular-ciliary process distance, and angle recess-iris insertion distance were significantly smaller in the superior quadrant. S-type angles predominated in the inferior angle, and B-type angles did in the superior angle, indicating a more posterior insertion of the iris in the wider inferior angles. Conclusions: Asymmetry in eyes with narrow angles occurs because of differences in iris insertion position on the ciliary body face and from asymmetry of the ciliary body position.
UR - http://www.scopus.com/inward/record.url?scp=34250353984&partnerID=8YFLogxK
U2 - 10.1001/archopht.125.6.734
DO - 10.1001/archopht.125.6.734
M3 - Article
C2 - 17562981
AN - SCOPUS:34250353984
SN - 0003-9950
VL - 125
SP - 734
EP - 739
JO - Archives of Ophthalmology
JF - Archives of Ophthalmology
IS - 6
ER -