Increase in iris-lens contact after laser iridotomy for pupillary block angle closure.
OBJECTIVE
To quantitate changes in anterior ocular segment anatomy after laser iridotomy for pupillary block angle closure.


METHODS
We prospectively performed ultrasound biomicroscopy and A-scan biometry in 13 eyes of 13 consecutive untreated patients with relative pupillary block and appositional angle closure, without peripheral anterior synechiae on indentation gonioscopy. A radial, perpendicular image in the horizontal temporal meridian was obtained with ultrasound biomicroscopy before and one week after laser iridotomy in each eye.


RESULTS
Mean age of the 13 patients was 69.3 +/- 1.8 (S.E.) years, mean refractive error was +1.37 +/- 0.39 diopters, and mean axial length was 22.54 +/- 0.20 mm. In 13 eyes, before and after laser iridotomy measurements of angle-opening distance (0.11 +/- 0.02 vs. 0.18 +/- 0.02 mm) (P = .0004; paired t test), angle aperture (8.3 +/- 1.3 vs 18.6 +/- 2.8 degrees) (P = .0003) and iris-lens contact distance (0.58 +/- 0.06 vs 1.18 +/- 0.14 mm) (P = .0003) were greater postoperatively, but anterior chamber depth was unchanged (P = .7).


CONCLUSIONS
Flattening of the iris after laser iridotomy for pupillary block causes an increase in iris-lens contact. The change in angle configuration after iridotomy results more from an alteration in aqueous pressure gradients across the iris rather than from posterior lens movement.
Caronia
R M
RM
Department of Ophthalmology, New York Eye and Ear Infirmary, NY 10003, USA.
Liebmann
J M
JM
Stegman
Z
Z
Sokol
J
J
Ritch
R
R
D000368:Aged; D000369:Aged, 80 and over; D000867:Anterior Chamber / Q000473:pathology; D000869:Anterior Eye Segment / Q000000981:diagnostic imaging; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000601:surgery*; D006801:Humans; D007498:Iris / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D053685:Laser Therapy; D007908:Lens, Crystalline / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011680:Pupil; D014463:Ultrasonography