Demonstration of aqueous streaming through a laser iridotomy window against the corneal endothelium.
OBJECTIVE
To determine the pathogenesis of the bullous keratopathy that is frequently observed in patients after argon laser iridotomy (ALI) by comparing the changes in aqueous flow after ALI with those that follow peripheral iridectomy in rabbit eyes.


METHODS
Silicone particles were injected into the anterior chamber of rabbit eyes as tracers to monitor aqueous flow. Particle tracking velocimetry with image analysis was used to determine the direction and speed of aqueous flow in 5 pigmented rabbits that underwent ALI and 5 that underwent peripheral iridectomy.


RESULTS
In the ALI group, silicone particles were found to stream through the iridotomy window against the corneal endothelium immediately after the pupil was constricted by a light stimulus. The mean +/- SD speed of the particles was 2.97 +/- 1.51 mm/s. In contrast, the mean +/- SD flow rate through the iridectomy window in the peripheral iridectomy group was significantly slower at 0.36 +/- 0.30 mm/s (P = .01).


CONCLUSIONS
Constriction of the pupil elicited marked aqueous streaming through the ALI window against the corneal endothelium. Clinical Relevance The mechanical stress to the corneal endothelium by the abnormal aqueous stream may be partially responsible for the corneal decompensation that follows ALI.
Yamamoto
Yasuaki
Y
Department of Ophthalmology, Ehime University, Shitsukawa, Toon-city, Ehime, Japan. yyasuaki@m.ehime-u.ac.jp
Uno
Toshihiko
T
Shisida
Katsumi
K
Xue
Longquan
L
Shiraishi
Atsushi
A
Zheng
Xiaodong
X
Ohashi
Yuichi
Y
D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism*; D001082:Aqueous Humor / Q000378:metabolism*; D004728:Endothelium, Corneal / Q000378:metabolism*; D032801:Iridectomy; D007498:Iris / Q000378:metabolism* / Q000601:surgery*; D053685:Laser Therapy; D008863:Microspheres; D010030:Ostomy; D011680:Pupil / Q000502:physiology / Q000528:radiation effects; D011817:Rabbits; D012212:Rheology; D012826:Silicone Elastomers; D014741:Video Recording
D012826:Silicone Elastomers