Disruption of the posterior chamber-anterior hyaloid membrane barrier during phacoemulsification and aspiration as revealed by contrast-enhanced magnetic resonance imaging.
OBJECTIVE
To determine the effect of phacoemulsification and aspiration (PEA) in different surgical settings on the posterior chamber-anterior hyaloid membrane (AHM) barrier.


METHODS
Eighty enucleated porcine eyes divided into 8 groups underwent lens extraction at a bottle height of 35 or 95 cm by 1 of the following 4 procedures: standard PEA, standard PEA without hydrodissection (sPEA-), sPEA- including 5 minutes of irrigation of the anterior chamber, and sPEA- including 20 cycles of deflation (5 seconds each cycle) and inflation (10 seconds each cycle) of the anterior chamber. Distribution of gadopentetate dimeglumine (gadolinium-diethylenetriamine pentaacetic acid [Gd-DTPA]) in the irrigating fluid was assessed by magnetic resonance imaging (MRI).


RESULTS
The most common MRI pattern was the posterior chamber type, where Gd-DTPA was localized in the anterior and posterior chambers, followed by AHM detachment, in which Gd-DTPA was evident beneath the posterior lens capsule. The least common was AHM tear, in which Gd-DTPA entered the vitreous cavity through a tear in the AHM. Logistic regression analysis revealed prolonged irrigation (P< .001) and deflation/inflation of the anterior chamber (P< .001) as risk factors for AHM detachment and hydrodissection (P= .04) as a risk factor for AHM tear.


CONCLUSIONS
Changes in intraocular pressure can disrupt the posterior chamber-AHM barrier during PEA.


CONCLUSIONS
Cataract surgeons should reexamine their surgical settings to avoid unnecessary stress on the eye.
Department of Ophthalmology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-City, Ehime 791-0295, Japan. skawasak@m.ehime-u.ac.jp
Shiro
S
Kawasaki
Takashi
T
Suzuki
Masahiko
M
Yamaguchi
Yoshitaka
Y
Tasaka
Atsushi
A
Shiraishi
Toshihiko
T
Uno
Masanori
M
Sadamoto
Noriyoshi
N
Minami
Kiyokazu
K
Naganobu
Yuichi
Y
Ohashi
D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism / Q000473:pathology*; D003287:Contrast Media; D019786:Gadolinium DTPA; D007429:Intraocular Pressure; D007431:Intraoperative Complications; D007903:Lens Capsule, Crystalline; D008279:Magnetic Resonance Imaging; D008566:Membranes / Q000473:pathology*; D018918:Phacoemulsification; D013396:Suction; D013552:Swine; D000267:Tissue Adhesions; D014822:Vitreous Body / Q000378:metabolism / Q000473:pathology*
D003287:Contrast Media; D019786:Gadolinium DTPA