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. CONCLUSION: Changes in intraocular pressure can disrupt the posterior chamber-AHM barrier during PEA. CLINICAL RELEVANCE: Cataract surgeons should reexamine their surgical settings to avoid unnecessary stress on the eye.