Influence of irrigation dynamic pressure-assisted hydrodissection on intraocular pressure and the posterior chamber-anterior hyaloid membrane barrier during cataract surgery

Purpose To evaluate the effects of irrigation dynamic pressure-assisted hydrodissection (irrigation-hydro: iH) on intraocular pressure (IOP) and the posterior chamber-anterior hyaloid membrane (PC-AHM) barrier in porcine eyes. Study design Experimental. Methods In Experiment 1, IOP was recorded while irrigating the anterior chamber (AC), during iH, and during phacoemulsification and aspiration in 20 porcine eyes using bottle heights of 50, 70, and 90 cm. Under the same conditions, IOP was recorded during conventional manual cortical cleaving hydrodissection (manual hydro: mH) in 20 porcine eyes. In Experiment 2, after iH, ACs were perfused for 5 seconds with balanced salt solution containing 1.0-μm fluorescein beads in 20 porcine eyes using bottle heights of 70, 118, and 169 cm. PC-AHM barrier staining grade was evaluated by the Miyake-Apple view. Results iH proved successful in all cases. In Experiment 1, IOP during iH was relatively stable and peak IOP was below the baseline bottle height-dependent pressure. No eyes showed a peak IOP > 75 mmHg during iH, but 8 eyes showed a peak IOP > 75 mmHg during mH. In Experiment 2, neither AHT nor ruptured capsules were observed at any bottle height. Conclusion Unlike mH, IOP during iH was relatively stable without any high peak IOP. Thus, iH offers a simple technique for reducing peak IOP and avoiding disturbance of the PC-AHM barrier.