Instillation of sodium hyaluronate into the anterior chambers of enucleated human eyes caused a 65% decrease in outflow facility (from 0.33 +/- 0.16 microliters/min/mm Hg to 0.08 +/- 0.02 microliters/min/mm Hg). Vigorous anterior chamber irrigation, performed either immediately or three hours after introduction of the sodium hyaluronate, failed to relieve this obstruction. However, irrigation with hyaluronidase restored the facility values to baseline. Tying limbal or corneal 9-0 nylon sutures (for example, in cataract surgery), followed by instillation of sodium hyaluronate into the anterior chamber and subsequent irrigation, produced an overall decrease of 76% in outflow facility (final outflow values were 0.08 +/- 0.03 microliters/min/mm Hg in eyes with corneal wounds and 0.08 +/- 0.04 microliter/min/mm Hg in eyes with limbal wounds). Postoperative intraocular pressure should be monitored closely when sodium hyaluronate is used in cataract surgery. Irrigating the anterior chamber with balanced salt solution after using sodium hyaluronate does not eliminate the possibility of severe postoperative glaucoma.