[Effect of viscoelasticity on corneal endothelial cell loss in phacoemulsification]

One of the most important factors for successful intraocular surgery is deep anterior chamber which is maintained using viscoelastics that protect corneal endothelial cells. This single endothelial cell layer may sustain a varying degree of injury during surgery and is known to be incapable of regeneration.

Of the study was to determine optimal visoelastics for the protection of corneal endothelial cells during phacoemulsification and intraocular lens implantation.

A series of 156 patients were included in this prospective study. Patients were randomly assigned to three groups based on the type of viscoelastics used. In the first group, 1.4% sodium hyaluronate, in the second group a combination of 4% sodium chondroitin sulfate and 3% sodium hyaluronate, and in the third group 3% hyaluronate was used. Endothelial cell count and morphology changes were determined centrally with a specular microscope on the day before, on day 7 and one month after surgery. Intraocular pressure was measured before surgery, and at 6 hours, 24 hours, 7 days and 30 days of the surgery. Pachymetry as a measure of "endothelial pump" function was evaluated before surgery and 7 and 30 days postoperatively. All surgeries were performed by two surgeons using the same technique.

Endothelial cell loss was lowest (16.1%) in the eyes protected with a combination of 4% sodium chondroitin sulfate and 3% sodium hyaluronate. In the groups where 1.4% sodium hyaluronate and 3% hylunorate were used, the loss was 7.6%; and 7.9%, respectively. Although endothelial cell loss was not significantly different among the three groups, the lowest morphology change rate recorded in group 2 suggested that a combination of chondroitin and hyaluronate offered the best endothelial protection. There was no statistically significant difference in the postoperative intraocular pressure increase and pachymetry values among the study groups.