Clinical Evaluation Of DisCoVisc Ophthalmic Viscosurgical Device In Phacoemulsification

Objective:To evaluate the protective effect on corneal endothelium and safety of DisCoVisc ophthalmic viscosurgical devices in phacoemu-lsification.Methods:143eyes of118patients with age related cataract that received phacoemulsification and foldable intraocular lens implantation were selected from May2012to May2013. All patients were randomly divided into two groups based on the type of ophthalmic viscosurgical device(OVD) used during surgery:73eyes using DisCoVisc(DisCoVisc group) and70eyes using Sodium hyaluronate(control group). In each group, eyes were further classified into two types according to the nuclear opacity (Emery-Little classification). The first type was soft nuclear cataract(Ⅱ～Ⅲ grade), including40eyes in DisCoVisc group and38eyes in control group. The second type was hard nuclear cataract(≥Ⅳ grade), including33eyes in DisCoVisc group and32eyes in control group. The intraoperative parameter of Ultrasound Time(UST), Cumulative Dissipated Energy(CDE), and washout time to completely remove the OVD after IOL implantation were recorded. The visual acuity, intraocular pressure(IOP), corneal edema, corneal thickness, and corneal endothelial cell density were evaluated during the follow-up of3months.Results:(1) There was no statistically significant difference in UST, CDE and washout time between DisCoVisc group and control group (P>0.05).(2) The intraocular pressure showed no significant difference between DisCoVisc group and control group before surgery and1day,1week,1month after surgery (P>0.05).(3) In patients with soft nuclear cataract, the proportion of patients with uncorrected visual acuity≥0.5at1day,1week,1month after surgery showed no significant difference between DisCoVisc group and control group (P>0.05). In patients with hard nuclear cataract, the proportion of patients with uncorrected visual acuity≥0.5at1day after surgery was72.7%in DisCoVisc group and46.9%in control group (P<0.05), the proportion of patients with uncorrected visual acuity>0.5at1week,1month after surgery showed no significant difference between the two groups (P>0.05).(4)In patients with soft nuclear cataract, there was no significant difference in overall incidence of corneal edema at1day after surgery between the two groups. At1week and1month after surgery, the two groups had no corneal edema. In patients with hard nuclear cataract, the overall incidence of corneal edema at1day after surgery was18.2%in DisCoVisc group and43.8%in control group, the difference was significant (P<0.05). The overall incidence of corneal edema at1week after surgery showed no significant difference between the two groups (P>0.05). At1month after surgery, the two groups had no corneal edema.(5) There was no significant difference in preoperative central corneal thickness between the two groups in both soft and hard nuclear cataract patients (P>0.05) In patients with soft nuclear cataract, the mean increase of central corneal thickness had no significant difference between the two groups at lday,1week and1month after surgery (P>0.05). In patients with hard nuclear cataract, the mean increase of central corneal thickness at1day after surgery was40.87±24.52pm in DisCoVisc group and64.53±28.22μm in control group(P<0.05), the mean increase of central corneal thickness at1week and1month after surgery had no significant difference between the two groups (P>0.05).(6) There was no significant difference in preoperative corneal endothelial cell density between the two groups in both soft and hard nuclear cataract patients (P>0.05). In patients with soft nuclear cataract, the rate of corneal endothelial cell loss3month after surgery had no significant difference (P>0.05). In patients with hard nuclear cataract, the rate of corneal endothelial cell loss3month after surgery was12.56±5.46%in DisCoVisc group and19.61±6.79%in control group (P<0.05).Conclusions:DisCoVisc was safe and effective for the cataract surgery. For the patients with hard nuclear cataract, DisCoVisc had superior protective effect on corneal endothelial cells compared with sodium hyaluronate.