Phacoemulsification with aspirated or retained Viscoat.

Endothelial cell counts, morphology, and 24-hour postoperative intraocular pressure (IOP) changes were measured in 55 consecutive patients (60 eyes) who had uncomplicated phacoemulsification and posterior chamber lens implantation with either aspirated (30 eyes) or retained (30 eyes) Viscoat (sodium chondroitin sulfate-sodium hyaluronate). The surgical technique was standardized in all cases. Endothelial cell loss was almost identical in the aspirated and in the retained groups (8.8% and 8.7%). Postoperative pleomorphism was significantly less in the retained Viscoat group than in the aspirated group, suggesting a possible protective effect of the retained viscoelastic. Corneal thickness increased significantly in the retained Viscoat group, but this was not significant clinically. The retained Viscoat group had more patients with a postoperative IOP greater than 30 mm Hg and a greater mean increase in postoperative IOP, although the difference between the groups was not significant. The IOP changes may have been caused by blockage of the trabecular meshwork by the retained Viscoat. The results suggest that Viscoat can be retained after cataract surgery if the surgeon is prepared for a greater 24-hour postoperative increase in IOP.

Topical 2.5% and 5% phenylephrine: comparison of effects on heart rate and blood pressure.

We compared the effects of 2.5% and 5% concentrations of topical ocular phenylephrine hydrochloride on blood pressure and heart rate in 200 adult patients undergoing extracapsular cataract surgery under either general or neuroleptic anesthesia. Although there was little initial change in mean systolic or diastolic blood pressure in either group, once anesthesia was induced there was a rise of 1 to 5 mm Hg in the lower-dose group, compared with 17 to 26 mm Hg in the higher-dose group. A slight decrease in mean heart rate of 5 to 6 beats/min was noted immediately after the instillation of either the 2.5% or 5% solution. The results suggest that lower doses of topical phenylephrine are safer than higher doses when used preoperatively. This may be particularly significant in hypertensive patients, who have higher baseline blood pressure.