Comparison of the performance and safety of 2 ophthalmic viscosurgical devices in cataract surgery.

PURPOSE: To compare the clinical performance and safety of 2 ophthalmic viscosurgical devices (OVDs)-Twinvisc (OVD 1) and Duovisc (OVD 2)-in cataract surgery. SETTING: European multicenter study. DESIGN: Prospective randomized controlled study. METHODS: Patients with cataract had phacoemulsification and intraocular lens implantation in 1 eye. They were randomly assigned to receive OVD 1 or OVD 2. Preoperative and postoperative examinations over 3 months included mean intraocular pressure (IOP), incidence of IOP peaks (≥30 mm Hg and ≥24 mm Hg), endothelial cell count (ECC), corneal thickness, and intraocular inflammation. A subjective evaluation of the OVDs was performed. RESULTS: The study comprised 220 patients. The incidence of IOP peaks and the mean IOP were not statistically significantly different between the 2 groups at any of the follow-up visits. At 6 hours, the incidence of IOP spikes 30 mm Hg or higher was 6.5% and 7.2% in the OVD 1 and the OVD 2 groups, respectively (P = .846). For the IOP spikes 24 mm Hg or higher, the incidence was 16.8% and 25.2%, respectively (P = .128). Three months postoperatively there was no statistically significant difference in ECC and pachymetry between the 2 groups. Mild inflammation was noticed up to 7 days postoperatively after which it resolved in both groups. Subjectively, the OVD 2 was easier to use, whereas the OVD 1 had better cohesive and dispersive properties. CONCLUSIONS: Both OVDs have similar performance and safety profiles in phacoemulsification cataract surgery. No clinically relevant differences were found between the 2 devices regarding transient IOP spikes, mean IOP, corneal endothelium injury, or inflammation.

Changes in visual function under mesopic and photopic conditions after intrastromal corneal ring segment implantation for different stages of keratoconus.

PURPOSE: To analyze and compare the changes in visual function under mesopic and photopic conditions in different stages of keratoconus before and after Keraring intrastromal corneal ring segment (ICRS) implantation. SETTING: Clinico San Carlos Hospital and Faculty of Optics and Optometry, Complutense University, Madrid, Spain. DESIGN: Case series. METHODS: Keratoconic eyes were evaluated under mesopic (0.1 to 0.2 candelas [cd]/m(2)) and photopic (85 cd/m(2)) conditions. LogMAR high-contrast corrected distance visual acuity (CDVA) and low-contrast CDVA were assessed using the Bailey-Lovie test and logarithmic contrast sensitivity, using the Pelli-Robson test. RESULTS: The study evaluated 12 eyes with stage I keratoconus, 21 eyes with stage 2, and 14 eyes with stage 3. The mean change in photopic high-contrast CDVA was 0.16 logMAR ± 0.20 (SD) (P<.00001). Photopic low-contrast CDVA increased by a mean of 0.14 ± 0.26 logMAR (P=.0005), photopic contrast sensitivity by a mean of 0.09 ± 0.22 logMAR (P=.005), and mesopic high-contrast CDVA by a mean of 0.10 ± 0.26 logMAR (P=.03). There were no significant differences between stages. Surgery did not affect the mean changes in mesopic low-contrast CDVA or mesopic contrast sensitivity for any stage. CONCLUSIONS: Implantation of ICRS in keratoconic eyes increased photopic high-contrast CDVA, low-contrast CDVA, and contrast sensitivity. Under low luminance, the mean changes in high-contrast CDVA, low-contrast CDVA, and contrast sensitivity did not worsen after ICRS implantation performed 5.0 mm from the visual axis, despite the rings being partially superimposed on the mydriatic pupil.