Ultrasound biomicroscopy helps with placement of capsular tension device in eyes with lens subluxation

Santiago, Chile-Analysis of the characteristics of capsular tension devices in eyes with lens subluxation indicates that in the medium term following cataract surgery, these devices seem to maintain stability in the eye and the correct anatomic positioning, according to Juan J. Mura, MD.

Dr. Mura, instructor of ophthalmology, University of Chile, Santiago, and his colleagues analyzed the long-term follow-up in these cases of traumatic or congenital origin and reported their results at the American Society of Cataract and Refractive Surgery annual meeting in San Francisco.

"In cases of extensive zonular absence or damage, the suture fixation or capsular tension devices provide optimal positioning and stability of the IOL in some cases," he said.

Fixation is achieved by passing the iris retractor through the hook eyelet, which minimizes the risk of complications.

"Implantation of the lens into the bag is the best option for visual rehabilitation," Dr. Mura said. "We believe that the use of the IOL in the capsular bag is similar to the optics of the natural crystalline lens, avoids the lens coming into contact with uveal structures, and reduces the incidence of IOL decentration."

Ultrasound biomicroscopy

Ultrasound biomicroscopy was used, he explained, to clarify the position of the suture, the depth of the anterior chamber, the presence of vitreous incarceration, and focal abnormalities of the iris.

Eight eyes of seven patients were included in this analysis of the capsular tension device during cataract surgery, although two women and six men had undergone the procedure (patient age range, 33 to 75 years; mean, 50 years). The procedures were performed by two surgeons. Ultrasound biomicroscopy at 50 MHz (resolution, 40 μm) was performed preoperatively and postoperatively. The follow-up ranged from 6 to 26 months (mean, 20 months). Mean preoperative best-corrected visual acuity (BCVA) was 1.2 ± 1.2 logMAR and mean postoperative BCVA was 0.2 ± 0.1 logMAR.

The suture eyelet was positioned in the sulcus in six CTSs (54%) and in the ciliary process in five CTSs. In three patients, two capsular tension devices were used. Five patients had one CTS and three patients had two CTSs (11 CTSs in eight eyes of seven patients).

"We did not identify any alterations in the anatomy of the iris, no pigment dispersion, iris erosion, or secondary glaucoma. None of the IOLs were tilted. There also were no synechiae or vitreous incarceration," Dr. Mura reported.

He also explained that different corrective devices, such as artificial eyes, could be used with this procedure.

"In the medium term, the capsular tension segment appears to maintain stability and achieve proper anatomic positioning," he concluded.