An Update on the Yamane Technique By Dr.Knezevic & Dr.Fram

An Update on the Yamane Technique

Pearls for successful IOL fixation.

The double-needle, sutureless intrascleral haptic fixation (ISHF) technique was originally described by Yamane et al in 2017.¹ The technique’s advantages include a small incision, short operating time, and lower risk of postoperative hypotony compared to larger-incision scleral fixation techniques. This technique, however, is associated with a steep learning curve to avoid tilt and decentration. A wave of a modified intrascleral fixation techniques have subsequently been described.^2,3 Identifying when adjustment is necessary can result in a safer outcome. This article shares our suggestions and observations to help surgeons in search of the perfect fixation technique.

SETTING UP FOR SUCCESS

The double-flanged ISHF technique is an elegant approach to secondary IOL fixation. The best IOLs for ISHF are the CT Lucia 602 (Carl Zeiss Meditec) and Tecnis monofocal three-piece (model ZA9003 or AR40e, Johnson & Johnson Vision). Ideal materials include 30-gauge thin wall needles (TSK) on a tuberculin syringe filled with balanced salt solution, Duet forceps (MicroSurgical Technology), low-temperature cautery to create the flanged haptic, and infusion. Infusion can be accomplished through an anterior

chamber maintainer or pars plana trocar. Most importantly, a thorough pars plana–assisted or limbus-based anterior vitrectomy should be performed before or concomitant with surgery. Fortunately, many patients requiring this procedure have already had a pars plana vitrectomy that adds to the safety of the implantation maneuvers.

Reproducibility improves the likelihood of achieving safe and predictable outcomes. Yamane et al described the steps for attaining optimal outcomes.^1,4 These include placing marks at 180º for X/Y centration, directing the scleral tunnel at a 15º to 20º angle toward the limbus, using a 5º posterior entry to avoid deformation of the haptics, and entering the eye 2 to 2.5 mm posterior to the limbus depending on the white-to-white distance (Figure 1; Video). The steps of the procedure are described in The Technique in Detail. Standardization of the ISHF technique, however, is challenging in the setting of conjunctival chemosis and inevitable variations in tunnel length and entry. Markers have come to market that attempt to address some of these issues.

Proper anesthesia is important to success. A retrobulbar or sub-Tenon block is preferred because scleral tunnels are involved. Many have recommended choosing a refractive target of -0.50 to 0.75 D to achieve emmetropia.⁵

COMPLICATIONS AND INTERVENTION

ISHF remains a two-point fixation technique that can result in IOL tilt, decentration, and pupillary capture. Ignoring these issues both during and after surgery can lead to pigment dispersion, uveitis-glaucoma-hyphema syndrome, iris and transillumination defects, cystoid macular edema, and an undesirable refractive outcome.

Find the full article - https://crstoday.com/articles/apr-2023/an-update-on-the-yamane-technique