Long-term Clinical Outcomes of a Modified Yamane Technique for Intrascleral Sutureless Posterior Chamber Intraocular Lens Fixation.

Abstract

To evaluate long-term outcomes of the modified Yamane technique using 25-gauge needles, focusing on flange-based intrascleral intraocular lens (IOL) stability and prolonged effects on surrounding tissues. Prospective, consecutive, interventional case series. 69 patients (75 eyes) undergoing the modified Yamane surgery with at least one year of follow-up. Anterior segment optical coherence tomography CASIA2 was utilized to quantify biometric parameters related to intrascleral haptics and adjacent ocular tissues in surgical eyes. Main outcome measures were the differences in scleral thickness (ST) at three key locations along the scleral tunnel traversed by IOL haptic compared to adjacent sites at both the 2- and 8-o'clock position, including: the flanged haptic end (ST₁), the scleral penetrating end (ST₃), and the intermediate position (ST₂). Additionally, when flanges were exposed outside the tunnel and beneath the conjunctiva, conjunctival thickness at these sites was compared with adjacent control areas. Over a median follow-up of 3.3 years (range, 1.1-7.0 years; 16 eyes ≥5 years), no instances of IOL dislocation were observed. Postoperative uncorrected distance visual acuity and best corrected visual acuity demonstrated significant improvement compared with preoperative levels (both P < .001). ST₁ and ST₂ exhibited significant thickening versus adjacent scleral positions at both the 2- and 8-o'clock positions (all P < .05). ST₃ at the 2-o'clock position showed significant thinning (P < .05), while not at the 8-o'clock position (P > .05). Furthermore, eyes followed ≥5 years postoperatively exhibited no progressive thinning at intrascleral haptic sites. The flange exposure rate was 14.0% (21/150 flanges), with significantly thinner conjunctival thickness observed at these sites compared to adjacent areas (P < .05). Multivariate logistic regression analysis identified white-to-white distance as a protective factor (Odds ratio [OR] = 0.082, P = .017) and flange diameter as a risk factor (OR = 1.012, P = .023) for flange exposure. The modified Yamane technique showed great long-term stability, with no IOL dislocation observed over a median follow-up of 3.3 years (up to 7 years). Changes in tissue thickness around haptics along the scleral tunnel may enhance stability. Conjunctival thinning occurs over flange exposure sites. Flanges should therefore be confirmed fully positioned into scleral tunnels when concluding surgery, with haptic length trimmed if necessary.