Horizontal vs Vertical Scleral Tunnels in Flanged IOL Fixation

NCT07701980 | Completed

• 1 other identifier: GOKAEK-2024-04-02
• Study Type: observational
• Target: 107
• Locations: 1 country
• Sites: 1

Brief Summary

This study compares the 2-year outcomes of horizontal versus vertical scleral tunnel orientation in flanged intrascleral intraocular lens (IOL) fixation surgery. The primary outcome is the proportion of eyes achieving refraction within ±0.50 diopters of the target at 2 years. Secondary outcomes include IOL tilt measured by anterior segment optical coherence tomography (AS-OCT), iris capture, conjunctival erosion, and other complications. The study aims to determine whether tunnel orientation is associated with differing outcomes in this surgical technique.

Conditions

Intraocular Lens Dislocation; Aphakia - No Lens Capsule

Keywords

Flanged intrascleral IOL fixation; Yamane technique; scleral tunnel orientation; IOL tilt

Outcome Measures

Primary Outcomes (1)

• Proportion of Eyes Achieving Mean Absolute Error (MAE) Within ±0.50 Diopters of Target Refraction

  The proportion of eyes achieving mean absolute error (MAE) within ±0.50 diopters of the target spherical equivalent refraction at 24 months postoperatively.

  24 Months

Secondary Outcomes (2)

• Mean Absolute Error (MAE) at 2 Years

  24 Months

• IOL Tilt Angle

  24 Months

Study Arms (2)

Vertical Scleral Tunnel Group

Patients who underwent flanged intrascleral IOL fixation with scleral tunnels created perpendicular to the limbus (radial/vertical orientation).

Procedure: Flanged Intrascleral IOL Fixation (Yamane Technique)

Horizontal Scleral Tunnel Group

Patients who underwent flanged intrascleral IOL fixation with scleral tunnels created parallel to the limbus (tangential/horizontal orientation).

Procedure: Flanged Intrascleral IOL Fixation (Yamane Technique)

Interventions

Flanged Intrascleral IOL Fixation (Yamane Technique) PROCEDURE

Sutureless flanged intrascleral fixation of a three-piece foldable acrylic IOL (Alcon AcrySof MA60AC). Two partial-thickness scleral tunnels are created 2.0 mm posterior to the limbus, 180° apart. Haptics are externalized through the tunnels, and a flange is created on each haptic tip using thermal cautery. Tunnel orientation varied intentionally: horizontal (parallel to limbus) or vertical (perpendicular to limbus).

Horizontal Scleral Tunnel Group; Vertical Scleral Tunnel Group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with aphakia, crystalline lens luxation, or intraocular lens luxation in the absence of adequate capsular support who underwent flanged intrascleral IOL fixation surgery at a single tertiary referral centre between March 1, 2022, and March 1, 2025. All patients were aged 18 years or older and completed 24 months of follow-up.

You may qualify if:

• Age ≥ 18 years
• Complicated aphakia defined as absence of adequate capsular support following cataract extraction, lens trauma, or previous lensectomy
• Crystalline lens luxation defined as partial or complete displacement of the natural lens due to zonular weakness
• Intraocular lens (IOL) luxation defined as partial or complete dislocation of a previously implanted IOL
• Inadequate capsular support (\<180° of intact zonular or capsular support)
• Ability to complete scheduled follow-up visits
• Complete follow-up data available

You may not qualify if:

• Previous scleral buckling surgery within 6 months
• Pars plana vitrectomy within 3 months
• Active uveitis
• Active endophthalmitis
• Uncontrolled scleritis or scleral thinning
• Corneal decompensation (endothelial cell density \<1000 cells/mm²)
• Uncontrolled glaucoma (IOP \>25 mmHg despite maximum therapy)
• History of penetrating keratoplasty, DALK, DSEK, or DMEK
• History of corneal refractive surgery
• Active proliferative diabetic retinopathy
• Pregnancy or breastfeeding
• Inability to complete 24-month follow-up

Sponsors & Collaborators

• Yuzuncu Yil University: lead

Study Sites (1)

SBU Van Training and Research Hospital

Van, 65000, Turkey (Türkiye)

Location

Related Publications (1)

• Yamane S, Sato S, Maruyama-Inoue M, Kadonosono K. Flanged Intrascleral Intraocular Lens Fixation with Double-Needle Technique. Ophthalmology. 2017 Aug;124(8):1136-1142. doi: 10.1016/j.ophtha.2017.03.036. Epub 2017 Apr 27.

  PMID: 28457613 RESULT

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: OTHER
• Target Duration: 24 Months
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Clinical Professor

Study Record Dates

• First Submitted: July 1, 2026
• First Posted: July 14, 2026
• Study Start: March 1, 2022
• Primary Completion: March 1, 2025
• Study Completion: March 1, 2025
• Last Updated: July 14, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)