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Comparative Outcomes of Double-Flanged, Conventional Sutured, and Intrascleral Haptic Fixation Techniques for Secondary Intraocular Lens Implantation

This retrospective study of 136 eyes found that while all three secondary intraocular lens fixation techniques yielded comparable visual and refractive outcomes, the double-flanged technique significantly reduced mechanical complications compared to conventional sutured and intrascleral haptic fixation methods.

Original authors: Sungho Yoo, Min Chul Shin, Sung Yeon Jun

Published 2026-08-15

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CC BY 4.0

Original authors: Sungho Yoo, Min Chul Shin, Sung Yeon Jun

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine your eye as a high-tech camera. Inside this camera sits a tiny, crucial lens that focuses light onto the film (your retina) so you can see the world clearly. Sometimes, due to injury, disease, or a previous surgery gone wrong, this natural lens or its artificial replacement gets lost, broken, or falls out of place. When the "mount" that holds the lens is missing, the lens can't stay put. To fix this, surgeons perform a rescue mission called scleral fixation. Think of the sclera as the tough, white outer shell of the eye. Since the internal mount is gone, surgeons have to build a new one by anchoring the lens directly to this outer shell.

For decades, the standard way to do this was like sewing a heavy curtain to a wall using a needle and thread (sutures). But threads can rot, knots can poke through, and the curtain might eventually sag. So, inventors came up with new tricks. One method is like tucking the lens's legs into little tunnels drilled into the wall, avoiding the thread entirely. Another newer method uses a clever four-point anchoring system with special "flanges" (little stoppers) to lock the lens in place from four different angles. The big question for eye doctors is: Which of these three methods is the best? Does one hold the lens steadier? Does one take less time? And does one cause less "wobble" that ruins the picture?

This study, conducted by researchers at Chuncheon Sacred Heart Hospital, set out to answer exactly that. They looked back at 136 eyes that had undergone one of these three rescue surgeries: the old-school conventional sutured method, the intrascleral haptic (tunnel) method, or the newer double-flanged method. They watched these patients for six months to see how well the lenses stayed put, how clear the vision was, and if any mechanical trouble (like the lens slipping or tilting) occurred.

Here is what they found. First, in terms of the final picture quality, all three methods were basically a tie. Whether the lens was sewn, tucked, or flanged, the patients ended up with similar sharpness of vision, similar eye pressure, and similar ability to focus. The "intrascleral haptic" (tunnel) method was the speed champion, taking significantly less time to perform than the other two. If you were a surgeon in a rush, that's a nice bonus.

However, when it came to keeping the lens from wobbling or slipping, the double-flanged technique was the clear winner. The study found that the double-flanged group had 0% mechanical complications—meaning the lens didn't tilt, dislocate, or get "captured" by the iris in any of those 44 eyes. In contrast, the conventional sutured group had a 12.2% complication rate, and the intrascleral haptic group had a 16.7% rate. That difference was statistically significant, suggesting that the four-point "flange" lock is much more stable than the other two methods.

There was one other interesting twist involving the "curtain" analogy. In the group that used the old-school sewing (conventional sutured) method, patients developed more astigmatism (a type of blurry vision caused by the lens tilting) after six months compared to their pre-surgery state. The other two groups didn't see this increase. This suggests that the sewing threads might loosen or pull unevenly over time, causing the lens to tilt slightly, whereas the newer methods keep the lens straighter.

So, while all three methods get the job done and give patients good vision, the double-flanged technique appears to be the most reliable for keeping that lens locked in place without wobbling, while the intrascleral haptic method is the fastest to perform. The study suggests that if stability is the top priority, the four-point flange system is a strong choice, though the researchers note that longer-term studies are still needed to see how these lenses hold up over many years.

Technical Summary: Comparative Outcomes of Scleral Fixation Techniques for Secondary IOL Implantation

Problem Statement
Scleral fixation of intraocular lenses (IOLs) is a critical surgical intervention for patients with aphakia, IOL dislocation, or insufficient capsular support. While conventional sutured scleral fixation has long been the standard, it is associated with complications such as knot exposure, suture degradation, and subsequent IOL instability. In response, sutureless alternatives like the intrascleral haptic fixation technique and the newer four-point double-flanged technique have been developed to improve stability and reduce suture-related risks. However, comparative studies evaluating the clinical outcomes, refractive results, and complication profiles among these three specific techniques (conventional sutured, intrascleral haptic, and double-flanged) remain limited.

Methodology
This retrospective comparative study analyzed 136 eyes that underwent secondary IOL implantation via scleral fixation at Chuncheon Sacred Heart Hospital between 2016 and 2025. To mitigate learning-curve effects, the first 10 cases of each technique were excluded. Only patients with a minimum follow-up of six months were included.

The cohort was divided into three groups:

Double-Flanged Group (n=44): Utilized four-eyelet IOLs (e.g., Adapt AO, Artis PL E) with four-point fixation at 2, 4, 8, and 10 o'clock positions. Sutures were secured with bulbs to prevent slippage.
Conventional Sutured Group (n=74): Utilized three-piece IOLs (e.g., Sensar AR40e, PC60AD) fixated with 10-0 polypropylene sutures passed through the sclera at 2 and 8 o'clock positions.
Intrascleral Haptic Fixation Group (n=18): Utilized three-piece IOLs (Sensar AR40e) with a sutureless approach. Haptics were externalized, flanged via cautery, and tucked into scleral tunnels created at 2 and 8 o'clock positions.

All procedures were performed by a single experienced surgeon. Outcomes measured included surgical time, best-corrected visual acuity (BCVA), intraocular pressure (IOP), refractive parameters (spherical equivalent and cylinder), and postoperative complications (specifically mechanical IOL-related issues like capture, dislocation, or subluxation) within the first six months. Statistical analysis employed ANOVA, Kruskal–Wallis tests, and chi-square/Fisher's exact tests, with Bonferroni correction for pairwise comparisons.

Key Results

Operative Time: The intrascleral haptic fixation technique demonstrated a significantly shorter operative time compared to both the double-flanged technique ( $p=0.045$ ) and the conventional sutured technique ( $p=0.050$ ). No significant difference was found between the double-flanged and conventional groups.
Visual and Refractive Outcomes: Postoperative BCVA, IOP, and spherical equivalent were comparable across all three groups at 1, 3, and 6 months.
Astigmatism: A significant increase in astigmatism (cylinder) was observed at 6 months in the conventional sutured group compared to preoperative values ( $p=0.002$ ). No significant changes in astigmatism were noted in the double-flanged or intrascleral haptic groups.
Mechanical Complications: The double-flanged technique demonstrated a significantly lower rate of mechanical IOL-related complications (0%) compared to the conventional sutured group (12.2%) and the intrascleral haptic fixation group (16.7%) ( $p=0.03$ ).
Other Complications: Rates of cystoid macular edema (CME), endophthalmitis, and other vitreoretinal complications did not differ significantly among the groups, though a numerical trend toward higher CME was noted in the double-flanged group (4.5%) compared to the conventional group (2.7%).

Significance and Claims
The authors claim that this study addresses a gap in the literature by providing direct comparative data among conventional sutured, intrascleral haptic, and double-flanged fixation techniques. The primary contribution is the identification of the double-flanged technique as a method that significantly reduces mechanical IOL-related complications (such as dislocation and subluxation) while maintaining functional outcomes comparable to the other methods. The authors attribute this enhanced stability to the four-point fixation mechanism, which offers superior centration and rotational stability.

Conversely, the study highlights the intrascleral haptic fixation technique as the most time-efficient option, while noting that conventional sutured fixation is associated with a statistically significant increase in postoperative astigmatism, likely due to suture-related factors such as uneven tension or loosening.

Limitations
The authors acknowledge several limitations, including the retrospective nature of the study which may introduce selection bias, the relatively small sample size of the intrascleral haptic group (n=18) which may limit statistical power, and a follow-up period limited to six months, which precludes the assessment of late-term complications such as suture degradation or late IOL dislocation. Additionally, the techniques were adopted during different periods, potentially introducing calendar-time effects.

Technical Summary: Comparative Outcomes of Scleral Fixation Techniques for Secondary IOL Implantation

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