Capsule-Preserving Intraocular Lens Intrascleral Fixation for Zonular Weakness: Clinical Outcomes and Comparative Analysis

Mutsuko Kato, Yuri Kumashiro, Iori Masatani, Eizo Tanaka, Naohiro Ide, Kanazu Ariyasu Department of Ophthalmology, Japan Red Cross Okayama Hospital, Okayama, Okayama-Prefecture, JapanCorrespondence: Mutsuko Kato, Department of Ophthalmology, Japan Red Cross Okayama Hospital, 2-1-1 Aoe, Kita-ward, Okayama, 700-8607, Japan, Tel +81 86 222 8811, Fax +81 86 222 8841, Email [email protected]: To compare postoperative outcomes of haptic fixation sites, single versus dual haptics, in capsule-preserving intraocular lens (IOL) intrascleral fixation for zonular weakness.Patients and Methods: This retrospective study analyzed 88 eyes (65 patients) with zonular weakness and at least two additional risk factors for IOL dislocation. Conducted at a single center from May 2019 to July 2023, the study followed patients for 6– 56 months (mean: 26.5± 16.0 months). Fixation methods included single or dual haptics, selected based on the operator’s subjective assessment of zonular weakness and patient age. Initially, scleral tunnel-style was used, transitioning to flange-style in October 2021. Outcomes assessed included IOL tilt, decentration, refractive error, and complications.Results: Final assessments showed an average IOL tilt of 6.54± 3.14° and decentration of 0.60± 0.36mm. Refractive error at six months post-surgery averaged − 0.33± 0.99D. Dual fixation resulted in greater myopic shifts than single fixation (− 0.79± 0.93D vs − 0.16± 0.96D, p< 0.01), especially tunnel-dual fixation compared to tunnel-single fixation (− 1.31± 0.61D vs − 0.25± 0.89D, p< 0.001) and tunnel-dual fixation compared to flange-dual fixation (− 1.31± 0.61D vs − 0.17± 0.88D, p=0.001). Large IOL tilts (> 10°) occurred in six eyes (6.8%), all with tunnel style, with a refractive error of − 0.59± 0.78D; not statistically significant, but a correlation was observed between tilt and refractive error (R²=0.851, p=0.0176). Large IOL decentration (> 1mm) occurred in 12 eyes (13.6%), with a significant myopic shift of − 1.01± 0.93D. Capsule damage was noted in 15.9% of cases, vitreous prolapse was infrequent (4.5%), and no cases had iris capture or severe retinal complications.Conclusion: Despite the risk of capsule damage, this method, which preserves the capsule and avoids posterior segment surgery, appears viable for cases with significant zonular weakness and anticipated progression, without iris capture or retinal complications. Improving the T-style or adopting F-style, particularly FD-fixation, may help prevent tilt and decentration, reduce refractive errors, and improve postoperative visual function.Keywords: zonular weakness, capsule-preserving, single/dual-flange/tunnel IOL intrascleral fixation, optic capture, tilting, decentration