Surgical indications and outcomes of intraocular lens exchange surgery: A 5-year retrospective review

INTRODUCTION

Intraocular lens (IOL) exchange is a challenging but essential surgical procedure primarily performed to address complications related to primary IOL implantation.^[1,2] As cataract surgery remains one of the most frequently performed surgeries worldwide, the number of patients requiring IOL exchange due to complications or dissatisfaction continues to grow.^[3] Current indications for IOL exchange include lens dislocation, optical aberrations and multifocal IOL intolerance, among other vision-related complaints.^[4] While advances in IOL technology have expanded the range of achievable visual outcomes, they have also introduced new challenges related to patient satisfaction and lens stability.^[5-7]

The decision to perform an IOL exchange is often complex and requires a thorough assessment of visual symptoms, lens position and patient expectations.^[8] Moreover, the surgical techniques used for IOL exchange vary widely depending on the underlying indication, lens type and anatomical considerations. Postoperative visual outcomes and complication rates are influenced by factors such as the type of secondary IOL implanted, the surgical approach and pre-existing ocular comorbidities.^[9]

In 2016, Davies and Pineda published a single-surgeon series of 109 eyes undergoing IOL exchange. The present study is a follow-up on this prior work by extending the case series through December 2024 and incorporating modern IOL designs and advanced fixation techniques to reassess indications, visual outcomes and complication rates. Despite IOL exchange serving as a useful intervention in complex cases of IOL-related complications, there is limited data on long-term visual outcomes and complication profiles. In addition, there is a need for more comprehensive data on how evolving IOL designs impact the frequency and nature of exchange procedures. Therefore, this study evaluates the indications, surgical techniques, visual outcomes and complications associated with IOL exchange in a large cohort over 5 years, with the goal of optimising patient selection and improving procedural safety and efficacy.

MATERIALS AND METHODS

RESULTS

IOL exchange was performed in 195 eyes of 172 patients with a mean age of 66.4 ± 10.6 years [Table 1]. The mean interval between primary cataract surgery and IOL exchange was 6.6 ± 10.9 years (median 2.6 years, range 2 days–37.2 years). The average follow-up duration after IOL exchange was 14.6 ± 14.1 months (range 1 month–4.6 years). The most common pre-existing intraocular conditions included glaucoma (34.3%, n = 67), dry eye disease (25.6%, n = 50), anterior uveitis (13.8%, n = 27), CME (11.8%, n = 23) and ocular trauma (11.3%, n = 22) [Table 2]. Mean pre-operative BCVA was 0.48 ± 0.57 LogMAR (Snellen equivalent 20/61).

IOL dislocation was the most frequent indication for IOL exchange (32.3%, n = 63). Across these cases, lens-level documentation showed a heterogeneous model distribution without a single clear predominance. This was followed by MFIOL intolerance (14.4%, n = 28) and dysphotopsias. Dysphotopsias accounted for 13.3% (n = 26) of cases and were characterised as positive (n = 23), negative (n = 2) or chromatic (n = 1). Residual refractive error accounted for 10.8% (n = 21) of cases, and EDOF intolerance accounted for 7.2% (n = 14) of cases [Table 3].

Monofocal IOLs were the most frequently explanted IOLs (51.3%, n = 100), followed by multifocal (19.0%, n = 37), EDOF (9.2%, n = 18) and accommodative lenses (3.1%, n = 6). The type of explanted lens was unknown or undocumented in 16.9% (n = 33) of cases due to incomplete external surgeon records. Detailed explanted IOL data are shown in Supplementary Table S1. After IOL explantation, most eyes underwent monofocal IOL implantation (93.8%, n = 183), with the Zeiss CT Lucia 602 being the most common secondary IOL (34.3%, n = 67, [Supplementary Table S2]). The secondary IOL was implanted into the capsular bag in 71 eyes (34.1%). Other techniques for secondary IOL implantation included scleral fixation through the Yamane technique (26.9%, n = 56), into the ciliary sulcus with optic capture (17.8%, n = 37) or without optic capture (13.5%, n = 28) and ACIOL placement (2.4%, n = 5, [ Table 4]).

At 1-month postoperatively, the mean BCVA was 0.33 ± 0.51 LogMAR (Snellen equivalent 20/43), which was a significant improvement compared to mean pre-operative BCVA (p = 0.04, [Figure 1]). BCVA of 20/40 or better was achieved in with 71.3% of eyes. A decline of two or more lines occurred in 14 eyes (7.2%) and was primarily related to early post-operative complications; in 12 eyes (85.7%), this decline had resolved by post-operative month 3. Of the eyes not achieving 20/40 or better visual acuity, ocular pathology unrelated to the intraocular exchange surgery was identified in 32 eyes (57.0%). In terms of refractive outcomes, 60.0% of eyes achieved a spherical equivalent within ±0.25 D of the intended target, and 86.5% were within ±0.50 D [Figure 2].

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Figure 1: Pre and post-operative visual acuity distribution.

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Figure 2: Distribution of post-operative spherical equivalent error relative to the intended target.

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Subgroup analysis of the 55 eyes (45 patients) that underwent EDOF or MFIOL removal and lens exchange showed that the median time from initial implantation to exchange was 16.8 months. The majority of secondary lenses implanted after MFIOL or EDOF removal were monofocal (90.9%), with 9.1% receiving EDOF lenses. At 1 month postoperatively, 92.7% achieved BCVA of 20/40 or better, while 7.3% experienced a loss of two or more lines of vision. Notably, dysphotopsia and intolerance indications were observed across multiple MFIOL/EDOF designs, without statistical significance for any single model.

Post-operative complications included CME (7.2%, n = 14) and elevated Intraocular pressure (IOP) (4.7%, n = 9). Retinal detachment occurred in one eye at post-operative week 6, although this patient had several pre-existing risk factors including pathologic myopia and tractional epiretinal membrane. Two patients underwent subsequent IOL exchange to correct the significant tilt of the initial IOL, which could not be corrected with repositioning, and to address a disinserted haptic from the optic that resulted in unstable fixation [Table 5]. Other post-operative surgical interventions included IOL repositioning (2.6%, n = 5), wound revision requiring surgery (1.0%, n = 2) and hyphaema requiring anterior chamber washout (1.0%, n = 2). Residual refractive error was treated with subsequent limbal relaxing incision (0.5%, n = 1) or Laser-assisted in situ keratomileusis (LASIK) (0.5%, n = 1). Nd: YAG laser capsulotomy was performed in 49 patients (25.1%) for posterior capsule opacification (PCO). PCO causality could not be determined as it can be a consequence of the initial cataract surgery or after IOL exchange; accordingly, PCO requiring Nd: YAG was recorded as an outcome event without attribution to either procedure.

DISCUSSION

This study provides a comprehensive analysis of IOL exchange procedures in a large cohort of 195 eyes, making it one of the largest analyses of IOL exchange outcomes in a tertiary care setting. Compared with our earlier single-surgeon series of 109 eyes reported in 2016, the present cohort captures a broader, more contemporary spectrum of exchange surgery, with similar overall indication patterns and early visual outcomes.^[10] In-the-bag IOL dislocation remained the leading indication for IOL exchange, occurring in 27.5% of cases in our study versus 32.3% in the 2016 study.^[11]

Patient dissatisfaction with multifocal IOLs accounted for 14.4% of exchanges in the current cohort (vs. 18.3% previously), while exchanges of EDOF lenses comprised 7.2% of indications, underscoring the expanding spectrum of functional dissatisfaction with premium optics.^[12,13]Given advancements in IOL technology, managing patient expectations regarding potential side effects remains essential to reduce the risk of dissatisfaction. The average interval from cataract surgery to exchange has lengthened (80 months vs. 55 months previously), likely reflecting higher proportion of late dislocations from progressive zonular compromise and the tendency to exhaust non-surgical measures including spectacle correction and refractive enhancement before electing for IOL exchange.

Surgical practice has also evolved over time. While intracapsular exchange is still preferred when support is adequate (36.4% vs. 43.1%), nearly onethird of our contemporary cases employ scleral fixation through the Yamane technique. The Yamane technique was not used in our prior cohort of cases performed between 2010 and 2015, indicating growing confidence in sutureless fixation for compromised capsules. This shift coincides with greater refractive accuracy, with 86.5% of eyes now landing within ±0.50 D of target versus 70% reported previously. It was also associated with a modest drop in CME (7.2% vs. 10.1%), while PCO requiring Nd: YAG increased (25.1% vs. 13.8%), likely reflecting both a higher propensity for PCO in complex cases and a lower clinical threshold for laser capsulotomy in our tertiary setting to expedite visual rehabilitation. Given the prolonged interval between cataract surgery and IOL exchange in this series, the occurrence of PCO is not unexpected and was effectively managed in most cases with Nd: YAG laser capsulotomy. Visual acuity gains remain comparable (71.3% vs. 78.9% achieving 20/40 or better), reinforcing that modern exchange surgery continues to deliver reliable functional rehabilitation while addressing a progressively diversified set of indications. Patients with residual visual acuity deficits were driven primarily by unrelated ocular disease and not due to the lens exchange procedure.

Monofocal IOLs were the most frequently explanted lenses (51.3%), likely reflecting the widespread use of monofocal IOLs during the period when the primary surgeries were performed. The most commonly explanted models were the Tecnis DIB00 (Johnson and Johnson, New Jersey, USA) and PanOptix TFNT00 (Alcon, Geneva, Switzerland), followed closely by Tecnis ZCB00 (Johnson and Johnson, New Jersey, USA) and AcrySof SN60WF (Alcon, Geneva, Switzerland), consistent with the fact that these lens models are among the most frequently implanted globally.^[14] After IOL explantation, nearly all eyes underwent monofocal IOL implantation, with the Zeiss CT Lucia 602 being the most common secondary IOL.

Post-operative complications were uncommon in our cohort, with CME and elevated intraocular pressure being the most frequently observed. These complications are known risks associated with IOL exchange, particularly in eyes with pre-existing uveitis or glaucoma.^[15] One case of retinal detachment was recorded, occurring 6 weeks postoperatively in a patient with pre-existing vitreoretinal pathology. Although a rare event, this emphasises the need for thorough pre-operative evaluation, especially in patients with complex ocular histories or known risk factors for vitreoretinal complications.^[16]

Limitations of our study include its retrospective nature, which introduces potential selection bias and incomplete data. Given the retrospective design, post-operative follow-up and ancillary testing were not standardised across all cases, which may have limited the detection of some post-operative findings. The heterogeneity in surgical techniques and lens choices included also introduces variability, making direct comparisons between techniques challenging. As a tertiary referral series, the cohort likely overrepresents complex cases. All exchanges were performed by a single surgeon at one hospital, introducing surgeon-preference bias while maximising procedural and post-operative standardisation. Follow-up was variable which limits detection of late complications; however, all eyes were observed for at least 1 month and 50% for 6 months or longer, permitting analysis of early and intermediate outcomes.

These findings should be interpreted as early post-operative outcomes, and longer follow-up is needed to more fully characterise later complications and the durability of results. Future studies may be strengthened by extending the minimum follow-up period, particularly important for assessing cases with scleral-fixated IOLs and including patient-reported outcomes for a more complete assessment of visual satisfaction. Despite its limitations, this study remains highly valuable due to its large sample size, comprehensive data collection and focus on both standard and advanced IOL exchange scenarios.

CONCLUSION

In summary, our study underscores the effectiveness of IOL exchange in addressing complications related to primary IOL implantation, particularly in improving visual acuity for the majority of patients. However, the variability in indications and lens types highlights the importance of individualised patient assessment and a careful surgical approach. Future research should focus on identifying risk factors for poor visual outcomes after IOL exchange and exploring advancements in IOL design to reduce the necessity for exchange. In addition, long-term follow-up studies are warranted to better understand the durability of secondary IOLs and the stability of different fixation techniques. This study contributes to the growing body of evidence supporting the role of IOL exchange in managing complex post-operative cases while emphasising the importance of patient-centred IOL selection and meticulous surgical planning to optimise visual outcomes.