Intraocular Lens Exchange and Secondary Intraocular Lens Placement

Key Points

• The most common indications for intraocular lens (IOL) removal and exchange include IOL decentration, refractive error, and dysphotopsia.

• Secondary IOL implantation is often required for patients with a history of aphakia after complex cataract surgery or trauma.

• New techniques and technologies have made secondary IOL implantation safer with better visual outcomes.

• Suture-less scleral-fixated IOLs are the newest and most promising techniques but more research with long-term follow-up results is still needed.

• Surgeons should consider the advantages and disadvantages of these techniques in patients with a diverse array of pathology and perform only the procedures they are comfortable with.

Introduction

Ideally, cataract extraction and placement of an intraocular lens (IOL) is performed in one operation, and the IOL is placed within the capsular bag. However, complicated extracapsular surgery, trauma, poor refractive outcome, or other patient factors may necessitate IOL removal, exchange, or secondary IOL placement. Historically, secondary IOL options were thought to have higher complication rates, which may include corneal edema, uncertain refractive outcome, cystoid macular edema (CME), bleeding, or choroidal detachment, depending on the technique. New IOL extraction techniques, IOL fixation techniques, IOL designs, and sutures have expanded dramatically over the last decade. With these innovations, patients can have excellent anatomic and refractive outcomes after IOL exchange and secondary IOL implantation with minimal complications. This chapter reviews indications, advantages, and challenges of IOL exchange and the most common and most promising IOL fixation options.

This chapter will primarily cover the following:

• Standard capsular-bag-fixated or sulcus-fixated posterior chamber (PC) lenses

• Scleral-fixated PC lenses

• Iris-fixated IOLs

• Anterior chamber (AC) lenses

Indications

There is a wide range of indications for removal of an IOL and placement of a secondary IOL. Many patients who require secondary IOLs have extensive damage to anterior segment structures or have history of trauma or posterior segment abnormalities. The indication for surgery, ocular comorbidities, and medical comorbidities will certainly affect the choice of IOL and its placement. IOL exchange and in-the-bag secondary placement may be possible in patients with an intact capsule. However, this is rare in patients with complex ocular histories. Additionally, removal of the original IOL may result in loss of capsular support, and capsule-fixated implantation may not be possible. As always, discussion with patients about their visual goals and the risks for surgery is necessary to tailor surgical decision making.

Patient Comorbidities

Numerous pathologies can lead to the final common pathway of aphakia or need for IOL exchange.

• Progressive zonulopathies

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    Pseudoexfoliation

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    Retinitis pigmentosa

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    Pigment dispersion syndrome

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    Marfan’s syndrome or Ehlers Danlos syndrome

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    Uveitis

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    High myopia

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    Prior vitreoretinal surgeries

• Trauma

• Prior pars plana lensectomy (e.g., for complex anterior loop traction in RD)

Intraoperative Complications During Phacoemulsification

Disruption of the capsular bag during cataract surgery may limit IOL placement options. The first step is to assess the remaining capsular support structures.

• Small, round, posterior ruptures in the posterior capsule or ones that can be converted by posterior capsulorrhexis to a curvilinear opening may still allow for in-the-bag placement of an IOL.

• Larger or peripheral breaks in the posterior capsule risk subsequent IOL dislocation posteriorly into the vitreous cavity. In these cases, sulcus placement of an IOL with or without optic capture may be an option.

• If there is a question about anterior capsular integrity, other options such as scleral-fixated IOLs or, less preferably, iris-fixated or anterior-chamber IOLs can be considered.

• If primary placement of an IOL is not safe or the cataract surgeon does not have either the tools needed or requisite skill set for the best available IOL option, aphakia with subsequent secondary IOL placement is also very reasonable.

Postcataract Surgery Complications

Common indications that may necessitate IOL removal, repositioning, or exchange include the following:

• IOL malposition, subluxation, or dislocation

• Uveitis-glaucoma-hyphema (UGH) syndrome

• Pseudophakic or aphakic bullous keratopathy

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    This may necessitate concomitant corneal transplantation.

Patient Dissatisfaction

In this age of refractive cataract surgery, unacceptable refractive or optical outcomes may precipitate IOL exchange.

• Refractive surprises:

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    Hyperopic

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    Myopic

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    Astigmatic

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    Presbyopia

• Positive dysphotopsias:

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    Glare

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    Halos

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    Starbursts

• Negative dysphotopsias

Dysphotopsias are more common with (but not exclusive to) multifocal intraocular lenses (MFIOLs). These patients may complain of limited quality of vision, reduced sharpness, or visual aberrations. In one study of 43 eyes with unwanted visual symptoms after MFIOL implantation, 7% ultimately required IOL exchange, although this study was with the older generation of multifocal IOLs. IOL exchange of multifocal lenses in current cohorts is probably less than 1% of all MFIOLs implanted. Sometimes we now even see patients who choose to have an IOL exchange from a monofocal IOL to a multifocal IOL when the surprise of presbyopia is greater than anticipated. Accordingly, IOL exchange of a well-placed in-the-bag posterior-chamber intraocular lens (PC-IOL) is not uncommon.

Patient Population

Eye Examination

It is important to perform a careful eye examination to rule out other ocular pathology that could limit visual potential and to discuss these findings with the patient. Prior surgeries such as previous glaucoma procedures and presence of conjunctival scarring may affect IOL placement and scleral fixation. Examination of the anterior segment should focus particular attention on:

• Location of IOL

• Type of IOL (one-piece, three-piece, etc.)

• Capsular remains (if any)

• Zonular integrity

• Corneal scarring or edema

• Vitreous in the anterior chamber

• Iris anatomy