Managing posterior capsular opacification
Fourth in a series of the top 10 reasons for poor premium IOL outcomes and how to remedy them.
Now that you have mastered the fine art of managing patient expectations, the premium preoperative evaluation and astigmatism, the next critical step to a happy patient is knowing when and how to manage posterior capsular opacification.
Despite the advances in IOL technology — standard or premium, monofocal, accommodating or multifocal, MICS or dual optic, square edge or not — PCO still occurs and can be quite menacing to the visual outcome, especially in patients with high expectations and premium IOLs. However, due to the great efforts of Daniele Aron Rosa, MD, the YAG laser has become one of the great ophthalmic advances in disruptive technology of PCO.
Development of PCO
PCO development is typically multifactorial due to poor cortical clean-up, retained lens epithelial cells at the lens equator and/or under the anterior capsule, and/or an irregular non-centered, non-overlapping anterior capsulorrhexis 360° over the IOL optic. At a recent meeting, Samuel Masket, MD, presented reduced PCO rates, with particular attention to anterior subcapsular polishing of lens epithelial cells.
The late David J. Apple, MD, reiterated that despite the popular concept of “no space, no cells” leading to no lens epithelial cells, the newer, thinner and more flexible IOLs may not be able to withstand the distortion from posterior capsular shrinkage, leading to possible lens decentration. The Z syndrome characteristic of the older accommodating Crystalens AT45 (Bausch + Lomb) is a classic example of the latter problem, often necessitating early YAG capsulotomy to avoid induced astigmatism and/or loss of the premium visual outcome. (Editor’s note: This problem has not been reported with the newer Crystalens HD.)
Before capsulotomy, it remains important to perform a good dilated retinal exam, often in conjunction with optical coherence tomography to ensure the reduced vision is not due to macular pathology rather than PCO. The toughest challenge, especially with premium IOLs, is the timing for YAG capsulotomy. Obviously if a Z syndrome is present, the sooner the better.
With regard to multifocal IOLs, if a patient complains of glare and/or halos and has residual astigmatism and mild PCO, the approach becomes trickier. If the YAG is done too soon and the patient’s complaints persist despite astigmatism correction, the IOL may have to be removed in the face of an open posterior capsule. On the other hand, refractive error changes, although small, can occur after YAG capsulotomy, and the desire to correct them after the YAG will hopefully limit the number of enhancements needed with laser vision correction and/or limbal relaxing incisions to just one time.
My preference in milder PCO is to treat the refractive error first and only if it has stabilized before YAG capsulotomy. I find it easier to perform a second refractive enhancement than exchange an IOL with an open posterior capsule in the worst-case scenario. In moderate or worse PCO, the decision is easier because the PCO typically is the main cause for visual complaint. It is also important to look at angle kappa readings (easily done with the Marco OPD-Scan III) before capsulotomy if not measured before cataract surgery. In the presence of mild PCO, a high angle kappa (typically higher than 0.4 mm), a multifocal IOL and a complaining patient, I tend to exchange the IOL because YAG capsulotomy treatment will not solve the multifocal optic confusion. Conversely, with an aspheric toric or aspheric accommodating IOL and a high angle kappa, YAG capsulotomy will most likely solve the problem.
The last challenge seen with PCO is whether anti-inflammatory medication is important. The intraocular debris from a YAG-disrupted capsulotomy can be inflammatory and potentially migrate to the angle, where it can cause trabeculitis and, in the worst case, sudden and/or significant IOP spikes. If a patient is high risk, such as someone who has a history of uveitis, cystoid macular edema in the fellow eye or diabetics even without background diabetic retinopathy, cystoid macular edema after YAG capsulotomy becomes a potential additional visual risk, especially in the premium IOL patient. The use of topical steroids, such as Lotemax (loteprednol etabonate ophthalmic suspension 0.5%, Bausch + Lomb), with its lower risk of IOP elevation while controlling inflammation, and/or a topical nonsteroidal such as Bromday (bromfenac ophthalmic solution 0.09%, Ista Pharmaceuticals), with its convenient once-a-day dosing, might be good preventive options for the premium IOL patient if a YAG capsulotomy is needed.
In the end, premium IOL patients tend to voice their vision complaints sooner than standard IOL patients if PCO exists, be it a function of the more complex optics of their IOLs or because they have paid a considerable amount for their “advanced” IOL technology.
Stay tuned for managing cystoid macular edema in terms of prophylaxis or its development in the premium IOL patient in the November/December issue.
Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Ave., Suite L, Lake Villa, IL 60046; 847-356-0700; fax: 847-589-0609; email: firstname.lastname@example.org.
Disclosure: Dr. Jackson is on the speakers bureaus for Ista, Bausch + Lomb and AMO.