New astigmatism after cataract surgery: How to proceed?

Cynthia Matossian, MD, FACS, describes a complex case and seeks advice from her CEDARS/ASPENS colleagues.

Issue: June 25, 2018

ByCynthia Matossian, MD, FACS

Welcome to another edition of CEDARS/ASPENS Debates. CEDARS/ASPENS is a joint society of cornea, cataract and refractive surgery specialists, here to discuss some of the latest hot topics in ophthalmology.

This month, Cynthia Matossian, MD, FACS, presents a case of late-onset postop astigmatism after cataract surgery with extended depth of focus lens implantation. Mitchell A. Jackson, MD, Quentin B. Allen, MD, and John R. Moran, MD, PhD, each offer their unique perspectives on how to manage this case, with Dr. Matossian then revealing what she actually did. We hope you enjoy this discussion.

Kenneth A. Beckman, MD, FACS
OSN CEDARS/ASPENS Debates Editor

This month’s column describes a case of emergent astigmatism approximately 1 year after cataract surgery, the expert advice offered by CEDARS/ASPENS members and an industry consultant, and the eventual resolution of the case.

The case

A 69-year-old male physician underwent uncomplicated cataract surgery, performed by myself, in the dominant right eye in December 2016. Measurements in the right eye before cataract surgery were:

Refraction: –1.75 +1.00 × 162
Manual keratometry: 41.75/43.00 × 170
Marco Nidek OPD II keratometry: 41.87/43.49 × 170

A Tecnis Symfony toric extended depth of focus (ZXT150) IOL +20.50 (Johnson & Johnson Vision) was inserted. The outcome was successful, with an uncorrected distance visual acuity (UCDVA) of 20/20 and no cylinder. The patient’s postoperative vision was stable for 8 months.

The patient returned in August 2017 with a change in vision in the right eye to UCDVA of 20/40. He had mild posterior capsule opacification (PCO). Refraction in the right eye had changed to plano +1.00 × 175, representing an increase in the cylinder in the same axis as before surgery. YAG laser capsulotomy was performed without incident to clear the PCO.

By fall 2017, the patient’s vision in the right eye after multiple refractions and optimization of his ocular surface was –0.25 +1.00 × 180 20/20. Keratometry was repeated and confirmed on multiple visits. Measurements were:

Manual keratometry: 41.87/43.50 × 155
OPD III keratometry: 41.93/43.44 × 165
i-Optics Cassini keratometry: 41.75/43.55 × 174

Axial length was 24.28 mm, with no change on repeat biometry before and after surgery. The retroillumination image on the OPD III showed near perfect alignment (4° difference) between readings before the cataract procedure and after the YAG capsulotomy. The Toric Results Analyzer indicated 0° of rotation were required. The IOL was not tilted.

The question at this point was, “How to proceed?” CEDARS/ASPENS members and other consultants were queried for their expert advice via email, with the patient’s information completely deidentified. Suggestions from these experts included the following, which are edited lightly for clarity and printed with their permission and my grateful acknowledgement.

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Mitchell A. Jackson, MD, Founder/CEO, Jacksoneye, Lake Villa, Illinois

A paired limbal relaxing incision (LRI) will most likely leave the patient with a manifest refraction close to his current spherical equivalent of +0.25 spherical, which should be adequate as the residual consecutive cylinder is definitely a culprit of patient dissatisfaction. I had a similar patient dissatisfied due to a small residual refraction post-YAG capsulotomy, post-ZXT Symfony toric IOL of –1.00 + 0.75 × 55 20/20 correctable. I performed LASIK surgery for her, and she is now delighted. It is amazing what residual cylinder can do with these lenses, so I would do LASIK if the corneal epithelium is optimized for it and corneal topographic mapping/thickness is ideal for such. If the patient has any epithelial basement membrane dystrophy changes, I would prefer PRK over LASIK.

Quentin B. Allen, MD, Florida Vision Institute, Stuart, Florida

This is an interesting case. Been there, done that!

Warren Hill, in personal communication, has noted a tendency for the Abbott Medical Optics (now J&J Vision) platform to have hyperopic shifts over time, and I have seen this as well, possibly due to the anterior offset haptic configuration. I still think the lenses are excellent, and I use all IOL platforms depending on the clinical scenario. However, I aim a little more myopic if implanting a J&J Vision lens (–0.3 D or more), just in case it has a tendency to drift plus. I have seen this in several refractive IOL patients, and it obviously affects near performance, which can lead to more enhancements or, at minimum, unhappy patients.

Given the impact of posterior corneal astigmatism, we now know to try to slightly undercorrect these patients for with-the-rule astigmatism during surgery, but it still takes a leap of faith. With against-the-rule (ATR) cases, the ORA system (Alcon) usually confirms the excess ATR astigmatism and the need for a higher toricity lens; nonetheless, we all still sometimes end up exactly with this case.

For this patient, I would favor a manual LRI on his refractive axis, with depth adjustment based on his central corneal thickness (CCT) and the NAPA nomogram.

I would do 40° arcs with a diamond blade just inside the vascular arcades at CCT plus 50 µm. If you have a Pentacam (Oculus), you can more accurately assess the peripheral corneal thickness. The online LRI calculator indicates paired 40° arcs, which in my experience would be about right (just ignore the LRI depth recommendation). The patient should end up +0.25, as Dr. Jackson said. For a dominant eye Symfony, this would be a great outcome for most patients and less risky than PRK or LASIK in this 69-year-old patient.

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If you decide to perform laser vision correction, I have done both PRK and LASIK, but I prefer LASIK with this refraction unless anatomy is challenging.

John R. Moran, MD, PhD, Moran Research and Consulting, Houston

Based on pre- and postoperative OPD scans, the mean corneal power increased 0.38 D. The corneal astigmatism increased by 0.15 D and rotated clockwise by 2°. This was caused by increases in power of 0.31 D and 0.45 D along meridians 164° and 74°, respectively. Although we do not have topography after the primary procedure but before the refractive change, it seems unlikely corneal changes are responsible for the ametropia. In addition, the small changes in the cornea point to exquisite surgical technique.

I think the IOL probably rotated and shifted posteriorly just enough to cause problems as a result of capsular contraction and PCO. I would not attempt to rotate the IOL after posterior capsulotomy. I would consider either making a four-cut radial anterior capsulotomy to relieve stress on the IOL or, preferably, perform PRK. I feel LRI is not predictable enough for this situation.

Resolution of case

After explaining the various options to the patient, I proceeded with a manual LRI in the right eye on Jan. 10, 2018. Four weeks later, his UCDVA was 20/20 again. His right eye refraction was plano +0.25 × 175, and the patient was very happy again.

For more information:
Quentin B. Allen, MD, can be reached at Florida Vision Institute, 1050 SE Monterey Road, Suite 104, Stuart, FL 34994; email: q_allen@yahoo.com.
Mitchell A. Jackson, MD, can be reached at Jacksoneye, 300 N. Milwaukee Ave., Suite L, Lake Villa, IL 60046; email: mjlaserdoc@msn.com.
Cynthia Matossian, MD, FACS, can be reached at Matossian Eye Associates; email: cmatossian@matossianeye.com.
John R. Moran, MD, PhD, can be reached at Moran Research and Consulting Inc., 5252 Westchester St., Suite 114, Houston, TX 77005; email: jmoran@previze.com.

Disclosures: Allen reports financial disclosures for Alcon Surgical, Bausch + Lomb, Omeros and Allergan. Jackson reports he is a speaker for Johnson & Johnson. Matossian reports she is a consultant to J&J and Marco. Moran reports he is a consultant to J&J Vision and Staar Surgical Company.