Watch for signs of zonulopathy at start of cataract surgery
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A careful slit lamp microscope examination of the eye during the preoperative consultation can pick up most cases of compromised zonular support.
The most common signs would be those related to pseudoexfoliation syndrome, such as deposition of fibrillar material on the lens capsule and iris. Traumatic zonulopathy may show as an excessively deep anterior chamber, phacodonesis, or a gap between the iris and the anterior lens capsule. In this case, however, the preoperative examination appeared completely normal.
The first indication of zonulopathy was wrinkling of the anterior lens capsule upon attempted capsulorrhexis creation (Figure 1). The zonular support was so weak that it was difficult to puncture the lens capsule initially. Once the capsulorrhexis was completed, it was evident that the nucleus exhibited too much mobility to make intracapsular surgery safe. Care was taken to hydrodissect and then hydrodelineate the lens nucleus and bring it up out of the capsular bag. The nucleus was removed without trouble, but when it came time to aspirate the epinuclear shell, the surgeon was surprised to see a crescent-shaped bright red reflex in one quadrant (Figure 2).
Source: Uday Devgan, MD
This area of bright red reflex indicated the absence of zonular support for that quadrant instead of the global zonular laxity that was expected. Using extra viscoelastic, the remaining lens epinucleus and cortex were separated from the capsular bag and then gently aspirated using the irrigation/aspiration probe. The flow settings were decreased to 20 cc/minute in order to avoid washing away the protective viscoelastic. Once most of the lens cortex was removed, the capsular bag was inflated with a cohesive viscoelastic, and a capsular tension ring was placed into the capsular bag (Figure 3) to provide equatorial support. This helps to bolster the area of the capsular bag that is missing zonular attachments, but it can trap cortex in the bag and make cortical cleanup more challenging.
If this patient were scheduled for a monofocal non-toric IOL, then a three-piece design may provide the most options for placement. It could be placed entirely within the capsular bag, entirely within the sulcus, or optic captured with the haptics in the sulcus and the optic behind the capsulorrhexis. In our case, however, the patient needed a toric IOL to address 2 D of preexisting corneal astigmatism, and he also elected for an extended depth of focus (EDOF) design. This IOL type is only available in a single-piece acrylic platform that must be placed within the capsular bag. Additionally, the toric axis of the IOL must be accurately aligned with the steep corneal astigmatic axis, and the central EDOF beam-shaping element must be placed in the patient’s visual and pupillary axis.
Care was taken to carefully load and inject this IOL into the capsular bag. It was then dialed into position using the chopper without placing stress on the capsular bag. Finally, it was appropriately aligned and centered at the end of the case, and it remained that way in the postop period (Figure 4). The patient recovered excellent vision and was so pleased that he requested the same surgery for his second eye.
For the second eye, we had the experience of knowing what happened with the first eye. If there was prior trauma such as an airbag injury to the face, then we may expect the same zonulopathy for the second eye. If there was no prior injury, then there is a question about a congenital weakness of the tissues that could be present in both eyes. Fortunately, the second eye surgery was uneventful and displayed no zonulopathy.
We cannot always predict the challenges that we will face during the cataract surgery even if we do an extensive and detailed preoperative examination. Sometimes the only way to detect zonulopathy is to start the surgery and touch the tissues. By picking up on the subtle clue of capsular wrinkling during capsulorrhexis creation, we were on the lookout for zonular issues. Then, when the crescent-shaped red reflex presented, we realized that a quadrant of zonular support was missing and that a different technique and a capsular tension ring would be needed. Surgeons do not like surprises, but using a stepwise approach, we are able to handle the challenges that each case brings.
See full video of this case at cataractcoach.com.
- For more information:
- Uday Devgan, MD, is in private practice at Devgan Eye Surgery, Chief of Ophthalmology at Olive View UCLA Medical Center and Clinical Professor of Ophthalmology at the Jules Stein Eye Institute, UCLA School of Medicine. He can be reached at 11600 Wilshire Blvd. #200, Los Angeles, CA 90025; email: devgan@gmail.com; website: www.CataractCoach.com.
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