Suturing microscopic wound leaks can avoid myopic shifts

A surgeon explains how suturing Seidel positive Crystalens wounds can create better postoperative results.

John A. Hovanesian

A number of surgeons have noticed that myopic shifts can occur about 1 month after surgery with the Bausch & Lomb Crystalens.

These shifts are usually less than 1 D, but they cause enough degradation of distance vision to require enhancement procedures in the majority of patients. Laser enhancements or piggyback lens implants can treat these shifts, but how do we avoid them?

Capsulorrhexis size

Some have suggested that capsulorrhexis size and shape matter. Jack A. Singer, MD, and others have suggested that a 5 mm X 8 mm oval capsulorrhexis may avoid refractive shifts. Yet many surgeons use a variety of capsulorrhexis sizes, ranging from 5 mm to nearly 8 mm, and still experience occasional myopic shifts. A group of Crystalens users is currently looking into the relationship between capsulorrhexis size and outcome and will provide updates on its findings.

Cycloplegia

Others have suggested that the use of cycloplegic drops during and after surgery plays a part. For 3 years, my study group practice, Harvard Eye Associates in southern Orange County, Calif., used atropine during and after surgery. After discontinuing this part of our regimen, we saw no increase in myopic shifts with the Crystalens SE, AT-50 or HD.

Pupil size

Some surgeons think the 3-µm elevation in the central 2 mm of the Crystalens HD optic is responsible for this shift, especially among patients with small pupils. Again, a study is under way to examine this correlation.

Retained cortex, lens epithelial cells

It is possible that small amounts of retained cortex in the peripheral lens capsule may cause forward-shifting of the lens position and myopia. Retained lens epithelial cells may also contribute to the process. For this reason, especially careful cortical cleanout and vacuuming of the posterior aspect of the anterior capsule are worthwhile investments of time and effort in Crystalens surgery.

Wound leaks

One factor certainly makes a difference in myopic shifts: small wound leaks at the end of surgery. This idea had been suggested by a number of surgeons, but no formal studies had been performed.

To test the association between wound leaks and myopic shifts with the Crystalens, our center performed a controlled, retrospective study that was presented as a poster at the 2008 American Academy of Ophthalmology meeting. For several months, we had been routinely performing a Seidel test at the end of cataract surgery. Initially our surgeons were surprised to find small wound leaks, not detectable without a Seidel test, in about one-third of patients. Retrospectively, we reviewed 100 charts of Crystalens patients – 50 who had Seidel negative wounds and 50 with small leaks, detectable only with a Seidel test. Neither group had received sutures. Comparing 1-month postoperative refractions to target, we learned that leaking wounds had an average refractive “surprise,” compared with target refraction, 0.54 D more myopic than those that were Seidel negative at the time of surgery.

It is now our standard of practice to suture any Seidel positive Crystalens wounds. Newer, better methods of sealing incisions may allow us to use a technology even better than suture in the future.

• John A. Hovanesian, MD, FACS, can be reached at Harvard Eye Associates, 24401 Calle De La Louisa, Suite 300, Laguna Hills, CA 92653; 949-951-2020; fax: 949-380-7856; e-mail: drhovanesian@harvardeye.com. Dr. Hovanesian is a consultant for Bausch & Lomb.