CORRESPONDENCE

Inadvertent Trypan Blue PosteriorCapsule Staining during CataractSurgery

EDITOR:

THEARTICLEBYBURKHOLDERANDASSOCIATES ISAUSEFUL

addition to the literature in that it highlights the relativelyuncommon complication of inadvertent trypan blue stain-ing of the posterior capsule and adds to the list of riskfactors (that includes traumatic cataract and pseudoexfoli-ation) the use of iris hooks.1 We first noted this phenom-enon in the second case we treated, and although it madethe surgery more difficult, the advantage of being able tosee the anterior capsule clearly throughout the surgery faroutweighed the disadvantage of a reduced red reflex.2,3

In our minimalist 1-step technique of trypan blue appli-cation to the anterior capsule, aqueous humor initially isallowed to exit the anterior chamber, which consequentlyshallows, and the resulting pupil block confines the dye tothe anterior capsule, when a moderate volume of dye isinstilled.4,5 We believe that this is a critical step in dyeapplication. An ophthalmic viscosurgical device then isused to flush dye-stained aqueous from the anteriorchamber, circumventing the need for anterior chamberwashout.

It would be useful to know the precise method of insertionof iris hooks because this does not seem to be described in thearticle. When iris hooks first arrived in Australia, there wassome departmental discussion regarding how they shouldbest be applied. The consensus was that hook ports shouldbemade with a 15-degree blade just posterior and perpendic-ular to the surface of the surgical limbus, care being taken notto penetrate the iris.6 This sometimes makes passage of thehooks to the pupil margin more difficult because the hookshaft now needs to bend to be in the iris plain; this passagecan be facilitated by a Sinskey hook. However, the resultantvector forces are such that the iris is pulled both peripherallyand also posteriorly, rather than anteriorly. In this way, theiris remains opposed to the anterior capsule, eliminating orat least reducing the flow of fluid from the anterior chamberinto the posterior segment. By magnifying the images inFigure 1 of the article, it appears that the hook ports havebeen made in a more horizontal direction with a consequentlifting of the iris off the anterior capsule plain. This wouldfacilitate the passage of dye under the iris and into the poste-rior segment, thereby facilitating staining of the posteriorcapsule. This configuration also can result in shallowing ofthe anterior chamber, because during phacoemulsification,infusate can force the iris anteriorly. This is particularly prob-lematic in cases where there is zonular dialysis and the

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anterior vitreous can bemore directly hydrated. Furthermore,in an age of phacoemulsification chopping and femtosecondnucleus fragmentation, this configuration could facilitate thetransport of small nuclear fragments into the posteriorchamber and beyond. This method of vertical incisions foriris hook insertion also is useful in dealing with floppy irides,because the vector forces help to push the iris posteriorly.If, in the cases reported, iris hooks were inserted horizon-

tally, then by altering the insertion technique, this compli-cation of capsular dye use can be rendered even moreuncommon. Furthermore, the technique of vertical hookinsertion has other advantages that add an extra safetyfactor to managing small pupil cases.

MINAS T. CORONEO

Sydney, Australia

CONFLICT OF INTEREST DISCLOSURES: ALL AUTHORShave completed and submitted the ICMJE Form for Disclosure of PotentialConflicts of Interest and the following were reported. Dr Coroneo reportsroyalties from Dutch Ophthalmic Research Center International B.V.during the conduct of the study. In addition, Dr Coroneo has a patent,Methods for Visualizing the Anterior Lens Capsule of the Human Eye,United States patent 6 367 480, April 9, 2002, with royalties paid to theauthor, and a patent, Ophthalmic Methods and Uses, United StatesPatent 6 372 449, April 16, 2002, with royalties paid to the author. Theauthor worked in the past as a consultant to Dutch Ophthalmic ResearchCenter International B.V. and continues to do so on an ad hoc basis.

REFERENCES

1. Burkholder BM, Srikumaran D, Nanji A, et al. Inadvertenttrypan blue posterior capsule staining during cataract surgery.Am J Ophthalmol 2013;155(4):625–628.

2. Coroneo MT, inventor. Methods for visualizing the anteriorlens capsule of the human eye. U.S. Patent 6 367 480. April9, 2002.

3. Coroneo M. Retrospective on staining with trypan blue. Cata-ract Refract Surg Today 2005;5(3):49–51.

4. Laureano JS, Coroneo MT. Crystalline lens capsule stainingwith trypan blue. J Cataract Refract Surg 2004;30(10):2046–2049.

5. Coroneo M. Tips for capsular staining. Cataract Refract SurgToday 2007;7(10):63–66.

6. Goldberg I. Flexible iris retraction hooks. Aust N Z J Ophthal-mol 1995;23(4):357.

REPLY

WE THANK DR CORONEO FOR THE COMMENTS AND

interest in our article. We agree that if the posterior capsule

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