Posterior capsule tears have been described during various steps of the phacoemulsification procedure. Most occur at the time of phacoemulsification or cortex aspiration when the tip of the phaco probe accidentally hits and ruptures the posterior capsule.1 To the best of our knowledge, there have been no reports of an intraocular lens (IOL) injector or the lens tip itself causing posterior capsule tears. Intraocular lens insertion, especially that of the foldable plate-haptic silicone IOLs with the Passport injection system, is simple and easily reproducible. There have been no reports of significant complications other than failure of the lens to unfold. We report a case of posterior capsule rupture at the time of IOL injection after uneventful phacoemulsification in a patient with inadequate pupil dilation.
A 75-year-old man had a 6.0 mm pupil before the start of phacoemulsification. A 5.0 mm capsulorhexis was successfully completed. The phacoemulsification was done using the divide-and-conquer technique. The pupil constricted further during the procedure and by the end of the cortical cleanup, it was 3.0 to 4.0 mm. The bag was inflated with hydroxypropyl methylcellulose 2% (HPMC).
After the plate-haptic IOL (C10 UB, Chiron) was loaded into the injector, it was inserted through the temporal corneal incision. As the edge of the capsulorhexis was not visible because of pupillary miosis, the injector was held slightly more vertically than normal to ensure in-the-bag IOL placement. As the insertion was being completed, the IOL unfolded and was quickly lost into the vitreous cavity. An anterior vitrectomy was performed and because the pupil was very small and the edge of the capsulorhexis not visible, primary IOL implantation was abandoned.
The eye was quiet the next morning, and visual acuity was 6/9 with aphakic correction. The patient received a secondary posterior chamber IOL in the sulcus. Uncorrected visual acuity was 6/6 3 months postoperatively with the dislocated lens remaining in the vitreous cavity.
The Passport system of plate-haptic foldable silicone IOL implantation is easy, safe, and reproducible. In most cases, no further manipulation is required other than an occasional need to change the injector's orientation. There have been a few case reports of IOL and tube damage during implantation,2 and it is important to carefully position the IOL on the loading deck.
Another reported complication is the failure of the IOL to advance or unfold as the plunger is pushed.3 To prevent the lens from unfolding in the sulcus, it is important to ensure that the lens' leading edge is under the anterior capsule edge.
In our patient, the anterior capsule edge was not visible because of pupil constriction. Therefore, the capsular bag was inflated with HPMC, after which the injector was held a fraction more vertically to ensure in-the-bag opening of the IOL. As the injection commenced, the entire IOL unfolded under the iris and was difficult to observe. The exact cause of the capsular tear could not be ascertained, even after the entire procedure was reviewed on video. However, we are certain that the posterior capsule was intact before the injection, and the capsular bag appeared to be adequately inflated with HPMC. It is possible the tear was caused by trauma from the lens injector or the IOL tip as it unfolded in the bag.
We used HPMC as an ophthalmic viscosurgical device (OVD) to expand the capsular bag, which is our normal practice. It is possible that the HPMC, which has very low viscosity (∼6000 mPas), may not have fully inflated and stabilized the bag,4 allowing the edge of the incoming IOL to catch a fold of the posterior capsule, causing it to rupture. In retrospect, we believe that the injector was advanced too far and held too vertically below the presumptive position of the anterior capsule edge. This, along with possible incomplete expansion of the capsular bag, may have resulted in too little space for the IOL to unfold. Continued injection caused it to catch and tear the posterior capsule and then sink into the vitreous. We have implanted more than 1000 plate-haptic silicone IOLs using this technique without a similar complication.
The posterior capsule rupture may have been avoided by using a viscocohesive OVD such as sodium hyaluronate 1.0% (Healon®) or sodium hyaluronate 1.4% (Healon GV®) or perhaps a viscodaptive OVD such as sodium hyaluronate 2.3% (Healon5®) to expand and stabilize the capsular bag. These agents, with much higher zero shear viscosities, may help dilate the pupil, allowing greater visibility of the capsulorhexis.5 Also, keeping the injector slightly obliquely, not advancing it too far under the capsular rim, and withdrawing the injector as the IOL emerged from its tip may have permitted more space for smoother unfolding of the IOL, preventing the posterior capsule rupture.
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2. Olson RJ. Passport system cutting of a Chiron C10 UB silicone lens (letter). J Cataract Refract Surg 1996; 22:282
3. Dada T, Sharma N, Dada VK. Complications with the Passport placement system (letter). J Cataract Refract Surg 1998; 24:1170-1171
4. Arshinoff S. The safety and performance of ophthalmic viscoelastics in cataract surgery and its complications. In: Arshinoff S, ed. Proceedings of the National Ophthalmic Speakers Program, 1993; 21-28
5. Arshinoff S. Dispersive and cohesive viscoelastic materials in phacoemulsification revisited 1998. Ophthalmic Pract 1998; 16:24-32