A posterior capsule rupture (PCR) is an uncommon complication that can occur during cataract surgery. The natural lens is enclosed within the lens capsule. During a standard procedure, the cloudy lens material is removed, leaving the posterior capsule intact to support the artificial intraocular lens (IOL). A PCR is an unintended tear in this membrane, which compromises the lens support structure. This event allows the vitreous, the gel-like substance filling the back of the eye, to move forward into the front chamber.
Causes of Capsule Rupture
A posterior capsule rupture can be caused by pre-existing patient conditions or factors arising during the surgical procedure. Certain patient characteristics create a more challenging surgical environment, significantly raising the risk of rupture. These risk factors include pseudoexfoliation syndrome, which weakens the supportive fibers of the lens, and the presence of dense or hard cataracts.
Eyes with a history of prior trauma, previous retinal surgery, or a posterior polar cataract also face a heightened risk. A posterior polar cataract is a specific type naturally fused to the posterior capsule. Anatomical challenges such as a small pupil, a shallow anterior chamber, or high myopia can limit the surgeon’s visibility and working space, increasing the likelihood of an accidental tear.
Intraoperative factors relate to the mechanics of the surgery, often occurring during cataract material removal or IOL insertion. Excessive pressure applied during hydrodissection, which uses fluid to separate the cataract from the capsule, can cause a tear. Problems with fluid dynamics, such as a sudden drop in pressure or an instrument inadvertently touching the membrane, can also lead to rupture. The risk of a PCR is reported to be between 1% and 3% in modern cataract surgery.
Immediate Surgical Response
When a posterior capsule rupture is recognized, the immediate priority is to stabilize the eye and prevent further complications. The first step involves injecting an ophthalmic viscosurgical device (OVD), a highly viscous substance, to plug the tear and tamponade the vitreous. This helps prevent the vitreous from prolapsing forward, stabilizes the pressure within the eye, and allows the surgeon to safely remove instruments.
The next step is managing the vitreous gel that may have prolapsed into the anterior chamber, a procedure called an anterior vitrectomy. This process uses a specialized cutting device to remove vitreous strands from the front of the eye, preventing them from causing traction on the retina. Dilute triamcinolone, a steroid, is often injected to stain the vitreous, making the otherwise transparent gel visible and ensuring its complete removal.
After the eye is stabilized and the vitreous is cleared, the surgeon decides on the placement of the artificial IOL. If the tear is small and the remaining capsule provides sufficient support, the IOL may be placed in the ciliary sulcus, just in front of the capsular bag. If there is extensive damage, the surgeon may opt for an anterior chamber IOL, which rests in the front part of the eye, or delay the IOL placement entirely. If large pieces of lens material fall into the back of the eye, the surgeon will not attempt retrieval; a retina specialist must be consulted for a separate procedure to remove the retained fragments later.
Potential Post-Operative Issues
Even when a posterior capsule rupture is managed effectively during surgery, it increases the risk of several complications in the post-operative period. One common issue is a temporary, but significant, rise in intraocular pressure (IOP), which can be an early sign of glaucoma. This pressure spike often requires additional medications to control it in the days and weeks following the procedure.
Another recognized complication is cystoid macular edema (CME), which is the swelling of the macula, the central part of the retina responsible for sharp vision. This swelling is caused by inflammation related to the surgical complexity and can blur the patient’s vision. While often treatable with eye drops, CME can slow down the visual recovery process.
The involvement of the vitreous also increases the risk of retinal detachment, where the light-sensitive tissue at the back of the eye pulls away from its normal position. Retinal detachment is a serious condition that requires prompt surgical repair to prevent permanent vision loss. The disruption of the capsule and the need for a more complex procedure slightly increase the risk of endophthalmitis, a severe infection inside the eye. This infection is rare but must be addressed immediately with antibiotic treatment.
Expected Recovery and Prognosis
A case complicated by a posterior capsule rupture involves a longer and more intensive recovery period compared to routine cataract surgery. The increased inflammation and trauma mean patients often use anti-inflammatory and antibiotic eye drops for an extended duration. Patients may require a higher number of follow-up visits with the eye surgeon to monitor closely for complications like elevated intraocular pressure or macular swelling.
Despite the increased complexity and risks, the long-term prognosis for eyes that experience a PCR is favorable when the complication is recognized and managed. Most patients achieve a good final visual outcome, often defined as a best-corrected visual acuity of 20/40 or better. If the initial IOL placement was delayed or if there were retained lens fragments, the patient may need a second, planned procedure to achieve the best possible vision.