Pointers to Prevent Posterior Capsular Rupture

Cataract surgeons who claim they're not worried about piercing the posterior capsule with a sharp instrument or oscillating phaco tip? "They're either lying or retired," says Uday Devgan, MD, a cataract surgeon in Los Angeles, Calif.

While posterior capsular ruptures are rare — it's estimated they occur in 6% of novice surgeons' cases and in less than 1% of experienced physicians' procedures — they increase the risks of endophthalmitis and cystoid macular edema, adverse events that adversely affect patients' post-op vision. But a rupture impacts more than quality outcomes. Your case costs and profit margins suffer collateral damage. Consider:

• Surgeons must open 2 or 3 more tubes of viscoelastic to keep the tear from expanding, and prevent or limit vitreous loss.
• They must use intracameral preservative-free triamcinolone during clean-up of the tear to increase visualization of the vitreous that prolapses into the anterior chamber.
• They must open an anterior vitrectomy pack, use acetylcholine chloride intraocular solution to constrict the pupil, and administer additional steroids or antibiotics.
• And your surgeons might have to insert a three-piece IOL, which is less likely to expand the tear, instead of a two-piece IOL.

All of those steps and additional supplies more than double the duration of surgery and inflate your case costs, says Dr. Devgan, stressing that you can't afford to waste minutes and dollars in a volume-driven specialty with razor-thin profit margins.

Fortunately, advanced phaco fluidics, femtosecond-lasers and mydriasis-maintaining drugs can help prevent tears from occurring.

Dr. Whitman is more aware of the risk of a posterior capsular tear occurring when he operates on patients with floppy iris syndrome, previous eye trauma or phacodonesis, which is seen in patients with pseudoexfoliation and weakens the zonular fibers that stabilize the posterior capsule.

He says using a femtosecond laser to fragment dense cataracts lowers the risk of capsular rupture during cataract extraction by limiting the stretching of zonular fibers attached to the capsular bag and lessening the amount of force applied to the bag. It also means you can remove lens fragments with minimal phaco energy (tears are more likely to occur during increased phaco times and when more ultrasound energy is needed to fragment dense and brunescent cataracts).

Part of the appeal of femtosecond laser cataract surgery for Dr. Whitman can't be quantified or reported on in the pages of peer-reviewed journals. "My heart rate lowers, I have more confidence," he says. "I believe I'm about to perform a safer, more efficient and predictable procedure with fewer complications, especially during high-risk procedures involving dense cataracts."

Dr. Whitman points out that surgeons can also reach for the miLoop, a single-use, pen-like device with a nitinol loop that's used to quarter cataracts, making extraction easier. "We now have tools that can help us reduce ultrasound time and energy, and the movement of instruments within the capsular bag," says Dr. Whitman.

Maintaining adequate pupil size during cataract surgery is obviously important. "You run into problems if you can't see what you're doing," says Dr. Whitman. He'll operate on softer cataracts with pupils at 4.5 mm to 5 mm, but prefers to begin with the pupil at 6 mm during cases involving dense cataracts.

Intraoperative miosis naturally occurs during procedures, and even a millimeter of constriction can significantly impact visualization of the anterior chamber. Omidria, an FDA-approved irrigating solution containing phenylephrine and ketorolac administered through balanced saline solution, is an effective option for maintaining pupil dilation, says Dr. Whitman, adding that pupillary rings and expanders "are guaranteed to work" in patients with small pupillary openings.

Many surgeons use epinephrine-Shugarcaine solutions as an intracameral anesthesia and to maintain pupil dilation, says Dr. Whitman, who prefers to use phenylcaine, which contains the dilating agent phenylephrine and the local anesthetic lidocaine. The combination keeps pupils open wider and longer than epi-Shugarcaine and maintains dilation for an entire case, he says, especially when using today's quicker and more efficient phaco systems.

Dr. Whitman has performed close to 60,000 cataract procedures, but still feels a twinge of fear every time he peers into the oculars and considers the long list of potential complications that could occur during the case he's about to begin.

Dr. Whitman thinks back to the cataract surgeries he performed on twins, each of whom had posterior polar cataract in both eyes. The procedures were routine for 3 of the eyes, but the posterior capsule ruptured during the fourth and final case. It was a good reminder of how unpredictable one of surgery's most predictable procedures can be.

"You never know when something will go wrong," says Dr. Whitman. "That's what keeps me on my toes."

He always takes a deep, calming breath before making the first incision, knowing his skill and experience will combine with advanced technologies to lower the risk of the complication all cataract surgeons dread — regardless of whether they admit it. OSM