Oval opening boosts phaco safety in cases of posterior polar cataract with ruptured capsule

A low fluid rate and a large opening in the anterior capsule minimize turbulence in the capsular bag, study author says.

Vikas Mittal

Oval capsulorrhexis in lieu of a circular capsule opening enabled safe and easy phacoemulsification in cases of posterior polar cataract with pre-existing posterior capsule rupture, a study found.

The method reduced turbulence in the capsular bag, facilitated removal of nuclear fragments and reduced the risk of nucleus drop, the study authors said.

The oval capsulorrhexis technique is a suitable alternative to the traditional large and small circular configuration but has advantages of both, Vikas Mittal, MS, the corresponding author, told Ocular Surgery News in an email interview.

“We want something in between small and big circular curvilinear capsulorrhexis, which has benefits of both and bad points of none,” Dr. Mittal said. “Oval capsulorrhexis has advantages of both smaller and larger capsulorrhexis.”

In a study of 10 eyes of eight patients with posterior polar cataract and pre-existing posterior capsule defect, mean logMAR corrected distance visual acuity improved from 0.221 preoperatively to 0.75 postoperatively at 6 months. No cases of nucleus drop or cystoid macular edema were reported, and all IOLs were stable.

Study results were published in the Journal of Cataract and Refractive Surgery.

Low fluid, vacuum rates

The technique was performed through a 2.8-mm clear corneal tunnel between the 10 o’clock and 12 o’clock positions. A bent 26-gauge needle was used to create an oval capsulorrhexis of approximately 8 mm by 4.5 mm. A bent 24-gauge cannula was used to perform gentle and complete hydrodelineation.

Slow phacoemulsification was performed with a low fluid flow rate and low vacuum (60 mm Hg to 80 mm Hg).

The large opening in the anterior capsule allowed continuous efflux of fluid and minimized turbulence in the capsular bag. The smaller axis of the oval capsulorrhexis facilitated capture of the IOL haptic in cases with sulcus-fixated posterior chamber IOLs.

The stop-and-chop technique was used in grade 2 to grade 4 nuclear scleroses. Phacoaspiration was used in grade 1 nuclear sclerosis.

“Initial trenching of the nucleus is easily done from one end to another in the meridian of the larger axis of the capsulorrhexis,” Dr. Mittal said. “Since the overall diameter of the capsular opening is more, it is very easy to take the individual nuclear fragment out of the bag without pull, push or rotational movement.”

An IOL was located in the bag or sulcus, depending on length of the posterior capsular rupture.

“When the capsulorrhexis is oval, the haptic of the foldable lens lands on the posterior capsule itself and the lens goes inside without rotation,” Dr. Mittal said. “Further, in cases where it needs to be implanted in the ciliary sulcus, the optics can be captured with the smaller axis of the capsulorrhexis, which ensures stability of the IOL.”

In cases requiring vitrectomy after IOL placement, the vitrectomy probe was safely directed behind the IOL through the larger axis of the capsulorrhexis, Dr. Mittal said. – by Matt Hasson

Reference:

• Singh K, Mittal V, Kaur H. Oval capsulorrhexis for phacoemulsification in posterior polar cataract with preexisting posterior capsule rupture. J Cataract Refract Surg. 2011;37(7):1183-1188.

• Vikas Mittal, MS, can be reached at Cornea and Anterior Segment Services, Sanjivni Eye Care, Model Town, Ambala, Haryana 134 002, India; email: vikas_mittal@hotmail.com.
• Disclosure: Dr. Mittal has no relevant financial disclosures.