Newer techniques help manage small pupils during phaco

May 15, 2005

Dorado Beach, Puerto Rico—Newer techniques for managing the small pupil are effective, thus enabling safer phacoemulsification. Stephen Obstbaum, MD, reviewed the techniques that are available and demonstrated their use at the Current Concepts in Ophthalmology meeting.

Dorado Beach, Puerto Rico-Newer techniques for managing the small pupil are effective, thus enabling safer phacoemulsification. Stephen Obstbaum, MD, reviewed the techniques that are available and demonstrated their use at the Current Concepts in Ophthalmology meeting.

"Numerous techniques have been used over the years in an attempt to dilate the pupil," he said. "Over the past few years, the adjunctive use of an ophthalmic viscosurgical device with particular characteristics has become increasingly helpful." Dr. Obstbaum spoke during the conference, sponsored by Johns Hopkins University School of Medicine, Baltimore, and Ophthalmology Times.

Dr. Obstbaum also strongly suggested the use of topical, nonsteroidal anti-inflammatory drugs before surgery in these eyes. Intraoperatively, if posterior synechiae are present, they should be lysed; in addition, any pupillary membranes that are evident should be stripped. Surgeons can also use intracameral preservative-free epinephrine 1:10,000, explained Dr. Obstbaum, chairman, department of ophthalmology, Lenox Hill Hospital, and professor of ophthalmology, New York University School of Medicine, both in New York.

Techniques that were considered standard in the past include sector iridectomy, radial sphincterotomy, or multiple sphincterotomies, although the effect did not necessarily produce desirable cosmetic results.

Newer approaches Newer techniques include the use of a partial radial sphincterotomy with a preplaced suture, multiple incomplete mini-sphincterotomies, pupil-stretching techniques, and pupil maintainers. The use of small scissors for micro-sphincterotomies can result in a cosmetically acceptable pupil compared with an "ungainly looking pupil," as a consequence of previous methods for sphincterotomy Dr. Obstbaum described.

Pupil-stretching techniques have gained popularity in recent years. This procedure uses two iris retractors or iris hooks, or small two- or three-point dilators.

"These stretching techniques generally provide an adequately sized pupil for phacoemulsification that can be maintained with the introduction of an ophthalmic viscoelastic device such as Healon 5," he said.

The use of self-retaining iris retractors maintains pupil size during the procedure and the retractors are removed at the completion of the operation. When placing the individual iris retractors such as the DeJuan or Mackool types, Dr. Obstbaum pointed out that optimally the surgeon should do so peripherally and in the plane of the iris, if possible, to avoid a tenting effect that can occur if the entry into the anterior chamber is too vertical.

"When comparing all of the recent techniques, all methods are effective. The pupil dilator ring and iris retractors are a bit more time-consuming to use; however, they provide the most stable pupil size compared with the other techniques. The pupil dilator ring is the least traumatic to the iris long term," he said. These results were published in Ophthalmology last September by Akman et al.

Dr. Obstbaum emphasized the pupil-dilating effect of viscoelastic agents, especially with small pupils.

"There are two properties of viscoelastics. Some viscoelastics, such as ProVisc (Alcon Laboratories), Healon (AMO), Healon GV (AMO), and Amvisc Plus (Bausch & Lomb) are cohesive; some are dispersive, such as Viscoat (Alcon)," he said.

The newest type of viscoelastic is the viscoadaptive Healon 5 (AMO). This agent acts as a cohesive agent at low settings, but fractures at higher settings and affords good protection, according to Dr. Obstbaum.