Phaco over trab or shunt for PACG

Cataract extraction may be better first surgical option than trab or tube

Howard Larkin

Posted: Tuesday, October 1, 2019

Reay H Brown MD

The proven success of phacoemulsification in treating primary angle closure glaucoma (PACG) makes cataract surgery a better first-line surgical treatment choice than trabeculectomy or tube shunts with their related complication risks, Reay H Brown MD told the Glaucoma Subspecialty Day at the ASCRS ASOA Annual Meeting, in San Diego, USA.

“This is very evidence based. Phaco is an effective glaucoma treatment in all stages of angle closure – early or late, IOP normal or high, cataract or clear lens, even with angles closed for years,” said Dr Brown, of Atlanta, USA.

Dr Brown’s experience with phaco for angle closure dates back more than a decade, when he treated a 47-year-old woman with multiple iridotomies and angles closed for six years on maximum medications.

With her intraocular pressure (IOP) spiking to 31mmHg and nerve cupping in the right eye, a glaucoma specialist recommended trabeculectomy. Dr Brown tried clear-lens cataract surgery and goniosynechialysis instead.

Today, the patient’s IOP runs in the teens with no meds and 20/20 vision.

“It’s like she doesn’t even have glaucoma. She’s much better off without a tube or trab,” he said.

The case was among those he submitted for an early case series demonstrating the potential of cataract surgery as a PACG treatment (Brown et al. JCRS 2014; 40:840-841). The EAGLE study confirmed the concept, recommending clear-lens extraction as a first-line option for treating PACG (Azuaro-Blanco et al. Lancet 2016; 388:1389-1387).

Poor IOP control on multiple medications is a good indication that surgery may be needed, particularly if pilocarpine is one of the meds, Dr Brown said.

“Chronic pilocarpine is … nature’s way of telling you that you need to do cataract surgery,” he noted.

Long-term pilocarpine can result in small, fibrotic pupils, Dr Brown noted. However, such cases can be successfully managed with careful pupil expansion and devices including iris hooks and the Malyugin ring, he said.

Ultra-shallow anterior chambers may be the most difficult challenge in angle-closure phaco, Dr Brown said. In cases where the chamber is too shallow or the pupil touches the cornea, about five seconds of dry pars plana vitrectomy can deepen the chamber enough for cataract extraction.

“It may take all of our surgical skills, but most of the time the cataract surgery is routine. The main challenge is not how [to surgically treat PACG] but why and when,” Dr Brown concluded.

Reay H Brown: