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Contemplating pars plana procedures for cataract surgeons

Imagine you are performing a routine cataract surgery when there is a turn of events. In that brief moment, the routine case becomes a heart-pounding thriller. The posterior capsule is torn and the lens has dislocated into the anterior vitreous cavity. Unfortunately, this situation occurs not too infrequently. Should the cataract surgeon proceed if he/she feels comfortable operating via the pars plana? Are there boundaries, and if so, who defines the boundaries?

Bonnie An Henderson, M.D., cataract editor

Dr. Charles enters the vitreous in very limited circumstances, such as during vitreous loss after posterior capsule rupture (pictured here) Source: David Allen, F.R.C.Ophth.

Weighing the current wisdom

It is something that remains an area of contention—should anterior segment surgeons be entering the pars plana for procedures such as planned PPV or posterior assisted levitation (PAL)? EyeWorld spoke with two leading ophthalmologists to get their perspectives on this.

Point

Richard Packard, M.D., senior consultant, Prince Charles Eye Unit, Windsor, England, sees the issue of entering the pars plana as one that reflects anterior surgeons' comfort level. "I think that it depends on whether they feel comfortable there and whether they're prepared to do a complete peripheral retinal check afterward to make sure that there aren't any breaks," he said. "If they don't [feel comfortable] then they shouldn't." He pointed out that many of those who express interest in doing this have a rigorous background in it. "The people who are keen on doing this, a lot of them have been trained as ER surgeons anyway," he said.
When it comes to a rescue technique like PAL, Dr. Packard acknowledged that ER surgeons caution anterior segment practitioners against this. He, however, has been doing this on occasion for 20 years. Deciding whether or not to undertake the PAL maneuver as an anterior segment surgeon depends on the individual case, he believes. "If the nucleus is sort of hovering on the front of the anterior hyaloid, then doing some sort of PAL maneuver is probably perfectly acceptable for an anterior segment surgeon," Dr. Packard said. "But if it has gone any further than that, the surgeon shouldn't start fishing around in the vitreous cavity."
Dr. Packard's experience here has been pretty positive. "I've done the PAL maneuver probably a half dozen times in the last 20 years, and I have not in any of those cases needed to call in the services of a vitreoretinal surgeon," he said. He recommended that any anterior practitioner who is thinking of performing procedures in the posterior segment such as posterior vitrectomy or PAL be prepared to thoroughly check for peripheral breaks afterward. "If the surgeon sees a break, he needs to call a colleague, or if he feels comfortable he can deal with it as required," Dr. Packard said.
From a medical legal perspective, anterior segment surgeons need to abide by the facility's guidelines. "If it says in the guidelines that it's acceptable for anterior segment surgeons to go through the pars plana and they feel that they've had adequate training to be able to do it, then I wouldn't think that there are any medical legal consequences," Dr. Packard said. If something untoward does happen, the anterior surgeon has the backing of the guidelines, just as a retinal surgeon would.
Overall, Dr. Packard sees pros and cons to all of this. "The most important thing is that when surgeons undertake any procedure, they have to be able to deal with the consequences of their actions," he said. "That's what it comes down to."

Counterpoint

Steve Charles, M.D., clinical professor of ophthalmology, Hamilton Eye Institute, University of Tennessee, Memphis, and founder, Charles Retina Institute, Memphis, has another view. He sees entering the vitreous cavity as appropriate only in very limited circumstances. "This should be done only for vitreous loss after posterior capsule rupture during cataract surgery, traumatic cataract cases with a damaged capsule, or secondary IOL implantation with vitreous in the anterior chamber—never for floaters or asteroid hyalosis," Dr. Charles said.
Trouble can brew quickly, he pointed out. "The problem with simple cases is that they're no longer simple if you make a complication," Dr. Charles said. "Simple cases can become radically complicated and patients can have a bad outcome." There are a myriad of pitfalls that the anterior surgeon can face. "There can be retinal detachment caused by intraoperative vitreoretinal traction from cellulose sponges or sweeping the wound using anything less than maximum cutting rates, using excessive vacuum or flow rates, or withdrawing the cutter while vacuum is applied," Dr. Charles said. Before a practitioner who was attempting a "simple vitrectomy" because the IOL was dislocated in the vitreous cavity knows it, he may be facing a folded retina, Dr. Charles said.
In his view, the issue comes down to being able to offer the patient the best result. Dr. Charles feels strongly that as a retinal surgeon he shouldn't be doing elective cataract surgery and only reserves procedures such as phaco-vit for complicated retinal cases where the expectation of the patient isn't emmetropia with no residual refractive error. He pointed out that as a retinal surgeon he can't hope to achieve the same refractive outcomes as an anterior segment specialist. "If we're doing elective macular surgery where the outcome is expected to be 20/20, 20/25, or 20/30, we need to have the cataract surgeon do the cataract surgery at a separate setting under optimal conditions," he said. Conversely he believes that the same should apply to the cataract surgeon. He emphasized the difficulty and complexity of vitreoretinal surgery and the need for proper training. "So-called 'simple cases' can become intraoperative disasters with large retinal tears if inappropriate and all-too-common mistakes are made," he said.
Dr. Charles thinks that anterior segment surgeons who perform procedures such as pars plana vitrectomy may actually find themselves in precarious medical legal territory. "The basis for malpractice litigation is the standard of care," he said. Performing pars plana vitrectomy for anything other than very select cases such as the ones he mentioned does not conform to the current standard of care, he believes.
He pointed out that the training period for retinal fellows is 2 years, and during that time he stays in the room while they are performing surgery to inspect their work and take over if needed. Overall, Dr. Charles thinks that the future of ophthalmology is in gaining expertise in specific areas. "Advances in medical outcomes have occurred not just because of better technology but because of increasing specialization," he said. As someone who has done over 29,000 vitreoretinal cases, he stressed that he follows this model. "I strongly practice what I preach and that is specialization," Dr. Charles said.

Editors' note: Dr. Charles has financial interests with Alcon (Fort Worth, Texas). Dr. Packard has no financial interests related to this article.

Contact information

Charles: 901-767-4499, scharles@att.net
Packard: 44-20-75801074, eyequack@vossnet.co.uk