Two in One

Cataract surgery is the most commonly performed operating room procedure in elderly patients in the US, and it’s estimated that over 3.5 million cataract operations are performed each year in the country (1). Many pars plana vitrectomies (PPVs) are also performed in the US each year – and by tabulating Medicare utilization data, we identified that close to 23,000 vitrectomies were performed in 2014 (2). Our point? The potential for an increase in concomitant retinal and lens-related disorders is only going to escalate in this aging population.

The overwhelming majority of phakic patients who undergo vitrectomy develop visually significant cataracts (with the risk increasing with age) whether or not gas tamponades are used (3)(4) – yet this has not translated into the adoption of phacovitrectomy by vitreoretinal surgeons in the US. By comparison, glaucoma surgeons commonly perform cataract surgery combined with trabeculectomy or tube shunt surgery (5), and we suspect that the familiarity with cataract surgery by the glaucoma specialist has fueled this trend.

In the US, cataract and retinal surgery are performed as separate events. Though there are advantages to that approach (as we discuss below), combining these procedures may ultimately benefit the patient and the health care system by decreasing both the operative and postoperative burden. Developed nations outside of the US have already adopted a combined approach, as vitreoretinal surgeons outside of the US perform cataract surgery. We believe that changing this practice in the US needs to begin with changing the model in US vitreoretinal training programs. Addressing fellowship training is beyond the scope of this article, instead we hope to highlight the advantages of phacovitrectomy and discuss how the two-surgeon model may work to streamline care for patients with cataracts who undergo vitreoretinal surgery.

Financially, there are potential advantages to phacovitrectomy. An analysis of phacovitrectomy vs. sequential surgery resulted in an approximate 20 percent cost savings to Medicare in favor of phacovitrectomy (6). By streamlining this surgical process, patients may also directly benefit from a reduced number of surgical and post-operative visits.

Aside from fiscal implications, there are surgical advantages to phacovitrectomy too. Phacoemulsification in a post-vitrectomy eye has a higher complication rate that could be caused by a variety of factors, including weakened zonules, unstable posterior capsules, and potential defects in the posterior capsule, which may sometimes lead to an additional surgery (7).

Another reason for considering phacovitrectomy is the higher likelihood of developing visually significant cataracts following PPV, which may occur as a result of increased oxygen tension in the lens (8). However, the development of a visually significant cataract after PPV is not universal. Performing the vitrectomy alone may reduce the number of patients that ultimately undergo cataract extraction.

Phacovitrectomy does have disadvantages for the vitreoretinal surgery in certain cases. Prolonged cataract extraction with corneal edema may make retinal viewing paradoxically more difficult in combined cases – and this becomes especially important in patients who have significant endothelial cell dysfunction.

For the cataract surgeon, surgery may also be more difficult in some situations. Dense vitreous hemorrhage may result in a poor red reflex. Hypotony due to a retinal detachment may lead to chamber instability. Intraocular lens (IOL) calculations may also be less predictable in patients who may potentially need silicone oil or scleral buckle placement. Phacovitrectomy may also result in higher postoperative refractive unpredictability in cases that require repair of extensive rhegmatogenous retinal detachments (9). Waiting until the retinal outcomes are determined may also influence consideration of accommodative or multifocal IOLs.

However, given the potential advantages of phacovitrectomy, in our academic US practice, we prefer a two-surgeon approach. When planning combined phacovitrectomy, patient counseling is paramount. Best corrected visual acuity will often depend on the underlying retinal pathology. IOL selection should also be discussed carefully; we do not recommend multifocal IOLs in patients with retinal pathology. However, with small gauge vitrectomy systems that seem to minimally affect corneal astigmatism, toric IOLs can be beneficial when the patient has good potential for visual recovery.

The cataract surgery is performed through a temporal incision while the vitrectomy is performed with the vitreoretinal surgeon operating superiorly. The scope can easily be rotated with both surgeons in position. We start with the placement of all three pars plana trocar cannulas – this is easier than when placing them through a soft globe after cataract extraction and prevents wound gape that may prolapse or decenter the IOL. The infusion is not initiated; otherwise undue posterior pressure can result. The capsulorhexis is made to approximately 5 mm in size. We do not recommend making the rhexis significantly smaller – it merely inhibits efficient cataract extraction and we have found that it does not reduce the chance for IOL prolapse out of the capsular bag. We prefer foldable acrylic aspheric IOLs given the superiority of the optics compared to three-piece acrylic spheric lenses. We have seen both styles of lens prolapse out of the bag when the posterior segment is over-pressurized. By limiting wound hydration, the cornea remains clear for the vitrectomy. We often suture the main corneal wound to ensure chamber stability during the vitrectomy and have recently found that corneal sealants work well for this purpose.

Some may argue that eyes with multiple ocular pathologies cannot tolerate the increased inflammation associated with combining surgery – but there is little evidence to support this (10). We suspect that in highly diseased eyes, minimizing the number of surgeries may decrease the chance of endothelial compromise. Phacovitrectomy may limit the exposure to pathogens that can cause endophthalmitis. We also suggest that combining surgeries decreases the systemic risk to the patient. Reducing the number of times insulin regimens are adjusted, meals are withheld, and sedation is performed may be advantageous in patients with poorly controlled diabetes. These patients also exhibit an increased incidence of cataract and retinal disease and are the very patients whom we feel benefit the greatest with this approach. There are several studies that support our line of reasoning (11). When we consider all the advantages for the patient and surgeon, we believe phacovitrectomy is a sensible option.