Article

A Closer Look at Combined Cataract and Vitreoretinal Surgery

Is together better?

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Cataract formation and progression are inevitable sequelae of pars plana vitrectomy (PPV), and the vast majority of patients who undergo PPV will require subsequent cataract surgery.1-5 Postvitrectomy cataract development may also blunt visual gains achieved by the initial retinal surgery. All of these factors can result in an unhappy patient.

Therefore, some surgeons have elected to integrate cataract and vitreoretinal surgery into one procedure, henceforth referred to as phacovitrectomy or combined surgery. Notably, combined surgery will be discussed here from 1-surgeon (ie, retina surgeon performing the entire surgery) and 2-surgeon (ie, cataract surgeon works with a retina surgeon during the same surgery) perspectives. My own practice experience includes both scenarios. This article will also discuss some of the advantages and disadvantages of combined surgery and conclude with some practical surgical pearls.

BENEFITS OF COMBINED SURGERY

The most obvious potential advantage of combined surgery is sparing the patient from a future procedure with its own separate recovery process, costs, and anesthesia and surgical risks. The cataract surgeon may actually prefer combined vs sequential surgery (PPV followed by a separate cataract surgery) given the higher complication rate of phacoemulsification in vitrectomized eyes.6

Combined surgery can improve visualization for more detailed retinal work, such as internal limiting membrane or epiretinal membrane peeling, allow for a more thorough peripheral shave of the vitreous base, and facilitate postoperative surveillance. If the cataract is already quite advanced, the patient is more likely to experience a greater magnitude of postoperative visual improvement, leading to greater patient satisfaction.

Combined surgery also allows the patient to have a unidirectional visual improvement trajectory rather than experiencing initial visual improvement followed by decline due to cataract progression. Further, while the best interest of the patient should always be prioritized, from a socioeconomic standpoint, combined surgery may be more cost-effective than 2 separate surgeries.7

The published outcomes of combined surgery are quite good.8-10 In patients with cataract and proliferative diabetic retinopathy, combined and sequential surgeries appear to be equivalent in terms of safety and efficacy.11

Lahey et al described the results of phacovitrectomy for 89 patients with full-thickness macular holes and found that 89% of patients had their holes closed with combined, surgery with 65% having resultant visual acuity ≥20/40.12 This high rate of hole closure may be related to a more complete vitrectomy allowing for a better gas fill.13

Another study compared the visual outcomes of phakic patients with macular holes who underwent phacovitrectomy vs sequential surgery. The phacovitrectomy group sustained significant visual improvement during the first 6 months postoperatively, while the sequential surgery group had no improvement in visual acuity until they had their cataracts extracted, suggesting that combined surgery leads to a quicker visual rehabilitation.14

Combined surgery does not seem to be associated with a significantly greater risk of adverse events than sequential surgery. A retrospective study of 565 eyes found that the combination of phacoemulsification with 25-gauge PPV for vitreomacular diseases (epiretinal membrane, vitreomacular traction, or macular hole) did not result in an increase in postoperative complications, compared with 25-gauge PPV alone performed in pseudophakic eyes.15

Hamoudi et al studied a group of phakic eyes with epiretinal membranes to evaluate the impact of sequential surgery (PPV followed by cataract surgery) and phacovitrectomy on corneal endothelium cell density. They found that both combined and sequential surgery led to a small decrease in endothelium cell density without a statistically significant difference between the two approaches.16

DRAWBACKS OF COMBINED SURGERY

Of course, there are also disadvantages of combined surgery that must be considered. While the long-term visual rehabilitation may be faster for those undergoing combined surgery, not surprisingly, these patients tend to have more postoperative inflammation and a longer acute recovery period than those undergoing isolated PPV or cataract surgery. This inflammation is thought to be associated with higher rates of posterior capsular opacity, posterior synechiae, and cystoid macular edema among patients treated with phacovitrectomy;12,17-18 some surgeons address this concern with a prolonged treatment course of steroids and careful monitoring.

Combined surgery itself can pose additional challenges that either surgeon would not face with separate surgeries. For patients with vitreous hemorrhage, the red reflex may be diminished, rendering the phacoemulsification portion of the surgery more difficult. If the cataract happens to be very dense, the cornea can become edematous during phacoemulsification, compromising the retina surgeon’s view.

Refractive outcomes may be less predictable for phacovitrectomy patients. While PPV itself is thought to possibly exert a myopic shift, intraocular lens (IOL) calculations may be less reliable in patients with certain pathologies, such as retinal detachment or macular edema.

Some surgeons recommend using partial coherence interferometry (eg, IOLMaster; Carl Zeiss Meditec) to measure axial length as opposed to ultrasound biometry, which can lead to a myopic refractive error. Additionally, any tamponade that is placed during vitrectomy subjects the IOL to possible displacement, opacification, or pupillary capture.

There are also nonmedical issues associated with combined surgery. From a logistical standpoint, coordinating a combined surgery between 2 surgeons can be very burdensome, especially if the retina surgeon is not in a practice that includes a cataract surgeon. Most third-party payors reimburse 100% for the retina procedure and 50% for the phacoemulsification. Hence, unless the retina surgeon performs the entire procedure, the cataract surgeon may be financially disincentivized to perform combined surgery.

Some retina surgeons perform both the phacoemulsification and the PPV themselves, but they likely represent a minority. When retina surgeons perform cataract surgery themselves, it has the potential to negatively impact referral relationships with anterior-segment specialists, although this impact may not occur depending on the practice landscape.

SURGICAL PEARLS FOR COMBINED CATARACT SURGERY AND VITRECTOMY

If you decide to proceed with a combined surgical approach, there are many important considerations that should be taken at various steps of the perioperative process.

Preoperatively

Preoperative counseling is critical, and expectations must be aligned so that patients are prepared for a slower recovery (eg, their cataract extraction may not lead to 20/20 vision the next day like their neighbor’s did). If 2 surgeons are involved, ensure that both have individually obtained consent from the patient so that the patient understands that both surgical components carry risks.

Be mindful of IOL selection. Axial length measurements should consider details such as whether the patient has oil in the eye, for which adjustments would need to be made. If there is a possibility that a tamponade will be placed, hydrophilic and silicone IOLs may not be a suitable choice due to their greater susceptibility to opacification. Intraocular lenses with larger optics (>6 mm) enhance the peripheral view during vitrectomy and can also prevent anterior IOL dislocation if a tamponade is used. Multifocal IOLs may not be advisable in patients with concurrent macular pathology, such as an epiretinal membrane.

Engage in careful surgical planning prior to the actual surgery. If you are working with another surgeon, discuss surgeon order (eg, in a patient with retained silicone oil, it may be preferred to first remove the oil, then extract the cataract, and then perform any other retina procedures) and incision placement. My cataract colleagues sit temporally, so I typically place the infusion line inferonasally if I start the case so that it is out of their way. If they start the case, I avoid placing trocars in the same meridian of the corneal wound to prevent wound gape.

Intraoperatively

Use a minimal retrobulbar block to avoid excessive posterior pressure, which can complicate the cataract surgery. I typically inject 3 mL of block and place the remainder on the field, supplementing as needed after cataract extraction. Do not hesitate to stain the anterior capsule with trypan blue. The normal red reflex in these combined cases may be significantly attenuated due to vitreous hemorrhage or other retina-related pathology (Figure 1).

Figure 1. A patient with cataract and nonclearing vitreous hemorrhage. Note the lack of red reflex due to the hemorrhage; staining with trypan blue dye aids in visualization of the anterior capsule.

Keep the capsulorrhexis diameter on the smaller side (Figure 2). Pressure from the infusion line or gas tamponade can anteriorly displace the IOL, and a smaller rrhexis will help to counteract posterior forces.

Figure 2. A patient with cataract and epiretinal membrane. Use of a corneal marker can guide capsulorrhexis formation. A smaller capsulorrhexis is generally preferred in combined surgery to prevent anterior prolapse of the intraocular lens.

Avoid hydrating corneal wounds, minimize the phacoemulsification energy utilized, and work away from the endothelium if possible (Figure 3). If the lens is dense, a dispersive viscoelastic may be used to protect the endothelium. These measures will help to preserve corneal clarity for any later detailed work, such as membrane peeling.

Figure 3. A patient with cataract and epiretinal membrane. Techniques such as nuclear chopping lessen the amount of phacoemulsification energy to which the endothelium is subjected. This decrease helps to optimize the view for the retina portion of the surgery.

Minimize iris manipulation to maintain dilation for the vitrectomy portion. If the pupil does constrict, iris expansion devices can be utilized.

I prefer to place the IOL immediately following the cataract extraction, rather than wait until after the vitrectomy. Some retina surgeons prefer to leave the viscoelastic in the anterior chamber (AC) until the end of the case to prevent AC collapse. In these cases it is important to aspirate the viscoelastic prior to closing to avoid postoperative intraocular pressure (IOP) elevation.

Some surgeons use the cutter to create a small posterior capsulotomy at the end of the case to prevent future opacification. I do not typically do so as I prefer to allow the capsule to first fibrose and stabilize the IOL; a YAG capsulotomy can be easily performed at a later date.

Suture all corneal and scleral wounds in combined cases. Even with the best corneal wounds, the transient spike in IOP during trocar insertion can cause prolapse of ocular contents. One preventative approach is to place the (clamped) infusion line at the start of the procedure (Figure 4). Suturing sclerotomies in combined cases can minimize the risk of postoperative hypotony. Check the positioning of the IOL following PPV to ensure that it is still centered and in its intended location.

Figure 4. A patient with dense cataract and rhegmatogenous retinal detachment. The infusion line valved cannula (circled) has been placed prior to starting the cataract extraction. This placement prevents globe collapse and iris prolapse, which can occur with trocar placement in the presence of corneal wounds.

At the conclusion of the case, consider injecting a steroid into the subconjunctival or sub-Tenon space; doing so may temper the postoperative inflammation that results from these combined cases due to increased manipulation and longer duration.

Postoperative

Many surgeons opt to forego dilating the patient in the early postoperative period to prevent IOL dislocation. Also, fibrin is often seen in the AC on the first postoperative day due to inflammation; it can resemble viscoelastic or vitreous, and it typically resolves within the first week. Consider increasing the topical steroid regimen if you see a significant fibrinous reaction.

If the patient is positioned face down, you may observe small amounts of hemorrhage along the posterior surface of the IOL or in the AC; this hemorrhage typically resolves within the first week. The IOL optic may appear to be bowed anteriorly in the initial postoperative period if a gas tamponade was placed. As long as the haptics remain in the bag (or sulcus if a sulcus IOL was placed), the IOL will retreat into its intended position as the gas dissipates.

CONCLUSION

Combined surgery by vitreoretinal surgeons is quite common outside of the United States, but it has been slower to gain traction domestically. Although cataract extraction at the time of vitrectomy is not always indicated, it is a good option to offer patients in certain situations, especially if the cataract is already quite advanced. Recent advancements in technology have made combined surgery safer than ever, and there are several vitrectomy machines that offer integrated phacoemulsification capabilities.

While some unique challenges exist in terms of the planning and execution of simultaneous cataract-vitreoretinal surgery, these challenges can generally be overcome with appropriate modifications. With the potential for improved postoperative vision and the elimination of a subsequent surgery, combined surgery is worth considering for select patients affected by retinal pathology. RP

REFERENCES

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