Primary posterior capsulotomy using a 25-gauge vitreous cutter in vitrectomy combined with cataract surgery

Abstract

 

We describe a primary posterior capsulotomy technique using a 25-gauge vitreous cutter to prevent postoperative posterior capsule opacification (PCO) in patients with vitreoretinal diseases who must have a vitrectomy combined with cataract surgery. Following phacoemulsification, a 25-gauge vitrectomy, and intraocular lens implantation in the capsular bag, the posterior capsule is removed via a pars plana approach using a 25-gauge vitreous cutter; the removed capsule is round, well centered, and approximately 5.0 mm in diameter. This technique prevents postoperative PCO completely, improving vision and enabling detailed examination of the fundus after surgery.

Financial Disclosure: 

No author has a financial or proprietary interest in any material or method mentioned.

Posterior capsule opacification (PCO) is a major complication after vitrectomy combined with cataract surgery. In patients with vitreoretinal diseases, it is important to maintain clear visualization of the fundus after surgery, not only to improve postoperative vision, but also to enable detailed examination of the retina. Posterior capsule opacification can become more severe after vitrectomy combined with cataract surgery than after cataract surgery alone, resulting in impaired visual outcome and fundus visibility.^1,2 Because of this, patients with vitreoretinal diseases who have combined surgery often require a neodymium:YAG (Nd:YAG) laser capsulotomy, even though Nd:YAG lasers can cause complications such as elevated intraocular pressure, cracks in the intraocular lens (IOL), dislocation of the IOL, cystoid macular edema (CME), retinal detachment, and floaters.^3–10 To prevent PCO formation, we have developed a technique for performing a primary posterior capsulotomy using a 25-gauge vitreous cutter in a 25-gauge vitrectomy combined with cataract surgery.

SURGICAL TECHNIQUE

After topical and retrobulbar anesthesia are administered, a 3.0 mm superior clear corneal incision is made, followed by a continuous curvilinear capsulorhexis (CCC) of the anterior lens capsule, phacoemulsification with irrigation/aspiration (I/A), and a 25-gauge, 3-port pars plana vitrectomy. Fluid–air exchange is performed by injecting sulfur hexafluoride, when necessary. After an ophthalmic viscosurgical device (OVD) is inserted into the anterior chamber and capsular bag, a foldable acrylic IOL with a 6.0 mm round optic is implanted in the capsular bag. The posterior capsule is then removed from the center toward the periphery using a 25-gauge vitreous cutter and a pars plana approach, enabling the removal of a well-centered posterior capsule with a diameter of approximately 5.0 mm (Figure 1). The parameters of the vitreous cutter are a cutting rate of 2500 cuts/min and a vacuum of 600 mm Hg, the same as for the vitrectomy. Finally, the OVD is gently removed through the corneal incision with I/A.

Figure 1: Illustration of primary posterior capsulotomy using a 25-gauge vitreous cutter. A: The center of the posterior capsule is removed using a 25-gauge vitreous cutter and a pars plana approach. B: The posterior capsule is removed smoothly in a piecemeal fashion. C: The posterior capsular opening is expanded toward the periphery. D: The posterior capsule is completely removed, and no IOL dislocation or tilting is observed.

Figure 1: (continued)

Figure 1: (continued)

Figure 1: (continued)

Between December 1, 2006, and January 1, 2007, a consecutive series of 24 eyes in 24 patients with both vitreoretinal diseases and clinically significant cataracts was studied. Vitrectomy combined with cataract surgery using the described technique for a primary posterior capsulotomy had been performed in all patients. The mean age of the 13 women and 11 men was 64.3 years (range 43 to 74 years). The vitreoretinal diseases comprised proliferative diabetic retinopathy (6 eyes), rhegmatogenous retinal detachment (4 eyes), macular hole (4 eyes), epiretinal membrane (4 eyes), branch retinal vein occlusion (3 eyes), vitreous hemorrhage (2 eyes), and CME arising from nonproliferative diabetic retinopathy (1 eye) (Table 1). Informed consent was obtained from each patient. None had a history of trauma or ocular surgery. Postoperatively, the corrected distance visual acuity (CDVA), the presence of PCO, and the position of the IOL at 1, 3, 6, and 12 months were measured.

Table 1: Patient characteristics.

The mean CDVA improved significantly in all eyes, from a preoperative logMAR value of 0.55 to a value of 0.31 at 12 months (P = .01, t test) (Figure 2). Posterior capsule opacification had not occurred in any eye so an Nd:YAG laser posterior capsulotomy was not required during the 12-month follow-up. One eye (patient 7) with proliferative diabetic retinopathy exhibited IOL capture on postoperative day 1, but this condition disappeared by maintaining mydriasis and having the patient assume a prone position from day 2 onward. The optic was successfully repositioned in the bag. Intraocular lens dislocation or tilting was not observed in any eye during examination with a slitlamp microscope.

Figure 2: In all eyes that had a primary posterior CCC, the CDVA improved or maintained the preoperative value. At 12 months, the mean CDVA was significantly better than preoperatively (CDVA = corrected distance visual acuity).

DISCUSSION

Recent improvements in surgical technique and IOL technology have reduced the incidence of PCO formation and the need to perform Nd:YAG laser capsulotomy, but these complications have not been completely eradicated. In addition, previous studies^1,2 report that the PCO area may be larger in patients having a vitrectomy combined with cataract surgery than in those having cataract surgery alone because the combined surgery can lead to the development of severe postoperative inflammation. Several techniques to prevent PCO formation, primarily after cataract surgery, have been studied.

In the early 1990s, the forceps-created posterior CCC was popularized as a primary procedure for the prevention of PCO formation in adults.¹¹ In 1997, Gimbel¹² reported the clinical results of a procedure in which the IOL optic was buttonholed through a primary posterior CCC created using a microforceps in children. Menapace¹³ reported few complications in 1000 consecutive cases that had primary posterior CCC with posterior optic buttonholing. However, posterior optic buttonholing is a difficult procedure with a steep learning curve because it differs notably from conventional in-the-bag IOL implantation; surgeons may require dozens of cases to acquire the proper technique. It is uncommon to use primary posterior CCC and posterior optic buttonholing for a vitrectomy combined with cataract surgery.

We developed a technique for performing a primary posterior capsulotomy using a 25-gauge vitreous cutter. The technique is an extension of a conventional 25-gauge vitrectomy combined with cataract surgery. Therefore, it can be easily acquired and avoids the complications caused by inexperience. Because the 25-gauge vitreous cutter removes the posterior capsule smoothly and in a piecemeal fashion, the posterior capsulotomy using 25-gauge vitreous cutter may be as effective as primary posterior CCC. Using a 25-gauge vitreous cutter minimizes errors in the size of the posterior capsule opening.

In conclusion, our results show that a primary posterior capsulotomy using a 25-gauge vitreous cutter during a vitrectomy combined with cataract surgery is a safe and efficient technique for preventing PCO formation in patients with both vitreoretinal diseases and cataracts.