Technique for removal of a capsular tension ring from the vitreous

Technique for removal of a capsular tension ring from the vitreous

Technique for Removal of a Capsular Tension Ring from the Vitreous Patrick E. Ma, MD, FRCSC, Harrup Kaur, MD, Velimir Petrovic, MD, Dawn Hay, BSN Purp...

151KB Sizes 0 Downloads 2 Views

Technique for Removal of a Capsular Tension Ring from the Vitreous Patrick E. Ma, MD, FRCSC, Harrup Kaur, MD, Velimir Petrovic, MD, Dawn Hay, BSN Purpose: To report a new technique for safely and quickly removing a displaced capsular tension ring from the vitreous cavity. Design: Two interventional case reports. Participants: The authors retrospectively reviewed the charts of two patients with displaced capsular tension rings (CTRs). Intervention: Surgical removal of the displaced CTRs was performed in two patients. Main Outcome Measures: Visual and anatomic outcomes. Results: The CTRs were removed surgically, in case 1 by cutting the CTR into two pieces before removal and in case 2 by using the CTR injector to remove the CTR in one piece through a sclerotomy site. Both patients had good visual and anatomic outcomes. Conclusions: The described technique of removing a displaced CTR in one piece through a sclerotomy site using the CTR injector provides a safe and efficient method of CTR removal. Cutting the CTR into two or more pieces for removal is not recommended. Ophthalmology 2003;110:1142–1144 © 2003 by the American Academy of Ophthalmology.

Since its initial prototype was introduced in 1991 by Hara et al,1 the capsular tension ring (CTR) has become a useful tool in providing stabilization of the capsular bag in cases of zonular dehiscence or weakness. Several versions of the capsular tension ring have been made, including the polymethyl methacrylate (PMMA) CTR by Morcher GmbH (Stuttgart, Germany), the PMMA CTR by Ophtec (Groningen, The Netherlands) and the ReFORM CTR by Alcon (Fort Worth, TX). The most commonly used design is an opentype ring with eyelets at either end2 (Fig 1). This CTR can be inserted into the capsular bag either with forceps or with a CTR injector (Fig 2) (Geuder G-32960 injector for the Morcher CTR and the Ophtec Easy Control Micro Inserter for the Ophtec PMMA CTR). These rings are usually placed into the capsular bag without incident. A technique of introducing a suture through one of the eyelets during insertion has been described to allow the leading edge to be pulled centrally, facilitating placement, or to allow removal while the ring is still in the anterior chamber.2 However, given their usefulness in cases of capsular instability, potential complications must be anticipated. Perforation and displacement through the capsular defect may occur, or the entire capsule with the CTR can dislocate posteriorly, posing a challenge for the surgeon.2 Because of their substantial diameter, they must be either removed through the anterior chamber or cut into

Originally received: April 22, 2002. Accepted: October 31, 2002. Manuscript no. 220289. From the Department of Ophthalmology, University of British Columbia, Vancouver, B.C., Canada. Reprint requests to Patrick Eugene Ma, MD, Vancouver Hospital. Eye Care Centre, 2550 Willow Street, Vancouver, B.C., V5Z 3N9, Canada.

1142

© 2003 by the American Academy of Ophthalmology Published by Elsevier Inc.

multiple pieces to facilitate removal through a pars plana sclerotomy during vitrectomy. The authors have performed two cases of CTR removal. In the first, the ring was cut into multiple pieces. In the second, a new technique was used that allowed safer, more rapid removal of the CTR.

Case Reports Case 1 An 80-year-old male was referred for removal of a posteriorly dislocated crystalline lens in the left eye after cataract extraction surgery. His ocular history was significant for pseudoexfoliation glaucoma in the left eye. At presentation, ocular examination revealed visual acuity of 20/30 in the right eye and hand motions in the left eye and intraocular pressures of 18 mmHg in the right eye and 44 mmHg in the left eye. In the left eye, the cornea was edematous and blood stained, the anterior chamber had 2⫹ white blood cells and 2⫹ red blood cells. The posterior capsule was ruptured with no lens in situ, and inflammatory cells were visible in the anterior vitreous. Fundus examination of the left eye revealed significant vitreous haze and a cup-to-disc ratio of 0.8. The inferior retinal view was obstructed by the dropped lens, with some chorioretinal atrophy visible inferotemporally. The patient underwent a standard pars plana vitrectomy. Intraoperatively, the capsular bag containing the crystalline lens and a Morcher PMMA CTR was hung from the inferior vitreous. The vitreous connections to the lens-capsule-ring apparatus were severed with the ocutome, allowing it to float to the posterior pole while the vitrectomy was completed. After removal of the capsule and lens by fragmentation, the horseshoe-shaped PMMA Morcher ring was grasped with the Dutch Ophthalmic Research Center (DORC) forceps and elevated to the pupillary space. Despite extending the corneal wound to 6.5 mm, the CTR could not be removed in its entirety because of its diameter. The ring was cut ISSN 0161-6420/03/$–see front matter doi:10.1016/S0161-6420(03)00332-4

Ma et al 䡠 Capsular Tension Ring Removal

Figure 1. Capsular tension ring.

into two pieces with DORC intraocular scissors, allowing each piece to be removed separately. The posterior chamber intraocular lens (IOL) was sutured into place and the wound closed. The peripheral retina was examined by means of indirect ophthalmoscopy. No retinal holes or tears were noted; however, significant corneal edema afforded a limited view. The sclerotomies and conjunctiva were closed, and subconjunctival antibiotics and steroid were injected. The patient was seen 1 month later with a macula-on rhegmatogenous retinal detachment in the left eye. A small horseshoe tear at the 12 o’clock position was repaired with a pars plana vitrectomy and scleral buckle without difficulty. Visual acuity 5 years after CTR removal was 20/30 in the right eye and 20/150 in the left eye, with an attached retina and glaucomatous optic nerve damage.

Case 2 An 83-year-old female was referred for a dislocated nucleus and Alcon ReFORM CTR in her left eye during cataract extraction surgery. She had a history of cataract extraction in the right eye complicated by pseudophakic bullous keratopathy necessitating a

corneal graft. Visual acuity at presentation was 20/30 in the right eye and hand motions in the left eye. Anterior segment examination disclosed a clear graft cornea in the right eye and an anterior chamber IOL with copious cortex in the left eye. On indirect ophthalmoscopy, a normal posterior pole was seen in the right and a dropped nuclear fragment in the inferior vitreous cavity on the left. A small inferior retinal hole was also found in the left eye at the 6 o’clock position. A standard three-port pars plana vitrectomy was performed, with removal of the dropped lens in its entirety with a combination of a fragmatome and cutter. After this, the CTR was tilted with DORC forceps to allow visualization of the ring’s eyelet. A microvitreoretinal blade was used to marginally widen the sclerotomy, through which a Geuder CTR injector was inserted. The plunger of the injector was depressed, projecting the hook of the injector (Fig 3). The hook was then placed through the eyelet of the CTR and slowly retracted while the CTR was removed from the eye in a single motion. Air–fluid exchange was then performed and endolaser completed around the inferior retinal hole. Scleral depression examination for 360° revealed no evidence of retinal holes, tears, dialysis, or detachments. The sclerotomies and con-

Figure 2. Geuder forceps for capsular tension ring.

1143

Ophthalmology Volume 110, Number 6, June 2003

Figure 3. Capsular tension ring withdrawn inside of Geuder forceps.

junctiva were closed, subconjunctival antibiotics and steroid were injected, and atropine drops were instilled. At 3 months follow-up, the patient’s best-corrected visual acuity was 20/30 in the right eye and 20/25 in the left eye, with no retinal abnormalities.

Discussion CTRs are large in diameter, preventing them from being removed through a sclerotomy site in one piece. In case 1, the CTR ring was cut into fragments to facilitate removal; however, this presented the risk of having “swords” in the eye that could easily have caused damage. Cutting the CTR into multiple pieces also necessitates multiple, technically difficult retrievals of each dissected portion from the posterior pole. We have found that the technique described in case 2, using the ring injector to carefully remove the CTR in one piece, is a safe and controlled alternative, minimizing potential risk and reducing operating time. It was noted during this second procedure that while the ring is being removed, the portion remaining outside the injector retains its curved profile, thereby minimizing risk of retinal dam-

1144

age. In addition, the preceding technique does not disturb the anterior chamber, permitting a well-placed IOL to be left undisturbed. Of note, in cases of dislocation of the entire capsule or IOL and CTR, or in the presence of a macula-on retinal detachment with CTR dislocation, perfluoro-N-octane could be considered to protect the posterior pole. In planning the removal of a CTR, the surgeon should first consider the type of ring placed at the initial surgery. Other, less common types of rings can be inserted, including models for partial iris defects or aniridia, which may not be amenable to removal by this method. In both cases presented here, open-type rings with eyelets were removed, a style well suited for the removal technique described.

References 1. Hara T, Hara T, Yamada Y. “Equator ring” for maintenance of the completely circular contour of the capsular bag equator after cataract removal. Ophthalmic Surg 1991;22:358 –9. 2. Menapace R, Findl O, Georgopoulos M, et al. The capsular tension ring: designs, applications, and techniques. J Cataract Refract Surg 2000;26:898 –912.