Four ports pars plana vitrectomy in retrieving dislocated posterior chamber intraocular lens

    作者：Lei Gao, Fu-Hua Wang, Ying Sun   

    作者单位：Department of Ophthalmology, Yantai Yuhuangding Hospital, Affiliated Hospital of Medical College, Qingdao University, Yantai 264000,Shaanxi Province China

    【摘要】AIM: To report the use of modified four ports pars plana vitrectomy in managing a dislocated posterior chamber intraocular lens.

     METHODS: A young man with bilateral pseudophakia and dislocated PC-IOLs had undergone modified four ports pars plana vitrectomy in relocating a dislocated posterior chamber intraocular lens. This procedure was surgically less tedious and demanding compared with previous methods of IOL retrieval.

    RESULTS: No significant intra- or post-operative complication was noted. The visual recovery of the operated eye was rapid with the best corrected visual acuity at 14 months post-operation being 0.5. In contrast, the right eye without operation due to patient refusal developed total retinal detachment with hand movement visual acuity.

    CONCLUSION: Modified four ports pars plana vitrectomy may be a more ophthalmic surgeon friendly alternative in the retrieval of dislocated IOL.

    【关键词】  modified ; four ports pars plana vitrectomy；retrieval of dislocated IOL

    INTRODUCTION

    Dislocation of intraocular IOL implants into vitreous is one of the major complications in cataract surgery. It had been estimated that 0.2% to 1.8% of patients develop IOL dislocation after cataract surgery and projected increasing incidence was anticipated with widespread use of phaecoemulsification.[1] Removal of the dislocated hard-IOLs from the vitreous is surgically demanding with set-backs associated with sizable limbal incision such as suprachoroidal hemorrhage, iris prolapse, endothelial damage and increased infective risk.[2] Various surgical techniques about IOL repositioning have been proposed in tackling this controversial issue.[2-5] We would like to report an innovative four ports pars plana vitrectomy in retrieval of dislocated IOLs in the left eye of a young man who as a contrast, suffered from dislocated IOL related total retinal detachment in the fellow eye.

    CASE REPORT

    In Oct 2001, a 38-year-old man presented with loss of vision 3 days after a bicycle accident related blunt trauma to his left eye. He had undergone uncomplicated right extracapsular cataract extraction (ECCE) and posterior chamber IOL (3-pieces PMMA) implantation in 1990. Unexpectedly, there was IOL dislocation into the right vitreous 3 months after the cataract operation. He refused any surgical intervention. In 1996, he received similar cataract operation and IOL implantation in his left eye, and he had to rely solely on his pseudophaic left eye prior to this traumatic event. After all, no clinical evidences were apparent to account for cataracts in such young patient.

    On examination, visual acuity was 0.04, correctable to 0.5 in each eye. Iridodonesis and large posterior capsule ruptures were noted bilaterally. The dislocated IOLs of both eyes moved freely within the detached and liquified vitreous humor. Apart from mild myopic maculopathy, neither retinal detachment nor retinal break could be found by indirect ophthalmoscope examination.

    A modified 4-port pars plana vitrectomy (Figure1) was performed 2 days after admission in repositioning left dislocated IOL. After completing pars plana vitrectomy through incision A, intraocular forceps was passed through site A, and one haptic of IOLs was grasped, brought anteriorly and held in the center of the cavity. A pre-made slipknot loop of a double-armed 10-0 Prolene was inserted with another forceps through incision D by the assistant, and the contralateral haptic was looped internally (Figure 2). The Prolene suture was drawn tightly to ensure the haptic snugged against the sclera. The two free ends of the Prolene suture were tied under the scleral flap. The procedure was easily repeated in the other side by the surgeon and sutures were fixed at site A (Figure 3). Incision B was used for final inspection of peripheral retina. No complications occurred during the procedure. Unfortunately, due to financial reason, he refused to our suggestion of repositioning his right dislocated lens in the same way.

    Figure 1 To simplify the diagram, the triangular scleral flap at site A and D are not shown. Two sclerotomies A and D, 1.5 mm posterior to the limbus and 180 degrees away, are used to center the lens. Both site B and site C are 3.5 mm posterior to the limbus

    Figure 2 One haptic of IOL is grasped and held in the center of the vitreous cavity. The contralateral haptic is looped internally with another forceps through incision D by the assistant

    Figure 3 The suture (Site C) is drawn tightly to ensure the haptic snugged against the sclera. The free haptic is looped internally with forceps through incision D by surgeon

    About 6 months after the surgery, he presented to us with right eye total retinal detachment. Slit-lamp examination revealed one end of haptic of dislocated IOLs intruded into the anterior chamber and its optic embedded within the funnel-shaped detached retina. Fourteen months after the left IOL repositioning surgery, the IOL remained stable and well centered with best-corrected visual acuity of 0.5.

    DISCUSSION

    IOL dislocation may occur in the absence of appropriate capsular or zonular support or following traumatic injury to anterior ocular tissues. An array of management strategies consisting of observation, IOLs exchange, IOLs repositioning and IOLs removal had been described in relation to different clinical context and individualization.[1] There was a report that dislocated IOLs could remain in the vitreous for as long as 6 years without serious complications.[6] However, repositioning of dislocated IOLs is becoming more manageable because of the advancement of surgical techniques.

    Scleral fixation technique is a popular way of refixating dislocated implants, and several techniques have been described. [2-5] Our modified technique allows better visualization during the placement of slipknot loop around the first haptic. Similar procedure can be technically easily accomplished for the second haptic. More importantly, we can make final inspection, or endolaser if necessary for the peripheral retina through incision B at the end of the surgery without damage to the haptics or sutures by the probe. Advantages of 4-port pars plana vitrectomy are as follows: (1) No limbus incision is needed, which may avoid the odds of astigmatism and speed up visual recovery; (2) As the suture is placed with forceps and at place far away from retina, the iatrogenic damage made to the retina is minimized; (3) The dislocated IOL may be reused and no Perfluorocarbon liquid is necessary, both of these measures will reduce the cost of surgery.

    The clinical presentation in our patient was a rarity for dislocated IOLs remaining in vitreous cavity as long as 11 years without any serious complications until October, 2002. Disparity in visual outcomes between intervened and observed eyes with dislocated IOLs for the same patient might favor the option of early repositioning. It seemed that dislocated IOLs in the vitreous cavity always posed constant threat to the retina even in face of many years of quiescence. With increase in life expectancy, conservative treatment might not be a good option especially in young patients engaging in strenuous physical exertion and with anticipated prolonged implant-retinal contacts.

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