Eyeworld

EW INTERNATIONAL 120 October 2016 by Stefanie Petrou-Binder MD, EyeWorld Contributing Writer Enucleation and evisceration technique modifications improve implant motility and reduce extrusion risk E nucleation and evisceration are implemented when a diseased or damaged eye necessitates removal due to blindness accompanied by pain, severe infection, or tumor. Beyond the medical exigency of these procedures, once the diseased globe is removed, the focus of treat- ment is to provide the patient with a cosmetically acceptable appear- ance. According to Artur Klett, MD, head of the eye clinic, East Tallinn Central Hospital, Tallinn, Estonia, who spoke on enucleation and evisceration at the Ophthalmologi- cum Balticum Congress, while both procedures are synonymous with the irreversible loss of eye function, clever modifications in these surger- ies have greatly improved implant motility and eye symmetry, while reducing the risk of extrusion. What's the difference? Enucleation removes the intact diseased globe and its contents, with preservation of the periorbital and orbital structures. Primary enucle- ation is carried out in drastic cases of known or suspected intraocular ma- lignancies, allowing the histologic examination of the intact globe and optic nerve for the extent of tumor invasion. In evisceration, the ocular con- tents are removed while preserving the scleral shell and the extraocular muscle attachments. The most com- mon indication for evisceration is a blind painful eye or in cases where endophthalmitis is unresponsive to antibiotics. Although sympathetic ophthalmia (SO) has been histori- cally associated with evisceration, a review of the literature reveals SO to be a rare consequence of eviscera- tion. Many ocularists have come to prefer evisceration to enucleation in patients requiring eye removal due to better prosthesis motility and the superior overall cosmetic outcomes, thanks to steady advances in surgery and improved implant materials. "It is common for ophthalmol- ogists to feel mainly responsible for maintaining or restoring vision," Dr. Klett said. "Enucleation surgery was often regarded as a simple procedure, often performed as a surgical training exercise for young ophthalmolo- gists. This has changed since orbital implant surgery has been proven to be safe and effective in the hands of trained eye surgeons. In the past 100 years, there has been continued im- provement in the surgical techniques of enucleation and evisceration, and in the methods of rehabilitating the anophthalmic eye socket. Mean- while, recent decades have brought much progress in implant material, all contributing to excellent out- comes in artificial eye appearance, placement, and motility." Modified evisceration technique Evisceration removes the internal contents of the eye and is associated with a limitation in the orbital im- plant size when performed tradition- ally. Surgeons today, however, bene- fit from long years of experience and numerous publications on eviscer- ation, with surgical improvements owing largely to small but meaning- ful modifications. Dr. Klett described a modified evisceration procedure Meeting the cosmetic demands of anophthalmia that has overcome implant size limitations, creating eyes with increased, more natural motility, by combining scleral modification with optic nerve release. The scleral modification tech- nique is used to expand the sclera and enlarge the space for the im- plant, releasing the scleral flaps from their optic nerve attachments, while connecting the artificial eye with the remaining ocular structures. "Scleral modification is an innovation of the traditional evisceration technique that fulfills our two main goals: to replace the lost volume with a larger, well-fitted implant and to achieve maximum implant motility. The modified evisceration technique involves the use of sclerotomies that expand the scleral shell and the use of fixation sutures that come between the implant and the shell to additionally reduce tension on wound healing," he explained. Sclerotomies ease the tension on the sclera, allowing the placement of larger implants, which reduces the likelihood of extrusion and helps improve the sunken-in effect of too- small implants. "The evisceration procedure permits the use of a large implant, even when the cornea is removed," Dr. Klett said. "According to a recent study, there is a signifi- cant incidence of implant extrusion after traditional evisceration sur- gery. 1 It also minimizes the possibili- ty of implant migration or extrusion thanks to secure, tension-free ante- rior wound closure. The technique uses the imbrication of the anterior scleral flaps to enhance the strength of the closure around the implant." Modified enucleation technique Traditional enucleation removes the entire globe. Patients with malig- nancies necessitating this more drastic surgery now also profit from a more innovative approach to this procedure. According to Dr. Klett, the creation of muscle pedunculated scleral flaps permits much better implant motility. "The advantage of creating muscle pedunculated scleral flaps in combination with hydroxyapatite implants is the creation of a joint- like structure at the posterior part of the implant. Fully vascularized scleral tissue covers the anterior part of the implant that is still attached to its natural blood supply through Modified evisceration technique using muscle pedunculated scleral flaps Source: Artur Klett, MD

• Cover