![]() Ĭiliary process before and after ECP showing whitening and shrinkage Dispersive OVD such as Viscoat and Amvisc do not maintain space well and also have a tendency to absorb laser energy. ![]() Healon 5 would maintain space well but may increase the risk and severity of early postoperative IOP spikes. Other less cohesive OVD such as Provisc or Amvisc Plus may not be as reliable at maintaining the space in the ciliary sulcus well enough for ECP. A cohesive agent such as Healon or Healon GV may be the most advantageous OVD to use in this setting. To perform ECP, the anterior chamber must be stabilized and the ciliary sulcus must be deepened with an ophthalmic viscoelastic device (OVD). Topical, peribulbar and retrobulbar block techniques all provide acceptable anesthesia. However, an anterior vitrectomy must be performed if this approach is used. A pars plana approach can be considered in pseudophakic patients and provides the most complete view of the ciliary processes (see corresponding figure to the right). Both clear corneal and the scleral tunnel incisions commonly used in cataract surgery provide adequate access for the endoscope. ![]() The incision should be at least 1.5–2.2 mm in length. The limbal approach is generally recommended in patients undergoing ECP combined with cataract surgery and intraocular lens implantation (see corresponding figure to the right). Ciliary processes may be accessed from an anterior approach in phakic, pseudophakic, and aphakic eyes. Assessment of lens and vitreous status is important in determining an ECP surgical plan. With endoscopic cyclophotocoagulation, ciliary processes may be accessed from either a limbal or a pars plana approach. The light guide employs a 175 W xenon light source.ĮCP via a pars plana approach in a pseudophakic patient These three are available in an 18- to 23- gauge endoprobe with a 110° field of view and depth of focus from 1 to 30 mm. The laser endoscope has three fiber groupings: the image guide, the light guide, and the semiconductor diode laser guide, which is set to the 810-nm wavelength. The Uram unit has two basic sets of instrumentation: the laser endoscope and the equipment console. This was first reported in 1992 while using the endolaser to treat neovascular glaucoma. Uram developed an intraocular laser endoscope with both vitreoretinal and anterior segment applications. This technique was done using scleral depression through an operating microscope and not with an endoscope. Patel and colleagues were the first to report endolaser treatment of the ciliary body for uncontrolled glaucoma. They speculated that the partial return of blood flow may partially account for the lack of hypotony and phthisis with ECP as opposed to TSCPC. ECP also caused occlusive vasculopathy but there was partial reperfusion by 1 month. By contrast, ECP caused localized shrinkage of the ciliary process only. Lin and colleagues showed that TSCPC caused severe disruption of the ciliary process and the iris root and caused an occlusive vasculopathy out to 1 month. Histologic studies confirm that there is less tissue disruption with ECP than with transscleral cyclophotocoagulation (TSCPC). Traditionally, these procedures had been limited to patients with refractory glaucoma’s, usually as a last resort after failure of other surgical procedures.ĮCP affords the ability to apply cyclodestruction in a more targeted fashion directly to the target tissue, ciliary epithelium, while minimizing collateral damage. Complications include prolonged hypotony, pain, uveitis, hemorrhage, choroidal effusion, anterior segment ischemia, scleromalacia, failure and need to retreat, and postoperative visual loss associated with chronic cystoid macular edema. ![]() Prior to ECP, cyclodestructive procedures involved the surgeon attempting to ablate the ciliary tissue with limited ability to assess anatomic accuracy or qualitative effect. Various attempts at decreasing intraocular pressure via cyclodestruction share a common set of disadvantages and complications. Since that time, cyclophotocoagulation through either a trans-pupillary route or a contact or non-contact trans-scleral route has been popularized utilizing a multitude of different lasers. ![]() In the 1960’s, Purnell advocated a trans-scleral ultrasound radiation to produce the desired destruction. Cyclodestruction as a method to treat glaucoma was first observed by Heine when he discovered that detachments of the ciliary body resulted in decreases in intraocular pressure. ![]()
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |