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+ Larger Font / - Smaller Font WTRC Newsletter Volume 1 Issue 3 January 16, 2006 Retinal Detachment By S. Young Lee, M.D. Retinal detachments occur in approximately 1 in 10,000 people per year.¹ Prior to the 20th century, retinal detachment repair was often unsuccessful. However, with modern vitrectomy and scleral buckle techniques roughly 95% of all rhegmatogenous retinal detachments can be repaired.² In this issue of our newsletter we will share some of our experiences in the treatment and management of this potentially blinding condition. Retinal detachments can be classified as tractional, exudative, or rhegmatogenous. We will focus on rhegmatogenous retinal detachments or RRD. A RRD develops from a full thickness retinal tear. Outside of trauma, this often happens from an acute posterior vitreous separation. Vitreous that is firmly adherent to peripheral regions of the retina can contract with age forming a retinal tear. Through this tear, liquefied vitreous rushes into the subretinal space and accumulates behind the retina resulting in a RRD. This is analogous to having a tear in the wallpaper and watching fluid rush in through the tear and accumulate behind it causing the wall paper to separate completely from the wall. Once a signifcant amount of fluid has accumulated, office laser is ineffective in sealing the break. This leaves us with three primary modalities in the treatment of a RRD namely pneumatic retinopexy, scleral buckle, and pars plana vitrectomy with or without scleral buckle. Pneumatic retinopexy has the distinct advantage in that it can be performed in the office. It involves intravitreal gas injection combined with postinjection positioning and laser photocoagulation. The ideal candidate for a pneumatic retinaopexy is a phakic patient with a break less than one clock hour located superiorly between 8 and 11 o'clock and 4 o'clock without significant proliferative vitreoretinopathy (PVR). Scleral buckling was once considered the gold standard for retinal reattachment surgery with success rates of 82-91% for a single operation.³ This procedure involves isolating each of the rectus muscles and placing a buckling element (we prefer soft buckling elements known as sponges) underneath the muscles to indent the external sclera to relieve internal traction (Figure 1). This can be combined with external drainage of the subretinal fluid by making an incision in the bed of the buckle outside of the eye. Laser photocoagulation can be administered after the fluid has been drained to surround the tear. In some cases, an intraocular gas bubble can be placed to expedite reabsorption of subretinal fluid followed by laser in the office. Although some surgeons now favor primary vitrectomy for most RRD cases, scleral buckling is still very effective in repairing a RRD in phakic patients and those with significant PVR without having to enter the eye with instruments.
Recently there is an increasing trend towards performing primary vitrectomy for the repair of routine retinal detachments. Modern vitrectomy has allowed for enhanced capability of identifying small previously unrecognized tears and removing tractional PVR membranes. This procedure involves placing three ports in the sclera through the pars plana: one port for an infusion to keep the eye inflated during surgery, a second port for a light source, and the third port for manipulation devices such as the vitrector, laser, or forceps (See Figure 2). Following removal of the vitreous, the subretinal fluid is drained internally to flatten the retina and laser is administered to seal the instigating retinal tear. A gas bubble such as SP6 or C3F8 is combined with postoperative postioning (usually for one week duration) to support the retina to give time for the laser burns to heal.
As an aside, the importance of head down positioning can not be overemphasized since fluid will reaccumulate causing failure of the surgery. It is also important to remind your patients with gas bubbles that they should avoid high altitude activities such as flying or mountain climbing as well as procedures using inhaled anesthetics, since these activities can cause the bubble to painfully expand in the eye. Each of these three surgical techniques has their advantages and disadvantages which has led to some controversy regarding the ideal procedure for primary retinal detachment. In our own practice, we favor primary scleral buckling over vitrectomy in the younger phakic patient to avoid cataract formation. However, scleral buckling can induce myopia and diplopia. Primary vitrectomy is useful in those eyes with vitreous hemorrhage, posterior retinal breaks, giant retinal tears, and established PVR. We have retrospectively looked at our own surgical results of a contiguous 7 month period in the past year involving 30 RRD cases. In this group, 73% of patients had stabilized or increased visual acuity with at least 2 months follow up. Interestingly, 33% of patients had final pinhole visual acuities of greater than 20/50. All 30 patients were successfully reattached during this period in comparison to the reported rate of 95% mentioned at the beginning of this article. We hope that this article has helped demystify some of the techniques currently used to repair retinal detachments. In any case, we stand ready to meet the current and future needs of your patients with proven techniques and the promise of new therapies to come. Special thanks to Tiffany Hardin, COA and Brenda Ziegler, FNP for their help in the preparation of this manuscript. ¹ Wilkes SR, Beard CM, Kurland LT, et al. The incidence of retinal detachment in Rochester, Minnesota, 1970-1978, Am J Ophthalmol. 1982;94:670-673. ² Af-Fat FG, Sharma MC, Majid MA, et al. Trends in vitreoretinal surgery at a tertiary referral center; 1987 to 1996. Br J Ophthalmol 1999;83:396-398 ³ Schwartz SG, Kuhl DP, McPherson AR, et al. Twenty-year follow-up for scleral buckling. Arch Ophthalmol 2002;120:325-329. Figure 1: Medical Illustration Copyright © 2005 Nucleus Medical Art, All rights reserved. www.nucleusinc.com Figure 2: Medical Illustration Copyright © 2005 West Texas Retina Consultants, PA. West Texas Retina Consultants Sunil S. Patel, M.D., Ph.D. S. Young Lee, M.D. 5441 Health Center Drive Abilene, Texas 79606 800-810-7411 325-673-9806 info@westtexasretina.com |
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