Eyeworld

MAY 2012

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

Issue link: https://digital.eyeworld.org/i/78710

Contents of this Issue

Navigation

Page 22 of 67

December 2011 EW NEWS & OPINION 23 the bag. Because of this compressive rebound force, CTRs should never be inserted in the presence of an ante- rior or posterior capsule tear. Sec- ondly, the ring may impede cortical aspiration by pinning and trapping cortex in the capsular fornix. Surgeons can delay CTR insertion by instead using capsule retractors to continued on page 24 Figure 5. The capsule retractors stabilize the capsular bag against the decentering force of CTR implantation. The latter is delayed until after cortical cleanup has been completed Source (all): David F. Chang, M.D. fixating the capsular bag to the eye wall, capsule retractors will facilitate nuclear rotation and avoid creation of a zonular dialysis in the process. Capsular tension rings CTRs compensate for weakened zonules in several ways. With a focal zonular weakness or dehiscence, the ring redistributes mechanical forces (e.g., from nuclear sculpting or IOL insertion) to areas of stronger zonu- lar support. However, if the entire circumference of zonules is uni- formly weak, this benefit is lost. A second advantage is that centrifugal pressure applied by the ring makes the flaccid capsular bag tauter. This reduces redundant capsule folds, Pterygium continued from page 20 lation of the graft. • Harvesting a thin conjunctival autograft is best accomplished by making a small snip in the con- junctiva distal to the limbus, then lifting just the edge of conjunctiva (with minimal Tenon's fascia) using toothed forceps. Blunt Wescott scissors can be inserted parallel to the conjunctival surface and then opened in the plane just below the conjunctiva to separate away most of Tenon's. • The conjunctival autograft should not be significantly oversized or contain excessive Tenon's fascia, as these lead to excessive swelling after surgery. • At follow-up a small amount of gap at the nasal edge of the graft may occasionally occur. This does not increase risk of recurrence. EW References 1. Kenyon, KR. Conjunctival Autograft Trans- plantation for Advanced and Recurrent Ptery- gium. Ophth 92:1461, 1985. 2. Ma DH. Amniotic membrane graft for primary pterygium: comparison with conjunctival autograft and topical mitomycin C treatment. Br J Ophth 84:973, 2000. 3. Hovanesian JA, Behesnilian A. Results of Pterygium Excision Using Amnionic Membrane Beneath the Healthy Conjunctiva Surrounding a Conjunctival Autograft. Poster at American Society of Cataract & Refractive Surgery Symposium. Chicago, 2008. Editors' note: Dr. Hovanesian is clinical assistant professor, Jules Stein Eye Institute, University of California, Los Angeles. He has no financial interests related to this article. Contact information Hovanesian: jhovanesian@harvardeye.com 1293 Rev.B forward trampolining of the poste- rior capsule, and inward collapsing of the capsular fornices toward the aspirating instrument tip. The final benefit of a CTR is to counter pro- gressive contractile capsular forces post-op. Severe capsulophimosis is always a result of deficient zonular counter traction and is a likely factor in spontaneous late dislocation of the entire capsular bag in pseudoex- foliation. CTRs have two important disad- vantages. Significant compression is required to implant the ring into the capsular bag because of its larger size. This may stretch the capsu- lorhexis and potentially shear zonules by ovalizing or decentering .EW $ 0ARALLEL 4RAPEZOIDAL $IAMOND"LADES !DDITIONAL0RECISION7IDTHS 05-5081: 3-D Blade® 05-5082: 3-D Blade® 05-5083: 3-D Blade® 05-5084: 3-D Blade® , Angled Handle, 2.50mm Blade* , Angled Handle, 2.80mm Blade* , Angled Handle, 3.00mm Blade* , Angled Handle, 3.20mm Blade* 05-5086: 3-D Angled Trapezoid 2.50-3.50mm Blade* 05-5088: 3-D Angled Trapezoid 2.00-2.50mm Blade* 05-5091: 3-D Blade® 05-5093: 3-D Blade® 05-5096: 3-D Blade® , Angled Handle, 2.65mm Blade* , Angled Handle, 2.20mm Blade* , Angled Handle, 1.40mm Blade* 05-5097: 3-D Angled Trapezoid 1.20mm-1.40m Blade* 05-5099: 3-D Angled Trapezoid 1.00mm-1.20m Blade* 05-5101: 3-D Blade® &OR-ORE)NFORMATION 0LEASE#ALL , Angled Handle, 2.40mm Blade* 3360 Scherer Drive, Suite B, St. Petersburg, FL 33716 s4EL s 5 3 0ATENT.O 2% 6IRGIN%NTHRONED $A6INCI AJAJ s&AX %MAIL )NFO 2HEIN-EDICAL COMs7EBSITE WWW 2HEIN-EDICAL COM 05-5102: 3-D Blade®, Angled Handle, 1.8mm Blade* 05-5103: 3-D, Angled Trapezoid 1.75mm - 1.95mm Blade* 05-5104: 3-D Angled Angled Trapezoid 1.80mm - 2.20mm Blade*

Articles in this issue

Links on this page

Archives of this issue

view archives of Eyeworld - MAY 2012