May 29, 2004
IOL Selection for the Weakened Capsular Bag
CRST May 2004
BY DAVID F. CHANG, MD
Because hydrophobic acrylic IOLs are associated with less anterior capsular fibrosis when compared with silicone lenses I believe that the former material is preferable for PXF eyes. Three-piece lens designs with broad, stiff PMMA haptics are able to exert the maximum centrifugal tension against the capsular fornices. They are preferable to the soft, floppy single-piece haptics for this reason. At the most recent AAO Annual Meeting, Da Reitz Pereira et al10 reported on a large ret-rospective study comparing the single-piece and threepiece AcrySof IOLs (Alcon Laboratories, Inc., Fort Worth, TX). With a single surgeon and identical capsulorhexis sizing, the single-piece AcrySof group demonstrated a significantly higher incidence of capsular contraction syndrome. Three percent of the single-piece AcrySof group required a YAG anterior capsulotomy for this condition versus none of the three-piece group. One should probably avoid silicone plate haptic IOLs in PXF eyes, because of these lenses’ haptic design and higher tendency for anterior capsular fibrosis.Finally, one should specifically examine the anterior capsular reaction at the final 1-month postoperative visit in patients with PXF. If there already are signs of early contracture and fibrosis, prophylactic YAG relaxing cuts in the capsulorhexis edge should be considered.Finally, one could place the IOL in the sulcus (Figure 2). The sulcus diameter can be estimated by adding 1.5 mm to the white-to-white horizontal corneal diameter. Thus, the typical foldable IOL of 13 mm in overall length is too short for a corneal diameter of 12 mm or greater. STAAR Surgical Company (Monrovia, CA) makes a 13.5-mm foldable silicone IOL (model AQ 2010 V) that is my preference for sulcus placement. The single-piece AcrySof is not only too short for sulcus placement, but it has thicker, sharpedged haptics that can cause pigment dispersion. If sulcus placement is elected because of a severe zonular dialysis, one should consider making multiple relaxing cuts the capsulorhexis edge to avoid extensive and asymmetric bag contracture with avulsion of the remaining hemisphere of weak zonules.
Posted by mehdi khanlari at May 29, 2004 09:35 PM