EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/129516
May 2013 EW RESIDENTS 57 EyeWorld journal club Review of "Comparison of posterior capsular opacification and glistenings with 2 hydrophobic intraocular lenses: Five- to seven-year follow-up" by Kimberly M. Hsu, MD, Sarah M. Jacobs, MD, Courtney L. Kraus, MD, Gokul N. Kumar, MD, Tahira Mathen, MD, Linda M. Tsai, MD, and Susan M. Culican, MD, residency program director, Washington University School of Medicine Introduction Susan M. Culican, MD, residency program director, Washington University School of Medicine An article in this month's JCRS compares the rates of PCO and glistenings between different models of hydrophobic acrylic IOLs. I asked the Washington University (St. Louis) residents to provide the review of this study. David F. Chang, MD, chief medical editor Intraocular lens (IOL) placement at the time of cataract surgery is the standard of care in modern ophthalmology. Many factors must be weighed when determining which IOL to implant, including the refractive goal, lens design, and lens material. As most patients maintain their IOL in place throughout the remainder of life, how the lens will behave within the eye over time must also be taken into consideration. In this month's JCRS, Chang et al. report their findings on "Comparisons of posterior capsular opacification and glistenings with 2 hydrophobic intraocular lenses: Five- to seven-year follow-up." This study is of interest because long-term follow-up data about posterior capsular opacification (PCO) and glistenings can help inform IOL selection, and thus potentially improve patient outcomes. PCO is Handling continued from page 56 ing, I immediately place a cotton tip over the broken blood vessel and apply direct pressure. Yes, right back to the principles of first aid! I hold the applicator over the area to tamponade the bleeding. If that doesn't work, I use cautery to close the ruptured blood vessel if I can see it. While the case described above is rare, I do like to stop even small SCH because patients do not like the postoperative appearance and will often feel that something went wrong with their surgery despite their good vision and our reassurance that this is benign. When significant chemosis occurs, this can distort the surgeon's view. The most common cause of this is a corneal wound that is too posterior, nicking the conjunctiva and allowing fluid from the phacoemulsification probe to egress under the conjunctiva and causing it to balloon up. In this case, this chemosis occurred due to the extensive SCH. If the view is significantly distorted, I will make an incision in the conjunctiva to decompress the chemosis. This is best done in a nonexposure area of the bulbar conjunctiva. I once had a patient who developed a small fleshy scar in the area of the conjunctival cut, so now I always do this in a non-visible area. Prevention I do try to have a patient stop all blood thinners, if possible. Even though the risks are low with topical anesthesia, it is always safer to stop. If the primary physician or cardiologist says no, then at least the patient knows we tried and accepts the small risks. My preferred stabilization instrument is a fixation ring, but as seen in this case, one of the tiny "feet" can rarely break a blood vessel. For these reasons, in these cases I prefer to use a cotton tip or hold the paracentesis when stabilization is needed. EW Editors' note: Drs. Chopra, Karp, and Mian have no financial interests related to the article. Contact information Chopra: vikchoprausc@gmail.com Karp: ckarp@med.miami.edu Mian: smian@med.umich.edu known to cause suboptimal postoperative visual acuity. Although PCO is treatable with Nd:YAG capsulotomy, preventing its occurrence by optimizing intraocular lens design and material choice may reduce healthcare costs and decrease complications from a secondary procedure. IOL glistenings are known to increase in certain lenses with time, but have an unknown clinical significance.1 Prior studies of the visual impact of glistenings have had discordant results, with one group finding that glistenings significantly decrease contrast sensitivity while another reported such an effect only at high spatial frequencies.2-3 A third group found no significant correlation with contrast sensitivity, but felt that the visual effect could become significant over time as more glistenings develop in the lens.4 Improved understanding of the clinical effect of glistenings is needed. Study summary Chang and colleagues aim to assess the occurrence rates of PCO, as well as the frequency and visual significance of glistenings via a comparison of two different hydrophobic acrylic lenses at 5-7 years after implant placement. Their study is a prospective, randomized study of 80 patients without significant ocular comorbidities who underwent uncomplicated cataract extraction and IOL insertion within a designated two-year time period. continued on page 58 Comparison of posterior capsule opacification and glistenings with 2 hydrophobic acrylic intraocular lenses: Five- to seven-year follow-up Anthony Chang, MD, Anders Behndig, MD, PhD, Margrethe Rønbeck, MD, Maria Kugelberg, MD, PhD J Cataract Refract Surg (May) 2013; 39:694-698 Purpose: To compare posterior capsule opacification (PCO) and glistenings 5 to 7 years after cataract surgery with implantation of 2 hydrophobic acrylic intraocular lenses (IOLs) and evaluate the effects on corrected distance visual acuity (CDVA) and contrast sensitivity. Setting: St. Erik Eye Hospital, Stockholm, Sweden. Design: Randomized clinical trial. Methods: Cataract surgery with standard phacoemulsification was performed in 1 eye of patients. The patients were randomized to an AcrySof SA60AT (1-piece IOL group) or a Sensar AR40e (3-piece IOL group), both hydrophobic acrylic IOLs with a sharp-edged design. Five to 7 years postoperatively, retroillumination images were obtained and the PCO area and severity (area affected within the capsulorhexis and severity) were evaluated using computer software. High-contrast (100%) and low-contrast (2.5%) CDVAs were measured. The neodymium:YAG laser capsulotomy rates were recorded. Scheimpflug images were obtained to evaluate glistenings, which were graded subjectively at the slit lamp and quantified objectively by digital image analysis using computer software. Results: The study enrolled 80 patients. There were no significant differences in PCO between the 2 IOLs. The 3-piece IOL group had significantly fewer glistenings (P<.001). There was a good correlation between the subjective grading of glistenings and objective computer-processed image grading. The glistenings were not correlated with IOL power, CDVA, or contrast sensitivity. Conclusions: There were no significant differences in PCO between the 2 acrylic hydrophobic IOLs 5 to 7 years postoperatively. The 1-piece IOL group developed more glistenings than the 3-piece IOL group. Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.