EyeWorld India March 2020 Issue

CORNEA EWAP MARCH 2020 37 by Chiles Samaniego EyeWorld Asia-Pacific Senior Staff Writer Contact information Goerlitz-Jessen: mark.goerlitz.jessen@duke.edu Hirst: lawrie@tapc.net.au Kim: terry.kim@duke.edu Lee: wblee@mac.com Mian: smian@med.umich.edu Rapuano: cjrapuano@willseye.org This article originally appeared in the November 2019 issue of EyeWorld . It has been slightly modified and appears here with permission from the ASCRS Ophthalmic Services Corp. C orneal abnormalities — mainly pathologies such as pterygium, Salzmann’s nodules, and epithelial basement membrane dystrophy (EBMD)— may be visually significant. “All of these conditions can impact the final visual outcome with cataract surgery, because they can affect the shape of the cornea and, as such, affect the measurements we need to accurately determine what lens implant the patient needs,” Shahzad Mian, MD, told EyeWorld . Managing these “lumps and bumps” is essential for optimizing refractive outcomes in cataract surgery. EyeWorld consulted various experts about handling these conditions. The impact of lumps and bumps W. Barry Lee, MD, shared a case to illustrate the impact of visually significant corneal abnormalities—particularly a pterygium—on cataract surgery. “Any time a corneal lesion (lump or bump) is found prior to cataract removal, consideration of how it affects the corneal topography and biometry is critical,” he said in an email. For a 75-year-old with pterygium who consulted for simultaneous pterygium excision and cataract surgery, Dr. Lee performed pterygium excision first and planned for cataract surgery 8–10 weeks later. On preoperative evaluation, the eye had 7.25 D of cylinder, with subsequent IOL calculations predicting a 24.5 D IOL for a plano postoperative refractive target. After pterygium excision, the eye had only 0.50 D of cylinder, with IOL calculations predicting a 20.5 D IOL for plano. “Without removing the pterygium first, I would have placed a 24.5 D IOL in the left eye,” Dr. Lee wrote. “Given the uncorrected vision was 20/20 uncorrected after pterygium surgery followed by cataract surgery 10 weeks later, the IOL would have been 4 D from target due to the induced astigmatism and incorrect K values on biometry.” Terry Kim, MD, and Mark Goerlitz-Jessen, MD, shared the case of a 75-year-old who underwent superficial keratectomy for Salzmann’s nodules (SNs) before undergoing cataract surgery 4 months later. In addition to undergoing biometric assessment prior to superficial keratectomy, the patient had three additional biometric assessments “to confirm an improved ocular surface and stable corneal parameters” between the two procedures (Figure 1). Final biometry prior to cataract surgery revealed an against- the-rule astigmatism of 1.08 D at 177 degrees—a significant change from the 1.28 D at 3 degrees measured preop. In this case, they selected a toric IOL, resulting in postoperative uncorrected distance visual acuity of 20/20 with a refraction of +0.50 – 0.25 x 92 (or +0.375 SE). “This case highlights the significant corneal changes induced by SN, the importance of managing these lesions prior to cataract surgery, and the success of toric IOLs in such cases,” they wrote. Assessing visual significance The cases presented clearly demonstrate that visually significant lumps and bumps need to be managed prior to cataract surgery, but their presence doesn’t always mean they are visually significant. These “lumps and bumps,” Dr. Mian said, can be chronic and stable, meaning they have no impact on the patient’s vision or corneal shape. “I think the number one priority, first, is to assess whether it is affecting the vision,” Dr. Mian said. “If it is affecting the vision and the shape of the cornea, then the second question is whether it has a stable effect or a changing effect. If it is stable, then we can choose to leave it alone after a good discussion with the patient.” To determine whether the pathology affects the corneal curvature and visual function, Christopher Rapuano, MD, wrote in an email to EyeWorld that he performs slit lamp examination to look for significant EBMD changes, subepithelial fibrosis, or Salzmann’s nodules within the central 6–8-mm optical zone; negative staining to identify elevation of the superficial layers particularly in the central 7–8-mm optical zone, probably indicating the AT A GLANCE • Visually significant lumps and bumps should be managed with enough time for the cornea to heal and stabilize prior to evaluation for cataract surgery with IOL implantation. • Premium IOLs can be used provided corneal abnormalities are adequately managed and a stable cornea is ensured; additional caution should be exercised when using toric IOLs in EBMD and patients should be counseled regarding the risk of recurrence. • MMC is helpful to prevent recurrent Salzmann’s nodules but is less useful for EBMD and must be used with extreme caution, if at all, for pterygium; a diamond burr is a useful adjunct for EBMD, but not essential, with alternative techniques available. Managing lumps and bumps: Paving the way to optimum cataract outcomes