Eyeworld Daily News

8 | EYEWORLD DAILY NEWS | MAY 17, 2020 DAILY NEWS ASCRS VIRTUAL ANNUAL MEETING continued on page 10 Keratoconus: diagnosing, monitoring progression, and considerations for cataract surgery He started by introducing keratoconus as a noninflamma- tory thinning of the cornea. It's characterized by thinning of the corneal stroma with disrup- tions of Bowman's membrane, Dr. Ayres said. This leads to progressive myopia and astig- matism and is still one of the most common indications for corneal transplantation, though with decreasing incidence. A lot of the focus with kerato- conus is on the young patient and prevention of progression, he added, due to the advent of corneal crosslinking. But as there are less patients having corneal transplants and as keratoconus patients get older, those patients will eventually need cataract surgery. So how do physicians tackle that and troubleshoot the patient with keratoconus and lens changes? Dr. Ayres presented several questions to address: • When are the lens changes clinically significant? • What formula should I use to calculate lens power? • When is it appropriate to place a toric IOL? • Should this be combined with a corneal procedure? 8 months after treatment, the Kmax was down to 65.7 and the ABCD reading was 4,4,2. Uncorrected vision was 20/30 and best-corrected vision was 20/25. The final case was a 14-year-old female patient who presented with a Kmax of 52.6, ABCD reading of 2,3,2, and best-corrected vision of 20/20. She underwent crosslinking. Dr. Beckman said this case demonstrates long-term results from crosslinking because 3 years postop, the patient's Kmax was down to 50.3, ABCD reading was 2,4,2, and best-corrected vision was still 20/20. In summary, Dr. Beckman said making the diagnosis is critical, and a number of factors including history, clin- ical findings, and topography and tomography can be used. There's no single parameter that has all the answers, and it's critical to check both eyes to look for asymmetry. He said don't forget to use the new formulas and don't forget the difference map, which is great for monitoring progression. Brandon Ayres, MD, Philadelphia, Pennsylvania, discussed cataract surgery in keratoconus. • Truncated bowtie • I-S (inferior to superior) difference • Asymmetry within the cornea and between eyes • Posterior elevation • Pellucid marginal degener- ation (sagging bowtie, crab claw, or bell sign) Dr. Beckman shared a few case presentations, the first of which was a 28-year-old male who presented with a Kmax of 53.4 (moderate cone) and had an ABCD reading of 2,2,1. His visual acuity was not bad, but he declined crosslinking. After 6 months, the patient was still stable with a Kmax of 53.3 and ABCD reading of 2,2,1, howev- er, Dr. Beckman noted that the uncorrected vision was starting to drop, though the patient again declined crosslinking. The patient came back 10 months later with a Kmax of 55.1 and ABCD reading of 2,3,2. There was progression on the topography, but the pa- tient still declined crosslinking. Using a difference map, Dr. Beckman said obvious pro- gression was shown, and this is a patient who would really benefit from crosslinking. He shared a case of a 17-year-old male who present- ed at the initial visit with a very severe cone with a Kmax of 67.5 and an ABCD reading of 4,4,3. Uncorrected vision was 20/100 and best-corrected vision was 20/60. The patient was sent to Dr. Beckman for a second opinion because he was told he needed a transplant, but although the patient's cornea was steep, it was clear, and the patient underwent crosslinking 2 months later. Dr. Beckman said he likes to give these patients the opportunity to have crosslinking first (and perhaps get fitted for a scler- al lens) and try to avoid the possibility of a transplant. Just by Ellen Stodola Editorial Co-Director D uring the "Keratoconus Essentials" symposium, presentations focused on a number of topics including diagnostic options, crosslinking, Intacs (Addition Technology), laser vision cor- rection, and considerations for cataract surgery. Kenneth Beckman, MD, Columbus, Ohio, presented on how to diagnose and recognize progression of keratoconus and ectasia. Making the diagnosis of keratoconus and ectasia is tricky, he said. It involves sev- eral different parameters, and "there's no one silver bullet to make the diagnosis." We like to start with a good history, he said, but while there are many classic, histor- ical findings that you see with keratoconus, they are very nonspecific. They could include things like rapidly changing vision (increasing myopia and refraction), the inability to fully correct with glasses, and more. Other non-visual things you might see are a history of atopic disease, Down syn- drome, sleep apnea and floppy eyelids, or itching eyes and tendency to rub eyes, he said. Clinical findings to look for include striae in the cornea, thinning of corneal slit beam, etc., he said. However, Dr. Beckman noted that some of the clinical findings may not occur until later so these alone may not be sufficient to proper- ly diagnose keratoconus. He moved on to discuss topography and tomography, highlighting some of the find- ings that might be seen: • Localized area of steepening • Irregular astigmatism • Asymmetric bowtie • Skewed bowtie/radial axis Making the diagnosis of keratoconus and ectasia is tricky. It involves several different parameters, and "there's no one silver bullet to make the diagnosis." —Kenneth Beckman, MD

• Cover