Eyeworld

EW MEETING REPORTER 122 EyeWorld reports from the 2018 Combined Ophthalmic Symposium (COS), August 24–26, Austin, Texas She concluded with some of her pearls for astigmatism correction in complex cases, which included advising patients of inaccuracies/ limitations, using multiple measure- ments and looking for consistency, being aware of OSD, and being aware of premium IOLs. Editors' note: Drs. Donaldson and Raviv have financial interests with a number of ophthalmic companies. Pearls in cornea and refractive surgery Terry Kim, MD, Durham, North Carolina, presented on corneal ede- ma after cataract surgery, highlight- ing several causes: dense brunescent cataracts, Fuchs' endothelial dystro- phy, and retained lens fragments. Dense brunescent cataracts, Dr. Kim said, are very dense in nature, with a large endonucleus/minimal epinucleus and cortex. The posterior epinucleus becomes firm, adher- ent, and difficult to fracture due to bridging posterior lens fibers, and there is resistance of the posterior nucleus to full cleavage regardless of the phaco technique. Dr. Kim added that it is most apparent in the pos- terior aspect of the central nucleus, resulting in the inability to engage the apex of the nuclear fragment in the phaco tip. presbyopia astigmatism correcting IOLs. Pre-existing corneal conditions may include ocular surface disease, anterior basement membrane dys- trophy, or Salzmann's degeneration, Dr. Donaldson said, stressing the need to look at topography and Plac- ido images as well as tomography. Dr. Donaldson said that when dealing with keratoconus, you can use toric IOLs in some of these patients: those with mostly regular astigmatism, when there is signifi- cant improvement with refraction, if the patient is able to wear glasses with improvement some of the time, with stable Ks, and for patients with reasonable expectations. For those patients with a history of PK, Dr. Donaldson said you want to try to have all sutures removed before CE/IOL, want residual stable regular astigmatism, want a healthy graft, and want a reasonable patient. Some concerns for these patients are that the astigmatism may change with time, and astigmatism will change if the graft is repeated. Dr. Donaldson highlighted some features of a good toric candidate after prior corneal refractive surgery: primarily regular, stable, repeatable astigmatism, minimal OSD, old records, reasonable expectations, no signs of progression or corneal steep- ening over time, and no signs of unstable vision throughout the day. a trabecular meshwork (TM) stenting procedure may be appropriate. For moderate/severe glaucoma, he sug- gested TM ablations, suprachoroidal, or subconjunctival procedures. For a glaucoma practice, he suggested be- ing comfortable with all MIGS and traditional glaucoma procedures. Editors' note: Dr. Patrianakos has no financial interests related to his comments. Dr. Samuelson has financial interests with a number of ophthalmic companies. Premium cataract surgery Tal Raviv, MD, New York, shared his five steps to toric IOL success. He first stressed the importance of accounting for posterior corneal astigmatism and mentioned that using the Barrett toric calculator can help with this. There is less with-the- rule and more against-the-rule than anterior measurement indicates, so you should undertreat with-the-rule and overtreat against-the-rule. Next, Dr. Raviv recommended setting surgically induced astig- matism (SIA) to 0.1 D. Accuracy increases by using temporal corneal incision on all patients, he said, adding to use a centroid value of 0.1 D in toric calculators. Dr. Raviv's third step was to recognize long-term astigmatic drift. With-the-rule will drift to against- the-rule in all eyes at an average rate of 0.34 D per decade. He said that axis flipping can be a tool, and you should target the lowest cylinder while keeping long- term drift in mind. It's better to flip from against-the-rule to with-the- rule since it will drift back, he said. Dr. Raviv said refractive cylinder is a clue. In older patients, when the refractive cylinder against-the-rule is larger than the corneal cylinder, you have to treat that. During her presentation on astigmatism management in chal- lenging cases, Kendall Donaldson, MD, Plantation, Florida, highlighted what she considers the five most challenging cases of astigmatism management: pre-existing corneal conditions, keratoconus, history of penetrating keratoplasty (PK), histo- ry of corneal refractive surgery, and October 2018 continued on page 124 View videos from COS 2018: EWrePlay.org Leela Raju, MD, discusses logistics of including crosslinking in a clinical practice.

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