Eyeworld

Dr. Matossian's protocol for every cataract surgery candidate •SPEED questionnaire, tear osmolarity, MMP-9, and meibography •Customized treatment plan, based on the ASCRS Preoperative Ocular Surface Disease Algorithm 4 •Comparison of measurements from various devices •If discrepancies are found between devices (more than 10 degrees difference in axis or more than 0.5 D in difference in magnitude of astigmatism), tear film must be reassessed and treated unless further improvement is not a realistic expectation. NOVEMBER 2019 | SUPPLEMENT TO EYEWORLD | 7 Cynthia Matossian, MD Impact of ocular surface disease on astigmatic outcomes and toric intraocular lens selection An optimized tear film provides the foundation for accurate measurements S urgeons are less likely to achieve the visual out- comes patients expect from toric IOLs if a patient's tear film is unstable. The tear film provides two-thirds of the refractive power of the eye. It must be stabilized to obtain reliable and consistent preopera- tive measurements that are plugged into appropriate for- mulas, said Cynthia Matossian, MD. "Relying exclusively on newer formulas is not going to yield the refractive outcome a surgeon wants without hav- ing reliable data to input into the formula," she said. Tear film impact Epitropoulos et al. reported that keratometry readings in one in five hyperosmolar eyes varied by at least 1 D between two consecutive preoperative visits. 1 "If the Ks are unsta- ble, the calculated power of the implant is going to be off because the K readings are a critical component in IOL power calculation," Dr. Matossian said. In a small pilot study, Dr. Matossian showed that ther- mal pulsation treatment for meibomian gland dysfunction significantly changed measure- ments of delta K and axis of astigmatism. 2 In 40% of eyes, either the IOL power and/ or the plan for astigmatism management changed after thermal pulsation. Diagnosing and managing ocular surface disease Many patients with ocu- lar surface disease may be asymptomatic. The PHACO study by Trattler et al. showed that 77% of cataract sur- gery candidates had corneal staining; however, 63% of patients never had symptoms of dryness. 3 Conclusion To obtain optimal results from toric IOLs in patients with ocular surface disease, Dr. Matossian optimizes the ocular surface and stabiliz- es the tear film as much as possible before performing preoperative measurements. She also recommends looking for reliability and consisten- cy between several devices before performing toric IOL calculations. n References 1. Epitropoulos AT, et al. Effect of tear osmolarity on repeatability of keratom- etry for cataract surgery planning. J Cataract Refract Surg. 2015;41:1672– 1677. 2. Matossian C, et al. Effect of thermal pulsation system treatment on keratometry measurements prior to cataract surgery. ASCRS ASOA Annual Meeting, 2019. 3. Trattler WB, et al. The Prospective Health Assessment of Cataract Pa- tients' Ocular Surface (PHACO) study: the effect of dry eye. Clin Ophthalmol. 2017;11:1423–1430. 4. Starr CE, et al. An algorithm for the preoperative diagnosis and treatment of ocular surface disorders: A report by the ASCRS Cornea Clinical Commit- tee. J Cataract Refract Surg. 2019; 45:669–684. Dr. Matossian is medical director and founder of Matossian Eye As- sociates in Doylestown, Pennsylva- nia, and in Hopewell, New Jersey. She can be reached at cmatossian@ matossianeye.com. Dr. Al-Mohtaseb is assistant professor of ophthalmology and associate residency program director, Cornea, Cataract, and Refrac- tive Surgery, Baylor College of Medicine in Houston. She can be reached at zaina@bcm.edu or 713- 798-5143. Dr. Chang is in private practice with Empire Eye and Laser Center in Bakersfield, California. He can be reached at dchang@empireeyean- dlaser.com or 661-325-3937. continued from page 6

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