EyeWorld India March 2019 Issue

54 March 2019 EWAP REFRACTIVE The value of macular OCT for the refractive cataract patient by Michelle Stephenson EyeWorld Contributing Writer O ptical coherence tomography (OCT) has changed the management of many retinal diseases. Using this technology, physicians can quantify details of the retinal anatomy easily and accurately, which makes it an important tool for refractive cataract surgery evaluation. “I think macular OCT is truly useful for advanced cataract evaluation,” said John Hovanesian, MD, Harvard Eye Associates, Laguna Hills, California. Preeya Gupta, MD, associate professor of ophthalmology, Duke University School of Medicine, Durham, North Carolina, agreed. “In my clinic, if a patient has chosen premium lens technology, I will get a macular OCT. Additionally, I’ve recently incorporated using swept-source biometry with the IOLMaster 700 device [Carl Zeiss Meditec, Jena, Germany], which takes a 1-mm snapshot of the fovea. So you’re getting an image of the fovea while you’re acquiring biometry. If we see anything abnormal, the technicians do a full OCT,” Dr. Gupta said. Douglas Koch, MD, Allen, Mosbacher, and Law Chair in Ophthalmology, Baylor College of Medicine, Houston, said that he gets a macular OCT on every new patient and on every preoperative cataract patient. “For me, it is an invaluable part of the retinal examination. Neither I nor my patient want any surprises. As an integrated part of the preoperative evaluation, it is an essential part of my surgical planning and helps me provide my patients with reasonable postoperative expectations,” he explained. What can we learn? According to Dr. Hovanesian, in the setting of a visually significant cataract, the view of the macula is compromised for every patient, and non-obvious pathology can derail satisfaction with surgery if it’s not detected preoperatively. “The OCT helps us to diagnose what is sometimes undiagnosable by a normal exam. I don’t think it’s a substitute for looking at the macula, but it gives more detail than one can sometimes get by looking through a cataract. Some of the most commonly missed disease pathologies would be epiretinal membrane and vitreomacular traction. Another would be very subtle macular degeneration that might not be obvious when looking through a cataract. Occasionally, we’ll find someone with chronic cystoid macular edema or diabetic macular edema that we can’t see on exam. It is a question of how bad the cataract is and how subtle the macular disease is. But the OCT, at the very least, gives us confirmation of a healthy macula in the majority of patients,” he explained. Dr. Koch said that it rules out any macular issues, which might affect lens choice and could alter the postoperative visual prognosis or the postop recovery in some way. Dr. Hovanesian said significant macular disease will alter the decision for a premium implant. “If I see a significant epiretinal membrane, I’m not going to recommend a multifocal or other presbyopia-correcting lens, unless I think the visual potential is at least 20/25. I might recommend a toric lens, though, if there’s sufficient astigmatism to warrant it, because I think that we are promising less and we’re still benefiting the patient with the astigmatism correction. There’s not a lot of black and white here. In a macula that’s clearly abnormal, and the abnormality is evident without OCT, I would generally not offer any type of refractive cataract surgery,” he said. According to William Trattler, MD, Center for Excellence in Eye Care, Miami, whether or not to proceed with a presbyopia- correcting IOL in the presence of an abnormal macular OCT can be a difficult decision. “The surgeon needs to try to provide good, appropriate informed consent. However, the results of a presbyopic IOL can be quite variable in a patient with an abnormal macular OCT, including when there is an ERM, VMT, or other macular irregularity. Some patients with A preop image with a diagnosis of vitreomacular traction syndrome. 6 weeks postop, on difluprednate and bromfenac for the entire 6 weeks. Source: William Trattler, MD [OCT] gives me the assurance of having a better idea of what’s going on in the macula than I would otherwise. – John Hovanesian, MD