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EW CATARACT 19 by Ellen Stodola EyeWorld Staff Writer Preoperative macular OCT testing Macular testing may be useful prior to cataract surgery A lthough most surgeons do not usually order macular testing before a routine cataract surgery, preopera- tive OCT testing may help to detect macular or retinal disease that is present, and it could be bene- ficial to address this prior to cataract surgery. Chirag P. Shah, MD, retina specialist at Ophthalmic Consultants of Boston, discussed screening for macular pathology prior to cataract surgery, when to use it, and what to look for. When to perform it Dr. Shah said it is unnecessary to perform a macular OCT on every pa- tient before routine cataract surgery. "One can screen for macular pathol- ogy with biomicroscopy at the slit lamp," he said. "If there is suspicion for macular disease, then check an OCT." In regard to premium IOLs, some surgeons will always check the macular OCT. "Again, many of these OCTs might be unnecessary, but many patients paying out of pocket for a premium lens expect perfect vision postoperatively," he said. An OCT can help detect subtle macular pathology. Dr. Shah said that this could cause additional stress for the cataract surgeon, and in premium IOL patients, just as for routine cataract patients, he recommends "a thorough examination before order- ing tests that might be unnecessary." What to look for "I like to evaluate a macular OCT in- ternally to externally," Dr. Shah said. One important factor to look at is the vitreoretinal interface, especially noticing any vitreomacular traction or vitreomacular adhesion. This is important to look for "because replacement of a thick cataract with a sleek IOL allows the vitreous body to shift anteriorly, [and] cataract sur- gery can exacerbate vitreomacular traction and affect central vision postoperatively." This movement could also be a cause of postopera- tive retinal tears and detachments, he said. Next, Dr. Shah said to look at the foveal contour, noticing if it is smooth and whether or not there is an epiretinal membrane. He said a surgeon should also look to see if there are any attenuated layers or any signs of cystic intraretinal fluid when looking at the cellular layers of the retina. Dr. Shah said to follow the nor- mal retina into the abnormal retina to find the pathology, then look at the inner-segment/outer-segment band, also known as the ellipsoid layer. Surgeons should be looking for any areas of discontinuity. "It should look sharp, crisp, and straight—likewise for the underlying RPE layer." He added that it's impor- tant to look for any drusen, subreti- nal fluid, or pigment epithelial detachments. Finally, Dr. Shah said to look at the choroidal layer to see if it is atrophic or if there is a choroidal neovascular complex. Diagnoses "Most diagnoses will be picked up by the clinical examination and then confirmed on OCT testing," Dr. Shah said. "These include vitreo- macular traction, vitreomacular adhesion, epiretinal membrane, lamellar or full thickness macular hole, foveal schisis, macular edema, nerve fiber layer edema (from acute ischemia) or attenuation (from remote ischemia or optic neuropathy), attenuation of the cellular layers of the retina (from ischemia or optic neuropathy), hard exudation, irregularity of the pho- toreceptor or RPE layers (e.g., from AMD or infectious/inflammatory disease), subretinal fluid, pigment epithelial detachments, choroidal atrophy, and choroidal neovascular- ization." He added that the pupil does not need to be dilated to perform the OCT. Dense cataracts Dr. Shah said an OCT can be per- formed on cataracts of different severities. It can be performed through dense cataracts, but "the signal strength and subsequent image quality will be diminished." "Reading the OCT often requires manipulation of the brightness and contrast, which can be done with the viewing software," Dr. Shah said. For extremely dense cataracts when it is not possible to obtain an OCT, a B-scan ultrasonography may be used to rule out obvious structural abnormalities such as vitreous hemorrhage, retinal detachment, or mass. EW Editors' note: Dr. Shah has no financial interests related to this article. Contact information Shah: cpshah@eyeboston.com W e have all heard the quote "What you don't know won't hurt you." Unfortunately, this is not necessarily the case in ophthalmology. I performed cataract surgery and implanted a toric IOL in a healthy 50-year-old lawyer. His surgery was routine but the outcome was anything but. Instead of having a happy patient with excellent uncorrected distance vision, he developed a macular hole with central distortion. He did not have a macular hole before surgery but most likely had vit- reomacular traction that was undiagnosed on a simple slit lamp biomicroscopy exam. Had I performed a preoperative macular OCT, I may have seen the traction and could have counseled him about the possibility of developing a macular hole. This case exemplifies the benefit of macular imaging before surgery. In this article, Chirag Shah, MD, a retina specialist at Ophthalmic Consultants of Boston, discusses the pros and cons and describes what cataract surgeons should be looking for in a macular OCT. Bonnie An Henderson, MD, cataract editor The patient is an 80-year-old woman who was referred by another ophthalmologist for cataract surgery. She has a brunescent cataract OD and vision of count fingers. Her posterior exam is limited due to the dense mature cataract. OCT reveals a macular hole that was previously undiagnosed. Source: Bonnie An Henderson, MD April 2014 Cataract editor's corner of the world

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