HRT scan may be easier for the patient than angiography MACULAR screening with the Heidelberg Retinal Tomographer (HRT) is an excellent way to screen patients and to follow the progression and resolution of cystoid macular oedema in post-cataract extraction patients, according to Jay Wallshein MD.
He conducted a study that evaluated the utility of the instrument in detecting cystoid macular oedema in 13 patients following cataract surgery. He performed an initial scan following the surgery and then repeated scans weekly to detect the development of cystoid macular oedema. He also performed dilated macula exams, weekly.Any patient who had a decrease in visual acuity or had a macular thickness of 2.0 (an arbitrary unit of measurement) or greater as determined by the HRT instrument went on to have a confirmatory intravenous fluorescein angiogram. Of the 13 patients in the study, 10 have maintained a visual acuity of 20/20 or better and had macular thickness of less than 2.0 on all scans. A decrease in visual acuity was found in three patients. In these patients, the retinal tomography detected a macular thickness greater than 2.0 and the intravenous fluorescein angiogram (IVFA) documented the presence of cystoid macular oedema (CME). As the vision of the treated patients improved, the researchers noted a corresponding decrease in macular thickness on HRT and decreased leakage on IVFA. In addition, when CME resolved after treatment, the macular thickness also decreased to less than 2.0. In an interview with EuroTimes, Dr. Wallshein emphasized the usefulness of macular Heidelberg Retinal Tomography in determining the thickness of the macula after a cataract surgery, especially when compared with earlier techniques: "Previously, you had to dilate the patient and had to have a fluorescein angiogram to confirm the disease, and subsequent angiograms to determine if the patient was improving or not. When your patients have a decrease in vision after surgery, you need to find out why. This requires dilation of the pupil and often a fluorescein angiogram as well, which is very time-consuming. The patient has an injection in the arm, has to sit around, the urine and skin can be orange for a day or more, they can have severe allergic reactions to the fluorescein, and it can be a very uncomfortable procedure." The HRT procedure frees the patient from the necessity of undergoing dilation every week or two and saves them the discomfort of the fluorescein angiogram, which can be very invasive. This machine can now be used to diagnose the condition and follow the resolution.
Dr Wallshein said that the use of the HRT machine makes the patient's life much easier after cataract surgery when complications may develop. And they do develop. Cystoid macular oedema after cataract surgery can occur in as many as 3%-5% of patients and can lead to a permanent decrease in visual acuity. Sub-clinical cases may increase the percentage further. With the help of the HRT procedure, it is more easily detected and treated. "Fluorescein angiography and frequent dilations only makes the patient more stressed and makes it more difficult for the patient in terms of the outcome," Dr. Wallshein said. He added that making it possible to avoid that difficult procedure makes the macular Heidelberg Retinal Tomographer a useful instrument, which is affordable in a busy ophthalmology practice. "It is actually a computer program that you need only to add to the instrument in order to diagnose this condition to treat it. When you are a high-volume cataract surgeon, you want to be able to diagnose conditions that may reduce your patient's vision. If you can do that very simply with a simple test, and follow it very simply, your patient will be much happier," Dr. Wallshein told EuroTimes. New York ophthalmologist Marcus Edelstein, MD, PhD, agrees about the beneficial nature of the HRT procedure, for physician and patient alike. "One always likes to have a more objective way of evaluating what's happening when you have cystoid macular oedema, not just asking the patient. And the alternative would be to have a fluorescein angiogram, which is more invasive and may have side effects and requires that the patient be dilated," he told EuroTimes. Fluorescein angiography is more expensive than doing the HRT, which is non-invasive, takes a minute and does not require an injection of the vein with a dye. Moreover, the outcome of both procedures appears to be equivalent, he pointed out. "I think eventually, as ophthalmologists become more familiar with it, they will start to realise the advantages of using an instrument like the HRT to deal with cystoid macular oedema, as well as some other possibly inflammatory diseases of the retina and choroid, which may require management with steroids or other medications. It is an objective way of trying to judge what is happening during the follow-up of CME," Dr. Edelstein added. Dr Wallshein presented his study at the annual meeting of the Association for Research in Vision and Ophthalmology. Jay Wallshein, MD | ||||||||||
