Eyeworld

EW CATARACT 46 September 2017 by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer ual markers but have shifted to free- hand marking on a slit lamp. The slit lamp gives a better positioning for the patient. It keeps the head fix- ated using a forehead rest and a chin rest, keeping the patient's head in the right plane and position. Some slit lamps have their own gauges, so you can use the 90-degree and 180-degree references by rotating the slit lamp and marking these areas," Dr. Srivastava explained. toriCAM toriCAM, developed by Graham Barrett, MD, is one of the most pop- ular toric marking devices currently in use. The free app uses a guidance scope that allows for an easy, user- friendly implementation. toriCAM lets the surgeon determine the axis of corneal marks for the right toric IOL alignment intraoperatively and measures the implanted IOL axis at the slit lamp postoperatively. "We have shifted to the tori- CAM in our clinic," Dr. Srivastava said. "The guidance scope helps us in guidance and navigation auto- mated piloting by using gravity and allowing us to use free markings to our advantage. I can make markings on the horizontal 180-degree axis a very popular device, works on the principle of gravity, where the surgeon marks a patient's eye while keeping the air bubble steady," Dr. Srivastava. "The bubble cage is on the arm of the device, and it is important to always keep the bubble aligned at all points in time between the lines. Three prongs, one at 90 degrees and two at 180 degrees, give reference points. We used to give a distant fixation target with a flash light in our clinic, but now we use a non-accommodating target. It is not the easiest task to keep the bub- ble aligned when you are marking the cornea, making correct head position crucial. Using the electronic device, the marker lights green when the device is properly aligned in the horizontal plane and lights orange/ red if alignment is tilted outside of the horizontal plane. Essentially, we have the same problem as with the bubble marker because it is very hard to keep an eye on the patient's eye and the device while you are marking." Free-hand marking involves three marks, two at 180 degrees and one at 90 degrees, used as gauges for horizontal marking. "We used this method for a long time using man- Basic technique It is vital for all eye surgeons to have a solid understanding of basic toric marking procedures, even if their practice uses an automated method. "Technology is sometimes better in theory than it is in reality. Still, automated systems are the way to go, since manual marking has some issues with patient comfort and IOL centration," Dr. Srivastava said. "In our clinic, we use both methods for the majority of our patients. It is very important never to forget to mark the cornea." For toric marking, he recom- mended drying the temporal and nasal eye areas, as marking pens tend to bleed, marking the reference points, and reinforcing the marks again, once in the operating room. Corneal marking needs to be carried out in a seated position to avoid cyclotorsion (resulting from a supine position), which could easily distort the axis. When marking free-hand in the OR, the patient's chin should be in the right position, with no head tilt or face turn. Two manual markers, one electronic and the other a bubble marker, are commonly used for toric marking. "The bubble marker, Surgeons still prefer to back up digital, automated measurements with manual markings M anual toric marking feels safer for many surgeons. Despite many new and sophis- ticated modalities to determine toric IOL placement and alignment, most clinicians will back up a reading with manual marking to ensure their toric IOL is proper- ly placed, at least until automated systems are proven more reliable than the manual methods. Although manual marking systems are the current standard in guiding intraop- erative toric IOL positioning, they do involve various sources of error, mostly associated with patient head position or washing out of preopera- tive marks. Speaking at the 2017 ASCRS•ASOA Symposium & Con- gress in the "Optimizing Outcomes: What am I Doing Differently?" session, Samaresh Srivastava, DNB, Raghudeep Eye Hospital, Ahmedabad, India, discussed current modalities. Don't write off manual toric marking just yet Freehand marking using fine tipped tissue marking pen Simulation of intraoperative view of reference markings

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