EyeWorld India December 2017 Issue

Don’t write off manual toric marking just yet by Stefanie Petrou Binder, MD, EyeWorld Contributing Writer Freehand marking using ne tipped tissue marking pen Simulation of intraoperative view of reference markings Surgeons still prefer to back up digital, automated measurements with manual markings M anual toric mark- ing feels safer for many surgeons. Despite many new and sophisticated modalities to determine toric IOL placement and alignment, most clinicians will back up a reading with manual marking to ensure their toric IOL is properly placed, at least until automated systems are proven more reliable than the manual methods. Although manual marking systems are the current standard in guiding intra- operative toric IOL positioning, they do involve various sources of error, mostly associated with pa- tient head position or washing out of preoperative marks. Speaking at the 2017 ASCRS•ASOA Sympo- sium & Congress in the “Optimiz- ing Outcomes: What am I Doing Differently?” session, Samaresh Srivastava, DNB , Raghudeep Eye Hospital, Ahmedabad, India, discussed current modalities. Basic technique It is vital for all eye surgeons to have a solid understanding of ba- sic toric marking procedures, even if their practice uses an automated method. “Technology is some- times 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 centra- tion,” 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 reinforc- ing 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 freehand 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 to- ric marking. “The bubble marker, 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 bub- ble cage is on the arm of the de- vice, 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 refer- ence 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 bubble aligned when you are marking the cornea, making cor- rect head position crucial. Using the electronic device, the marker lights green when the device is properly aligned in the horizon- tal 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.” Freehand 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 manual markers but have shifted to freehand mark- ing on a slit lamp. The slit lamp gives a better positioning for the “ Automated systems are the way to go, since manual marking has some issues with patient comfort and IOL centration. In our clinic, we use both methods for the majority of our patients. ” - Samaresh Srivastava, DNB EWAP CATARACT/IOL December 2017 61 continued on page 62