Eyeworld

EW NEWS & OPINION 18 T he first attempt to measure surgeon fatigue in intraocu- lar surgery has been com- pleted, with results suggesting that ophthal- mologists should be able to com- plete the tasks without their performance deteriorating due to weariness. The study was published online in October 2010 in Graefe's Archive for Clinical and Experimental Ophthalmology. "It did not demonstrate a delete- rious effect of fatigue on surgeon performance after a regular operat- ing list in the National Health Serv- ice (NHS)," reported lead study author Salman Waqar, M.B.B.S., de- partment of ophthalmology, Torbay General Hospital, Torquay, England. In fact, a slight improvement was found among surgeons, likely due to repeated practice on the sim- ulator employed in the study, Dr. Waqar noted. Since this is reportedly the first study on IOL surgery-related fatigue, the technique used and data col- lected may be useful in understand- ing the true impact of exhaustion on surgeons; this will be understood better with more research. An approach to understanding fatigue Dr. Waqar recruited seven experi- enced ophthalmic surgeons, mean- ing they had completed more than 350 phacoemulsifications and IOL insertions, the minimum number of procedures required to complete training in the Royal College of Ophthalmologists. The surgeons received an orien- tation about the virtual reality cataract surgery simulator Eyesi (VR- magic, Mannheim, Germany). "Originally designed as a vitreo- retinal surgical training device, it now has a dedicated anterior seg- ment training module," Dr. Waqar reported. "It allows repeated meas- urements of standardized surgical tasks. Feedback is provided in the following main categories: surgeon efficiency, achievement of surgical target or goal, surgeon error/tissue injury, and formative education/ feedback. The forceps training mod- ule has previously demonstrated construct validity and we sought to use this to assess the effect of fatigue on intraocular surgical perform- ance." The device consists of a man- nequin head prop with a mechanical eye that pivots and rotates. "Various probes inserted into the mechanical eye can virtually emulate different intraocular instruments," Dr. Waqar noted. "A virtual operating micro- scope complete with zoom/pan/ focus foot pedal provides stereo- scopic images of the eye and instru- ments to the surgeon. A separate phacoemulsification foot pedal can also be used." Modules involving capsu- lorhexis or phacoemulsification can be loaded, and difficulty levels can be adjusted. "The Eyesi anterior segment for- ceps module requires the surgeon to grasp six objects from the periphery and place them in a net in the cen- ter," Dr. Waqar noted. "The module teaches surgeons to accurately grasp the edge of a capsulorhexis flap while keeping the eye centered and avoiding injury to the lens or cornea. For each attempt, the total possible score can range from 0 to 100. The simulator awards positive points for the percentage of the task completed and subtracts from this for reduced efficiency and errors." Surgeons completed 10 attempts on level four forceps module. Total score, total time score, corneal in- jury score, lens injury score, odome- ter score, and operating without red reflex score were recorded. The surgeons returned after their scheduled theatre lists to com- plete 10 more attempts on the same module. After the scheduled theatre lists, simulator parameters improved slightly, with total scores improving from 97.28 to 98.57 and total time improving from 44 seconds to 35 seconds. Both of these parameter improvements were statistically sig- nificant. "No detrimental effect of fatigue was demonstrated following a rou- tine operating list," Dr. Waqar con- cluded. "A slight improvement in performance was noted in the ma- jority of the measured parameters. We feel this represents a peak on the traditionally described 'S-shaped' performance curve indicating in- creasing surgeon capability with re- peated performance of a surgical task." Simulators are increasingly being used to analyze fatigue in vari- ous professional fields. "Virtual real- ity (VR) simulators have been used extensively in the airline industry to objectively assess the effect of fa- tigue on pilot performance," Dr. Waqar noted. "The assessment of fa- tigue using laparoscopic surgery VR simulators has also been reported." Dr. Waqar believes this simula- tor research method could be used to study fatigue in high-volume lists as well. "Future application could in- clude measurement of the 'fatigue- threshold' of each individual surgeon allowing the list to be ad- justed to their capacity," Dr. Waqar reported. Francis S. Mah, M.D., co-med- ical director, Charles T. Campbell Ophthalmic Microbiology Labora- tory, University of Pittsburgh School of Medicine, meanwhile, suggested that fatigue can indeed have an im- pact on surgery. "What I consider fatigue would be a surgeon up all night doing sur- gery, such as open globe, who doesn't get any sleep and has 40 cases the next day," Dr. Mah said. "In that scenario, you can imagine the last 10 results wouldn't be the same as the first 10." In this study, he said, "probably experience and muscle memory tend to make [the later cases] look a little better." Personally, Dr. Mah said, he feels fatigued more easily if he oper- ates on an empty stomach. Eating crackers in those circumstances, just to get some more carbohydrate in- take, helps, he said. "But it's some- thing you have to individually figure out," he said. EW Editors' note: Dr. Waqar has no finan- cial interests related to this study. Dr. Mah has no financial interests related to his comments. Contact information Mah: 412-647-2211, mahfs@upmc.edu Waqar: salmanwqr@gmail.com March 2011 by Matt Young EyeWorld Contributing Editor Physician fatigue may not have a "deleterious effect" on surgery

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