Commentary: Assessing surgical competency of novice surgeons using a three-dimensional heads-up display microscope

The traditional surgical teaching of “see one, do one, teach one” does not translate to phacoemulsification, which is an extremely dynamic surgical procedure requiring excellent hand-eye coordination, fast reflexes, and an understanding of the different anatomical depths at various steps of the procedures. Various methods have been described to train resident doctors in phacoemulsification, including performing surgery on a goat’s eye in the wet lab, simulators to practice surgical skills, and supervised surgeries on actual patients.[1]

Three-dimensional heads-up display (3-D HUD) systems have emerged as an innovative teaching and training tool in ophthalmology, enabling novice surgeons to observe a magnified view of the operating field with enhanced depth perception, and facilitating their understanding of the surgical dynamics.[2,3,4,5]

The authors compared the competency scores of novice surgeons when performing phacoemulsification on a 3-D HUD system or traditional microscope and observed significantly higher surgical competency with the 3-D HUD system.[6] As per the authors, the improved surgical performance may be attributed to the enhanced stereopsis and spatial awareness while operating with the 3-D HUD system. A significant increase in surgical competency with successive cases was observed in the steps of rhexis completion, intraocular insertion of instruments, nucleus sculpting, irrigation-aspiration, and maintaining eye and instrument stability as well as centration. The magnification of the 3-D HUD system is useful for the completion of delicate maneuvers such as capsulorhexis. An improved stereopsis helps the trainee surgeons grasp the depth of the trench during sculpting. Enhanced spatial awareness facilitates ease of handling instruments and maintaining ocular stability.

The total surgical duration of the novice surgeons was significantly less for cases operated using the 3-D HUD system as compared with the traditional microscope. Novice surgeons experience difficulties in spatial awareness when looking through the oculars of the traditional operating microscope and often face challenges in handling surgical instruments. The increased peripheral visual field with the 3-D HUD system helps offset these challenges, which can explain the decreased surgical time. In contrast, experienced surgeons experience an increased surgical duration with the 3-D HUD system, which has been explained by the need to adjust the operating table and chair, and optimally align the line of sight to the display screen.[3]

Another aspect that deserves consideration is the ability to operate at significantly decreased illumination levels with a 3-D HUD system.[5] The mean surgical time in this study was approximately half an hour for the novice surgeons, and the low illumination helps enhance patient comfort and cooperation in prolonged surgeries performed by trainees.

The better ergonomics afforded by the 3-D HUD system and a lower incidence of back strain have been well-established.[3,5] However, persistently viewing the display screen at an angle does induce significant torsional neck strain. A temporal approach is preferred for most phacoemulsification surgeons, which necessitates the placement of the display screen at an angle to the surgeon to avoid obstruction by the microscope head. A slight head-turn to view the screen is inevitable and may result in long-term strain for the surgeon and should definitely be considered.[3,4]

The cost and widespread availability of the 3-D HUD system also deserve consideration as it may not be feasible for all teaching centers to acquire this technology. In addition, surgeons trained using the 3-D HUD system may find it challenging to shift to traditional operating microscopes, with a period of adjustment required with the different systems. The authors do not report any adaptation difficulties faced by the trainee surgeons with the 3-D HUD system.[6] This may be explained by the fact that the trainee surgeons had negligible prior surgical exposure, thereby finding both traditional microscopes and 3-D HUD equally difficult. An initial learning curve with 3-D HUD systems is well-documented in experienced surgeons trained on traditional operating microscopes.[2,3] The different magnification levels, illumination levels, surgeon position, and ergonomics of the two systems will always be associated with an adjustment period while switching between the two systems. Optimal display clarity with 3-D HUD systems is dependent on minimal external illumination in the operating room, which poses difficulties for the assisting surgical staff, especially while handling instruments and loading intraocular lenses.[3,4]

To conclude, teaching systems are continually evolving and increasingly involve the use of technology. The 3-D HUD system, in addition to being a state-of-the-art technology, is also an invaluable tool to train surgeons in various ophthalmic procedures. Phacoemulsification has a steep learning curve with an increased incidence of sight-threatening complications such as posterior capsular rent in the initial cases. The use of 3-D operating microscopes helps in faster skill acquisition and improves the surgical competency scores of trainee surgeons. Future developments may encompass the use of virtual reality simulator headsets, which may further decrease the learning curve of this dynamic surgery and improve patient safety.