A single-center, prospective, randomized, controlled intervention trial to validate an inexpensive practice model for acquisition of microsurgical skills. Following a pre-assessment microsurgical skills task, participants were randomized to either an intervention group to build a micro-stellated icosahedron, or to a control group with no specific task assigned. A post-assessment microsurgical skills task was given to all participants after two weeks. Videos of pre- and post-assessments were masked and independently rated by two ophthalmologists using Video-based Modified Objective Structure Assessment of Technical Skill (OSATS) scoring criteria. Analyses were done to determine improvement in time required to complete tasks and in scores between pre- and post- assessments.

This study is a single-center, prospective, randomized trial approved by the University at Buffalo Institutional Review Board. Medical students, residents and other interested individuals without prior microsurgery experience affiliated with the Jacobs School of Medicine and Biomedical Sciences were invited to participate. Each participant completed written informed consent.

Participants first watched an instructional video made by the Principal Investigator on how to pass a 9-0 nylon suture needle, and how to perform a microsurgical tie for a linear incision in a silicon baking mat using the same materials as would be provided to them for the pre- and post-assessments (Video 1). After watching the video three consecutive times, participants were tasked to pass and tie a 9-0 nylon suture in the same manner as the video recording. Their attempt at performing the microsurgical task was video-recorded for a pre-assessment with a cellphone camera focusing on the microscope field ensuring a clear view of the surgical field and the participant's instrument manipulation. Each subject wore gloves during the assessment to ensure anonymity.

After completion of the video-recorded pre-assessment, participants were randomized by flip of a coin to either the intervention group to build a micro-stellated icosahedron, or to the non-intervention control group with no assigned task. All subjects in both groups were required to return in two weeks for a second in-person meeting. At the second meeting, they were presented with the same instructional video as in the first meeting on how to pass a needle and perform a microsurgical tie. After watching the video three consecutive times, their attempt at completing a microsurgical tie was video-recorded for a post-assessment, using similar instruments and set-up as those used two weeks prior. Subjects in the intervention group were asked to return borrowed materials and their completed micro-stellated icosahedrons.

After all subjects were recruited, and their corresponding microsurgical tasks were video-recorded for pre- and post-assessments, each of the videos was edited to mute all audio in order to ensure anonymity. Each of the videos was de-identified by naming it with a random number from 1 to 42 and saved in a file folder in random order. This file folder was sent separately to two ophthalmologists, masked to the identity of the subjects (intervention vs control) and time of recording (pre- or post-assessment).

The raters used the Video-based Modified Objective Structure Assessment of Technical Skill (OSATS) Scoring Criteria, which scores four criteria with scores from 1 to 5: Economy of Movement, Confidence of Movement, Respect for Materials, and Precision of Operative Technique.4 The raters assigned separate scores for the participant's attempt at passing the needle through the incision, and for their attempt at tying a microsurgical tie. The attempt at passing the needle (Pass: Total) had a maximum possible score of 20, and the attempt at tying a microsurgical tie (Tie: Total) had a maximum possible score of 20, making 40 the maximum possible total score for each video (Total: Pass+Tie). The time each subject took to pass the needle, and the time each subject took to attempt tying a microsurgical tie was measured in number of seconds.

Inclusion Criteria:

• 18 year-old or older.
• No prior microsurgical experience.

Exclusion Criteria:

• Prior microsurgical experience.

In order to judge the effectiveness of intervention, participants in the intervention and control groups will perform a microsuturing task at the beginning and at the end of the study to grade surgical skills. Before each grading session, subjects will watch video instructions on how to perform microsurgical suturing. The subjects' microsurgical manipulations will be video-recorded. The video-recordings will be rated by 2 ophthalmologists, including the main investigator, masked to the identity of the subject (intervention vs control) and time of recording (either before or after intervention). Videos were muted, and subjects were instructed to wear gloves in order to ensure anonymity.