Keywords
undergraduate medical education - ophthalmology - microsurgery - motivation - surgical
simulation
The national supply of surgeons is projected to fall short of demand in 2025 with
ophthalmology facing the greatest national-level physician shortage.[1] Furthermore, medical students have traditionally displayed low interest in ophthalmology
with only 2.5 to 3.1% of medical school graduates preferring ophthalmology from 2005
to 2015.[2] A study on medical students' perception of ophthalmology showed that insufficient
exposure was a predominant reason for not pursuing ophthalmology.[3]
Curricular time dedicated to ophthalmology in medical school has been declining; however,
this decline has slowed and perhaps plateaued since 2014.[4]
[5] A survey by the Association of University Professors of Ophthalmology (AUPO) Medical
Student Educators' Council found that ophthalmology teaching is largely incorporated
into preclinical coursework, most commonly through lectures, followed by skills training
and problem-based learning.[4] Though all AUPO affiliated programs offered an ophthalmology elective, only a small
percentage had a required elective.[4] Clinical electives may offer minimal to no hands-on experience with ophthalmic surgery.
The current number of ophthalmology hours and teaching methods during medical school
may be insufficient to stimulate interest in ophthalmology.
Exposing medical students to ophthalmology during their undergraduate medical education
is a crucial step to increasing student interest in ophthalmology and potentially
addressing the nation's pipeline of future surgeons. Increased exposure to operative
procedures, surgical staff, and surgical simulation laboratories can increase students'
procedural skills and desire for surgical careers.[6]
[7]
[8]
[9]
[10]
[11] Integration of a wet laboratory into elective ophthalmology blocks or other parts
of the medical school curriculum can result in positive evaluations by medical students,
including increased interest in ophthalmology.[12]
[13] While previous studies have investigated the effect of surgical exposure and simulation
laboratories on career interest in surgical fields, including ophthalmology, to our
knowledge, none have focused on assessing the effect of ophthalmic microsurgical simulation
laboratories on intrinsic motivation grounded in the Self-Determination Theory (SDT).
The SDT is a theory of human motivation postulating that three basic psychological
needs—competence, autonomy, and relatedness—have to be satisfied to grow or achieve
intrinsic motivation.[14]
The purpose of this study is to evaluate the impact of an ophthalmic microsurgery
laboratory on student intrinsic motivation and interest in ophthalmology, as well
as comfort with microsurgery. We hypothesize that single-event exposure to laboratory-based
ophthalmic microsurgery would increase medical students' intrinsic motivation, explicit
career interest in ophthalmology, and comfort with performing basic ophthalmic microsurgical
tasks.
Methods
This study was conducted in August 2020 at the University of California, San Francisco
(UCSF) School of Medicine and approved by the UCSF Institutional Review Board. First-
through third-year medical students were recruited on a first-come, first-serve basis
using e-mail and Facebook posts on UCSF School of Medicine class pages. Fourth-year
students were excluded as they had already chosen their subspecialty of interest.
Intervention Design
Participants attended a Zoom-based lecture facilitated by ophthalmology faculty as
an introduction to microsurgery. The 25-minute lecture covered basic eye anatomy,
ophthalmic microsurgical instruments, and corneal suturing. Prior to participating
in the wet laboratory on corneal suturing, participants also watched a 5-minute instructional
video on operating microscopes during which an ophthalmology faculty member and resident
explained the basic microscope components that how to set the pupillary distance,
focus and magnification, and appropriate use of the foot pedals.
Four microsurgery wet laboratory sessions were held. Each wet laboratory session accommodated
only five students at a time to observe the novel coronavirus disease (COVID-19) precautions
on social distancing. All students and instructors were required to pass a daily health
screen within 4 hours of entering the wet laboratory and to wear personal protective
equipment consisting of facemasks as per UCSF institutional policy. Ophthalmology
residents and attending physicians were present to instruct participants during the
workshop in a 5:3 student-to-educator ratio. During the 2-hour workshop, participants
completed four progressively complex tasks in the following order: (1) macrosurgical
suturing on a surgical sponge using a 5–0 prolene suture; (2) microscope setup, including
setting the pupillary distance, practicing with the foot pedal, and adjusting focus
and magnification; (3) three-dimensional (3D) task under the microscope (threading
a standard sewing needle); and (4) microsurgical suturing under the microscope using
9–0 nylon sutures on a synthetic surgical simulation eye, PS-016 (Phillips Studio,
Bristol, United Kingdom). The fourth task involved a linear corneal laceration in
the simulation eye on which students practiced corneal suturing with interrupted sutures
([Fig. 1A–D]). The corneal suturing task consisted of four subtasks: loading a needle, passing
a suture, tying a knot, and overall suturing under a microscope. Throughout the laboratory,
supervising surgeons provided feedback and guidance to support students in completing
these tasks.
Fig. 1 Images of the wet laboratory's four progressively complex tasks. (A) Macrosurgical suturing on a surgical sponge using a 5–0 prolene suture, (B) microscope setup, (C) three-dimensional task under the microscope (threading a standard sewing needle),
and (D) microsurgical suturing under the microscope using 9-0 nylon sutures on a synthetic
surgical simulation eye with a corneal laceration (Phillips Studio, Bristol, United
Kingdom).
Data Collection Tools
Participants completed pre- and posttest surveys to collect data on baseline demographics,
prior surgery-related activities, factors influencing specialty preference, comfort
with surgical skills, and self-reported interest and familiarity with ophthalmology.
Rating of factors influencing specialty preference, comfort with surgical skills,
and self-reported interest and familiarity with ophthalmology used a 5-point Likert's
scale where 1 = not at all important/interested, 2 = slightly important/interested,
3 = moderately important/interested, 4 = very important/interested, and 5 = extremely
important/interested.
We adapted the validated Intrinsic Motivation Inventory (IMI) for inclusion into the
posttest survey.[15]
[16] The survey consisted of five subscales (interest, perceived competence, pressure,
effort, and value) assessed through 20 question items. Participants answered each
item using a 7-point Likert's scale where 1 = strongly disagree, 2 = disagree; 3 = somewhat
disagree, 4 = neither agree nor disagree, 5 = somewhat agree, 6 = agree, and 7 = strongly
agree.
In accordance with The American College of Surgeons, we defined surgery-related activities
as those in one of the following 14 surgical specialties: (1) cardiothoracic surgery,
(2) colon and rectal surgery, (3) general surgery, (4) gynecology and obstetrics,
(5) gynecologic oncology, (6) neurological surgery, (7) ophthalmic surgery, (8) oral
and maxillofacial surgery, (9) orthopaedic surgery, (10) otorhinolaryngology, (11)
pediatric surgery, (12) plastic and maxillofacial surgery, (13) urology, and (14)
vascular surgery.
Outcomes
The primary outcomes were the posttest IMI Composite and Interest subscale scores
and predictive regression analyses of the IMI Interest subscale score as the outcome
variable. Secondary outcomes included the differences between pre- and post-test Likert's
scores for specialty preference factors, self-reported familiarity and interest in
ophthalmology, and comfort with basic microsurgical tasks (loading a needle, passing
a suture, knot tying, and suturing under a microscope).
Statistical Analyses
We performed data analysis using Stata Statistical Software: Release 14 (College Station,
TX: StataCorp LP). We calculated the mean Likert's score for primary and secondary
outcomes. Pre- and posttest effect sizes were assessed for significance with the paired
Student's t-test (p < 0.05 was considered statistically significant) and nonparametric Mann–Whitney U-tests or Fischer's exact tests (for low incidences).
Predictive statistical analysis involved several simple linear regression analyses
of the IMI Interest subscale score or the Composite IMI score as the outcome variable
with all pre- and posttest measures as predictors. Furthermore, stepwise estimation
was performed to select a multiple linear regression model using forward and backward
stepwise selection of statistically significant predictor variables. This iterative
process starts with a model of the IMI Interest subscale score as the outcome variable
and all predictor variables check the significance of each predictor variable and
add or remove one predictor variable with the least significance each time, until
all the remaining variables are statistically significant (p < 0.0750).
Results
Twenty medical students at the UCSF were selected on a first-come, first-serve basis
in August 2020. Eighteen participants completed the pre- and posttest surveys (response
rate, 90%); two participants were excluded because of incomplete posttest surveys.
The study population consisted of 1 first-year student, 10 second-year students, 4
third-year students, and 3 students in the MD-PhD program.
Prior Exposure/Experience in Ophthalmology
[Fig. 2] shows participants' prior nonophthalmology surgery-related activities (i.e., other
surgical subspecialties) and ophthalmology-related activities. Of the participants,
15 (83%) reported having participated in at least one nonophthalmology surgery-related
activity with clinical shadowing as the most frequently reported experience (n = 12, 67% of students). Eleven participants (61%) reported having participated in
at least one ophthalmology-related activity, with didactics and clinical shadowing
being the most frequently reported activities (n = 9, 50% of students for both).
Fig. 2 Distribution of prior surgery-related activities in ophthalmology and other surgical
subspecialties. We defined surgery-related activities as activities in one of the
following 13 surgical specialties, excluding ophthalmology: cardiothoracic surgery,
colon and rectal surgery, general surgery, gynecology and obstetrics, gynecologic
oncology, neurological surgery, oral and maxillofacial surgery, orthopaedic surgery,
otorhinolaryngology, pediatric surgery, plastic and maxillofacial surgery, urology,
and vascular surgery.
Specialty Preference
At baseline, 14 participants (78%) reported a surgical specialty as their highest
ranked career preference with the following specialties cited most frequently (count,
percentage of the 14 responses): ophthalmology (n = 6, 43%); neurosurgery (n = 3, 21%); and general surgery (n = 2, 14%).
Participants also reported the influence of procedural skills, intellectual challenge,
and patient relationships on their specialty preference. On both pre- and posttest
surveys, 78% of participants reported that procedural skills were “very to extremely
important” in influencing specialty preference, while 17% of participants reported
that procedural skills were “not at all important.” Mean Likert's scores for the influence
of procedural skill were identical between pre- and posttest surveys (mean = 4; 95%
confidence interval [CI]: 3.46–4.54; p = 1.000. Mann–Whitney test showed no statistically significant difference between
pre- and posttest responses in the underlying distributions of Likert's scores for
procedural skills as an influence on specialty preference (p = 1.000).
All participants reported that intellectual challenge was “moderately important” to
“extremely important” in specialty preference. There was no statistically significant
difference in mean Likert's scores for intellectual challenge between pre- and posttests
(p = 1.000) or the distribution of Likert's scores (p = 0.958). Seventy-eight percent of participants reported that patient relationships
were “very important” or “extremely important” in specialty choice on both pre- and
posttest surveys. There was no statistically significant difference between pre- and
posttest mean Likert's scores for patient relationship (p = 0.680) or the distribution of Likert's scores (p = 0.888).
Familiarity and Interest in Ophthalmology
Between pre- and posttest surveys, the percentage of participants reporting to be
“not at all familiar” to “slightly familiar” with ophthalmology as a career declined
from 61 to 12%, while the percentage of “moderately familiar” to “extremely familiar”
increased from 38 to 55% ([Fig. 3A]). However, there were no statistically significant differences in mean Likert's
scores (p = 0.131) or the distribution of responses (p = 0.153). Similarly, students reporting to be “moderately interested” to “extremely
interested” in ophthalmology increased from 44 to 61%, without statistical significance
(p = 0.689; [Fig. 3B]).
Fig. 3 (A) How familiar are you with ophthalmology as a career? (B) How interested are you in ophthalmology as a career?
Comfort with Ophthalmic Microsurgery Surgical Skills
Comfort with ophthalmic surgical skills significantly increased between pre- and posttest
surveys for all five skills based on mean Likert's scores with the greatest increase
observed in comfort with passing a suture, 1.72 (1.04–2.49; p < 0.001; [Table 1]).
Table 1
Pre- and posttest mean Likert's scores for comfort with microsurgical skills
|
Microsurgical skill
|
Pretest mean Likert's score (SD)
|
Posttest mean Likert's score (SD)
|
Effect size (95% CI)
|
p-Value
|
|
Loading a needle
|
1.83 (0.85)
|
3.50 (0.98)
|
1.66 (1.04–2.20)
|
<0.001
|
|
Passing a suture
|
1.55 (0.85)
|
3.27 (1.12)
|
1.72 (1.04–2.40)
|
<0.001
|
|
Knot tying
|
1.94 (0.80)
|
3.00 (1.23)
|
1.05 (0.34–1.76)
|
0.005
|
|
Using a microscope
|
2.61 (1.28)
|
3.44 (1.04)
|
0.83 (0.04–1.62)
|
0.040
|
|
Suturing under a microscope
|
1.50 (0.85)
|
2.94 (0.80)
|
1.44 (0.88–2.00)
|
<0.001
|
Abbreviations: CI, confidence interval; SD, standard deviation.
Intrinsic Motivation Inventory Scores
We used the IMI scores to determine whether the microsurgical training influenced
students' intrinsic motivation. The Interest subscale, which is considered the self-reported
measure of intrinsic motivation, demonstrated the largest mean (standard deviation)
score of 19.44 (1.88), reaching 93% of the maximum possible score ([Table 2]).
Table 2
Posttest intrinsic motivation scores
|
Intrinsic motivation inventory subscales
|
Mean (SD)
|
Minimum
|
Maximum
|
Highest possible score
|
Percentage of highest possible score (%)
|
|
Interest score
|
19.44 (1.88)
|
16
|
21
|
21
|
92.57
|
|
Effort score
|
11.66 (1.94)
|
7
|
14
|
14
|
83.28
|
|
Pressure score
|
10.61 (3.82)
|
3
|
18
|
21
|
50.52
|
|
Value score
|
18.22 (2.75)
|
13
|
21
|
21
|
86.76
|
|
Competence score
|
18.50 (5.18)
|
8
|
27
|
28
|
66.07
|
|
Composite score
|
78.44 (8.15)
|
66
|
89
|
105
|
74.70
|
Abbreviation: SD, standard deviation.
Predictive Regression Analyses
To explore the relationship between IMI Composite scores with predictor variables,
we performed simple and multiple linear regressions which demonstrated that composite
IMI scores increased with improved posttest Likert's scores of comfort with loading
a needle (B = 2.86 [CI: 0.39–5.32]; p = 0.026) and explicit interest in ophthalmology (2.78 [−0.46 to 6.03]; p = 0.088). Forward and backward stepwise regressions generated similar findings.
Given that the IMI Interest subscale is the most direct measure of intrinsic motivation,
we also explored its relationship with predictor variables. Our analyses revealed
that the Interest IMI subscale increased significantly with five independent factors
([Table 3]; p = 0.005). Approximately 82% of the variability in Interest subscale scores was accounted
for by the variables in the model.
Table 3
Results of stepwise linear regression analyses with IMI interest subscale score as
the outcome variable
|
Predictor variable
|
B (95% CI)[b]
|
p-Value[a]
|
|
Comfort with using microscope, posttest
|
1.17 (0.40–1.9)
|
0.005
|
|
Knot tying skills, pretest
|
1.76 (0.26–3.2)
|
0.026
|
|
Familiarity with ophthalmology, posttest
|
2.36 (1.10–3.6)
|
0.002
|
|
Comfort with performing surgical maneuvers under a microscope, pretest
|
1.25 (0.13–2.4)
|
0.032
|
|
Interest in ophthalmology, pretest
|
0.97 (0.04–1.90)
|
0.042
|
Abbreviations: CI, confidence interval; IMI, Intrinsic Motivation Inventory.
a
p-Values show the significance of the predictive value of each independent variable
on the different outcome variables.
b B values are unstandardized regression coefficients that indicate the amount of change
one could expect in IMI interest score given a one-unit change in the value of that
variable all other variables in the model are held constant.
Discussion
Previous studies have investigated the effect of surgical exposure and simulation
laboratories on career interest in surgical fields, including ophthalmology, though,
to our knowledge, none have assessed the effect of ophthalmic microsurgical simulation
laboratories on intrinsic motivation. In our study, we administered the IMI tool,
which is validated for assessing participants' subjective experience of an intervention,
and which has been used in studies on intrinsic motivation across disciplines, including
clinical education.[17]
[18]
Our study demonstrated that a single ophthalmic microsurgery laboratory may increase
students' intrinsic motivation, comfort with microsurgical tasks, and explicit familiarity
with and interest in ophthalmology. Using the IMI scores as dependent measures for
the purpose of prediction, we observe that students with high scores for comfort with
microscopes, familiarity with ophthalmology, comfort with loading a needle, and explicit
interest in ophthalmology are more likely to report higher intrinsic motivation. Out
of the five measured subscales, the Interest subscale had the largest absolute value
and percentage of maximum value, while the pressure subscale displayed the lowest
absolute value and percentage. The Interest subscale assesses interest and inherent
pleasure when performing a specific activity and is the most direct measure of intrinsic
motivation.[19] The value subscale refers to internalization in which the person identifies with
the value of an experience and develops self-regulatory activities. The Effort subscale
assesses the individual's investment of their capacities into the activity.[19]
[20] Finally, studies have shown pressure to be a negative predictor of intrinsic motivation.[19]
[21] Thus, a significantly high Interest subscale would result if the positive predictors
are high and the negative predictors are low which is observed in our study.
Furthermore, perceived competence is theorized to be a positive predictor of intrinsic
motivation. Our participants' perceived competence scores averaged to 66% of the maximum
scores, which correlates with their increasing, yet moderate level of comfort with
several subtasks of the intervention. Studies have shown that increased perceived
competence and interest within an autonomous supportive learning climate predicted
specialty choice.[22] Our study participants reported high absolute values and percentage of maximum value
for Interest and Value subscales, suggesting that their likelihood of pursuing ophthalmology-related
activities may have increased; however, future monitoring is needed to validate this
prediction.
Our predictive statistical analyses show that both multiple and linear regression
models were significant, indicating that the overall models were significant. The
variability in Interest subscale scores was mostly accounted for by the predictor
variables. This suggests that increasing posttest comfort with microscopes and familiarity
with ophthalmology and increasing pretest comfort with surgical maneuvers under a
microscope, knot tying skills, and interest in ophthalmology could augment intrinsic
motivation. Comfort with microscopes may be an important factor of intrinsic motivation
for ophthalmology. The ability to integrate detailed visual information with fine
manual dexterity using stereovision under a microscope is critical to ophthalmic microsurgery.
Thus, it is plausible that increased comfort with the microscope positively predicts
interest in ophthalmology. Studies show that stereoscopic depth perception is advantageous
when initially learning to perform surgical skills under an operating microscope and
that poor hand–eye coordination was the most common problem for ophthalmology residents
failing to develop sufficient quality surgical skills.[23]
[24] As such, early exposure to the microsurgery laboratory may allow students to determine
if they are a good fit for subspecialties like ophthalmology.
The implications of this 120-minute laboratory are considerable, suggesting that single-event
activities can bolster student interest, comfort, and intrinsic motivation. The application
of SDT and intrinsic motivation to medical education has generated evidence across
numerous domains to guide curriculum design and elucidate learning processes in clinical
education settings.[18]
[25] Intrinsic motivation is an important aspect to consider when designing medical student
experiences, particularly for ophthalmology exposure, because it is associated with
increased deep learning, perseverance, well-being, specialty interest, and likelihood
of specialty selection.[14]
[22]
[26]
[27]
[28]
[29]
[30]
[31] Studies have shown that single-event surgery laboratories for medical students can
increase interest in surgery alongside competence in surgical-suturing techniques
and advanced surgical procedures.[6]
[8] Several single-event ophthalmology laboratories may be logistically easier to implement
than clinical electives which afford opportunities to counteract the national trend
of ophthalmology education shifting to preclinical years[5] by offering longitudinal integrated clinical years. Studies on microsurgical training
for medical students have shown that several regularly interspersed training sessions
can improve skill acquisition.[32]
[33]
Strengths and Limitations
Strengths of our study included a high response rate, anonymous surveys, robust statistical
analysis, and a well-crafted wet-laboratory course. There are several limitations
to this study. Our sample size was limited by COVID-19 public health precautions,
number of operating microscopes, short intervention duration, and desired learner-to-educator
ratio. A selection bias may have arisen as students who volunteered to participate
may have baseline characteristics that distinguish them from nonparticipants such
as greater interest in ophthalmology or other surgical subspecialties, motivation
by relationships with the research team, prior ophthalmology experience, or in need
of suturing skills practice to prepare for surgery rotations. Selection bias relating
to the recruitment process may have also occurred as we recruited participants via
e-mail and Facebook posts which is biased against individuals with limited access
to Facebook, e-mail, or the internet. Random selection of participants and a multimodal
recruitment process could have mitigated the distortion of our study's effect size
and confidence intervals. This would also help increase our sample size and medical
student participation.
Regarding the surveys, the pretest survey did not include detailed questions on the
exact frequency, length, type, or extent of involvement in surgical experiences which
may have impacted participants' comfort. Additionally, the study's primary outcomes
exclusively involved subjective measures. Inclusion of objective measures in future
studies to determine the effects of ophthalmic microsurgical training on skill building
is warranted. Furthermore, nonuse of procedural skills risks decay; hence, it is important
to consider more prolonged and frequent microsurgical simulation experiences. Heterogeneity
in teaching styles among resident and attending ophthalmologists could have impacted
the social context in which each participant completed the training, thereby affecting
each student's subjective self-assessment. Lastly, this study did not afford long-term
follow-up to determine the effect on students' pursuit of ophthalmology experiences
and residency selection. Further studies with larger sample sizes and multisession
interventions should be conducted using randomization and the development of objective
measures to assess the effectiveness of ophthalmic wet laboratories on intrinsic motivation,
microsurgical skills, and pursuit of ophthalmology, including monitoring of residency
selection outcomes.
Conclusion
Ophthalmic microsurgery laboratories for medical students can result in high intrinsic
motivation, increased explicit interest in ophthalmology, and comfort with basic ophthalmic
surgical tasks.
Incorporating ophthalmic microsurgery wet laboratories, with an emphasis on basic
microscope competence into preclinical ophthalmologic teaching, longitudinal electives,
or extracurricular opportunities could increase engagement, understanding, and interest
in ophthalmology as a career.
