Expert clinicians often describe the evolution of their mastery as “experience.”23 Indeed, medical training spans a decade or more, from medical school to residency and fellowship. However, expanding medical education requirements have marginalized ophthalmology teaching, necessitating more efficient ways of delivering educational content.7 Moreover, it is becoming increasingly clear that clinician “experience” relates to crucial but somewhat neglected aspects of learning. In particular, perceptual learning, an implicit and gradual learning process, advances via many classification episodes rather than through explicit verbal or procedural instruction, and produces pattern recognition and intuitive knowledge that is often not verbalizable.6 This study demonstrates significant improvements in diagnostic accuracy, fluency, and confidence following a PALM for optic nerve disease pattern recognition that required, on average, eight minutes to complete. Learning was durable over time, despite the absence of further engagement with this material, and superior to an intervention modeled on a traditional lecture. This is the first study to validate the efficacy of a PALM in ophthalmology and the first in any medical specialty to compare the PALM to a more traditional, lecture-based learning intervention.
The rapid learning improvements observed in this study are consistent with those of PALMs in other medical specialties. A histopathology PALM for medical students requiring 11 to 17 minutes of engagement demonstrated large increases in accuracy and fluency sustained at six weeks, with more efficient learning observed among students familiar with the PALM format.23 Similarly robust learning followed dermatology PALMs for medical students and ECG PALMs for medical students and emergency medicine residents, with an even longer follow-up time of 12 months.22, 25 Improved diagnostic expertise following PALMs for TEE24 interpretation have also been shown among anesthesiology residents to be maintained over a six-month period, regardless of baseline proficiency. This study is unique in that, unlike the subject matter in previous PALMs, ophthalmology is not a core component of the medical curriculum. The optic nerve PALM resulted in substantial learning for medical students at all levels of training despite minimal to no prior exposure to such content. PALMs are likely applicable to a broad swathe of ophthalmic pathology, from retinal disease to cup-to-disc size estimation.
In contrast to the conventional “lecture and test” approach,28 perceptual and adaptive techniques offer learners a more active learning experience. Learners practice using real-world images and performance is measured throughout – rather than at the end of – the learning process to provide feedback in real-time.21 While trainees are generally able to follow and easily recognize patterns highlighted in a presentation, they classically encounter difficulty when a new image is encountered independently.23 Hence, the development of expertise requires a refined “information extraction system, not a storehouse of memorized instances.”29 This system, which follows different laws of learning from declarative memory, requires exposure to many relevant examples.23, 30 PALMs allow visualization of the variations in presentation of many diseases that learners would otherwise encounter gradually over months to years of training, likely explaining the large and reliable improvements in diagnostic automaticity observed in this study and others. Additionally, frequent testing coupled with feedback, integrated into the learning process, have been shown to promote stronger, more durable learning,31 even when the content is new and not previously studied.32
Delayed test scores declined substantially for both groups, with the PALM maintaining superiority by only a moderate margin, based on effect sizes, and the differences in both accuracy and fluency hovering very close to the 0.05 cut-off for statistical significance. As the majority of medical students in this study were not immersed in clinical ophthalmology, they likely lacked the continued exposure required to consolidate and retain the learning. Active re-learning and spaced repetition, particularly in expanding time intervals, have been shown to improve long-term retention.32, 33 The practical application of this PALM would be among medical students or residents prior to or during a clinical rotation, wherein continued exposure to ophthalmic pathology would be expected to improve long-term retention.
Many participants in this study – in both intervention groups – appreciated either form of exposure to ophthalmology. Indeed, medical students and general medical practitioners perceive their undergraduate training in ophthalmology to be inadequate and desire more teaching.34 The widespread marginalization of ophthalmology teaching has ramifications even for students pursuing non-ophthalmic specialization. Eye-related complaints comprise up to three percent of all primary care office visits,35 a proportion certainly to increase given the aging population,2 yet general medical practitioners lack confidence and minimum competency for managing ophthalmic problems.5 PALMs may offer an effective and efficient modality for such instruction. For the medical student and general provider population, we recommend combining the PALM with foundational content either via a supplemental lecture or, preferably, integration into the PALM.
There are a few limitations to review. This PALM is designed to require a minimum of three intervening trials before a particular diagnosis could be repeated. Since this study included five diagnostic categories, retired categories were incorporated to maintain the minimum spacing requirement as soon as one category had been retired. Thus, adaptive techniques were not fully applied and participants inevitably reviewed already mastered categories (although these were strictly “filler” and not included in any sequencing or mastery criteria). More robust learning and retention may have been observed in a PALM with additional categories. A direct comparison between the PALM and lecture was also limited by the shorter duration of the lecture relative to the PALM. However, a post-hoc analysis simulating a post-test occurring contemporaneously between the two groups suggests that most of the short-term learning occurred in the first few minutes of the PALM.