Foldscope Versions: Educational Benefits and Limitations

Dear Editor, Inspired by studies assessing the foldscope (FS) in comparison with conventional optical microscopes for disease diagnosis, we highlight research such as Sivasankari et al.,[1] which investigates the efficacy of this tool in early oral cancer detection, and Gupta et al.,[2] which explores its use in the national malaria control program, both published in this journal. Recently, in the study by Gouveia et al.,[3] we evaluated the effectiveness of the FS versus the optical microscope in analyzing tissues from the thyroid, testicle, muscle tissues, tendons, and nervous tissue, assessing its feasibility as a teaching resource in basic histology for health science students. Histology plays a critical role in health sciences education, serving as a bridge between foundational biological knowledge and clinical application. By enabling the identification of normal and pathological tissue structures, it fosters essential diagnostic competencies in students. However, practical histology education often faces challenges related to accessibility, particularly in resource-limited settings. Tools like the FS address this gap by providing an affordable and portable solution for hands-on learning. During our previous article’s submission, peer review, and editing process, the company responsible for FS announced a new version of the device, FS 2.0, equipped with lenses capable of magnifying up to 360 times. This sparked our interest in exploring the applicability of this new version in the same educational context. Thus, this letter is a direct continuation of our previous research, now focusing on the potential improvements provided by FS 2.0. To conduct the comparative tissue study between the two versions of the FS, we used a prepared slide kit, model TIL-H-80, marketed by Opton Anatomic® (São Paulo, SP, Brazil). For image capture from both versions of the FS, an iPhone 14 Plus smartphone (Apple Inc., Cupertino, CA, USA) equipped with a 12MP wide-angle camera was utilized. The slide analysis was performed by two members of the core team of human body biosystems (basic health science educators) at our institution, both of whom have over 10 years of experience in teaching histology. The decision to involve two professionals was made specifically to avoid biases in interpreting the results, emphasizing only the aspects of agreement between the two analyses in this study. Comparing the two versions of the FS, we noted that FS 2.0 allows a clear distinction between parafollicular and follicular cells in the thyroid, a notable advance over the previous version. In the testicle, the visualization of spermatogonia has become possible, in addition to the seminiferous tubules already observable with FS 1.0. In muscle tissues, both skeletal and smooth, the morphology of the cells and the distribution of nuclei are now clearly visible, facilitating detailed histological studies [Figure 1].Figure 1: Comparison of visualization capabilities between Foldscope 1.0 viewed under 140× and Foldscope 2.0 viewed under 360×, across different tissues. (A) Thyroid gland stained with hematoxylin and eosin (H&E). (B) Longitudinal section of skeletal muscle in toluidine blue. (C) Testicle in toluidine blue. (D) Longitudinal section of smooth muscle stained with H&E. (E) Motor neurons stained with toluidine blue. (F) Longitudinal section of a tendon in H&EHowever, for muscle tendons and neurons, despite the greater magnification provided by FS 2.0, we did not identify significant differences in the ability to discern specific structures compared with the previous version. This indicates that the improvements are tissue-specific. It is also important to note that while the FS 1.0 was extremely affordable, the FS 2.0 is offered substantially higher. This price increase may affect the accessibility and dissemination of this tool in education and research, especially in resource-limited countries. The findings of this study emphasize the potential of FS 2.0 to enhance the quality of histological education for specific tissues. These improvements align with observations made by Hernández-Pérez and Nieto-Sobrino[4] highlighted that the FS is an effective and motivational tool in educational contexts, particularly due to its portability and simplicity in promoting active learning. Nevertheless, cost considerations must be balanced to maintain the broad applicability of this tool. In previous studies, our group evaluated the body projection technique, projecting anatomical images directly onto the human body to facilitate the teaching of anatomy. This approach proved to be an accessible and effective tool for anatomy education.[5] Subsequently, we refined this technique for teaching human physiology by incorporating physiological animations projected onto the body of a model, enabling a deeper understanding of the cardiovascular and cardiorespiratory systems.[6] These enhancements preserved the technique’s accessibility, making it a valuable tool for health education. In contrast, FS 2.0 sacrifices part of its original affordability, limiting its potential as a universally accessible educational resource. In conclusion, the FS 2.0 represents a significant advancement over its predecessor, offering improvements that may be crucial for certain histological applications. However, cost-benefit considerations are necessary to ensure its practical utility and accessibility. Author contributions Each author listed has engaged substantively in the study, fulfilling roles that merit authorship. Their contributions encompass conceptualization, methodology, data acquisition and analysis, and/or manuscript preparation. All authors have critically reviewed and approved the final manuscript, ensuring its integrity and scholarly merit. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.