The Use of Prisms in the Management of Nystagmus: A Case Series and Literature Review

Purpose: The purpose of this study was to perform a retrospective case review of all nystagmus cases where subjective prism treatment was attempted in the clinical setting as part of the management strategy at Southampton Eye Unit and evaluate the results in the context of the current literature. Methods: A systemic literature search was performed into yoked and artificial divergence prisms for nystagmus management and summarized. This is discussed alongside a consecutive series of all successful and unsuccessful subjective prism management cases identified at Southampton Eye Unit between January 2018 and January 2025. Results: The literature is limited, with the search identifying 10 cases reports/series, 1 experimental study and 7 review articles. The case review identified 7 successful cases and 12 unsuccessful cases of prism management for nystagmus. All prism assessments were carried out in free-space in the clinic as the eye movement recordings (EMRs) were not available clinically at this site during the data set time frame. Conclusions: In our experience, the use of prism management for nystagmus does provide a positive conservative management option for some people with nystagmus. The prisms provide a relief from symptoms and can improve visual function. For others, the aberrations from the prisms themselves make the prisms hard to tolerate, especially in those with poor binocular function. It is important to relate these conclusions specifically to prism trials in free space during typical orthoptic assessments, where gold-standard EMRs were not available. This review underscores the need for further research to explore and refine the role of prism treatment in nystagmus management and determine the optimal prism strength and suitability in different forms of nystagmus. By integrating objective, precision parameters from EMRs into the clinical process of prism trials, we can work toward the development of practical clinical guidelines on prism management in nystagmus.