Method to Quickly Map Multifocal Pupillary Response Fields (mPRF) Using Frequency Tagging

We present a method for mapping multifocal Pupillary Response Fields in a short amount of time using a visual stimulus covering 40° of the visual angle divided into nine contiguous sectors simultaneously modulated in luminance at specific, incommensurate, temporal frequencies. We test this multifocal Pupillary Frequency Tagging (mPFT) approach with young healthy participants (N = 36) and show that the spectral power of the sustained pupillary response elicited by 45 s of fixation of this multipartite stimulus reflects the relative contribution of each sector/frequency to the overall pupillary response. We further analyze the phase lag for each temporal frequency as well as several global features related to pupil state. Test/retest performed on a subset of participants indicates good repeatability. We also investigate the existence of structural (RNFL)/functional (mPFT) relationships. We then summarize the results of clinical studies conducted with mPFT on patients with neuropathies and retinopathies and show that the features derived from pupillary signal analyses, the distribution of spectral power in particular, are homologous to disease characteristics and allow for sorting patients from healthy participants with excellent sensitivity and specificity. This method thus appears as a convenient, objective, and fast tool for assessing the integrity of retino-pupillary circuits as well as idiosyncrasies and permits to objectively assess and follow-up retinopathies or neuropathies in a short amount of time.

From monocular photograph to angle lambda: A new clinical approach for quantitative assessment

Angle lambda assessment is essential in pediatric and strabismus practice. An abnormal angle lambda will modify the visual appearance of a strabismus or mimic one. Currently, angle lambda can be assessed by corneal topographs. Unfortunately, the use of these devices remains limited in the context of a strabismus clinic. Herein, we propose an easy, low cost, and reproducible method for angle lambda quantification, based on monocular photographs. Monocular pictures were taken by using a camera with a ring flash, centered by a fixation point. A digital evaluation analyzed the position of the corneal reflex on the pupil diameter. Using a trigonometric formula, the resulting ratio was converted into the value of angle lambda. This method was tested on 20 healthy eyes, on two successive couples of pictures, to evaluate its repeatability. Assessment using Pentacam was performed for comparison. The mean value of angle lambda was +2.61° ± 2.92° and 2.63° ± 2.85° in both picture series, respectively, and Lin's repeatability coefficient was 0.99 - with a systematic deviation of -0.071° compared to Pentacam assessment. Angle lambda distribution was in range with values from the literature. This new method allows for angle lambda assessment without requiring a specific device and can be used in strabismus and pediatric clinics.

Development and co-construction of a therapeutic patient education program for albinism

BACKGROUND

Long-term and ongoing support in accordance with the changing needs of patients and their families is one of the main components of patient care, including therapeutic patient education (TPE).

OBJECTIVE

To co-construct a TPE program for albinism with all those involved in the management of albinism patients.

METHODS

Eight steps have been defined for the co-construction process: 1) identify all the relevant experts and invite them to participate in the construction of a TPE program to improve care for and support of patients with albinism, 2) review and analyse all publications regarding TPE for albinism, 3) conduct semi-structured interviews with the patients' parents, 4) conduct brainstorming meetings with the participating experts for an exchange of experience and expertise, 5) elaborate the program's concrete content with the experts, 6) draw up a TPE skills checklist, 7) create TPE educational tools to facilitate learning, 8) review and summarize each step of the co-construction protocol.

RESULTS

Co-construction of a TPE program for children, adolescents, and young adults with albinism, and their parents.

CONCLUSION

Strengths and advantages of the co-construction process include: i) highlighting of the experiential knowledge mentioned in the repository, ii) multiplicity of points of view and perspectives, iii) rapid improvement in TPE training both for the association and the patients, iv) awareness of the shift caregivers' position with regards to TPE and recognition of the polysemy of their discourse. The TPE program for albinism has been authorized since 2018.

Extraction of Nystagmus Patterns from Eye-Tracker Data with Convolutional Sparse Coding

The analysis of the Nystagmus waveforms from eye-tracking records is crucial for the clinical interpretation of this pathological movement. A major issue to automatize this analysis is the presence of natural eye movements and eye blink artefacts that are mixed with the signal of interest. We propose a method based on Convolutional Dictionary Learning that is able to automatically highlight the Nystagmus waveforms, separating the natural motion from the pathological movements. We show on simulated signals that our method can indeed improve the pattern recovery rate and provide clinical examples to illustrate how this algorithm performs.