Influencing Factors on Pupillary Light Responses as a Biomarker for Local Retinal Function in a Large Normative Cohort.

Purpose: Investigating influencing factors on the pupillary light response (PLR) as a biomarker for local retinal function by providing epidemiological data of a large normative collective and to establish a normative database for the evaluation of chromatic pupil campimetry (CPC). Methods: Demographic and ophthalmologic characteristics were captured and PLR parameters of 150 healthy participants (94 women) aged 18 to 79 years (median = 46 years) were measured with L-cone- and rod-favoring CPC protocols. Linear-mixed effects models were performed to determine factors influencing the PLR and optical coherence tomography (OCT) data were correlated with the pupillary function volume. Results: Relative maximal constriction amplitude (relMCA) and latency under L-cone- and rod-favoring stimulation were statistically significantly affected by the stimulus eccentricity (P < 0.0001, respectively). Iris color and gender did not affect relMCA or latency significantly; visual hemifield, season, and daytime showed only minor influence under few stimulus conditions. Age had a statistically significant effect on latency under rod-specific stimulation with a latency prolongation ≥60 years. Under photopic and scotopic conditions, baseline pupil diameter declined significantly with increasing age (P < 0.0001, respectively). Pupillary function volume and OCT data were not correlated relevantly. Conclusions: Stimulus eccentricity had the most relevant impact on relMCA and latency of the PLR during L-cone- and rod-favoring stimulation. Latency is prolonged ≥60 years under scotopic conditions. Considering the large study collective, a representative normative database for relMCA and latency as valid readout parameters for L-cone- and rod-favoring stimulation could be established. This further validates the usability of the PLR in CPC as a biomarker for local retinal function.

Screening for distress and quality of life in pediatric patients after allogeneic or autologous hematopoietic stem cell transplantation using a self-reporting instrument, blood stress biomarkers and an expert rating scale (PO-Bado).

OBJECTIVE: Hematopoietic stem cell transplantation (HSCT) is highly distressing and potentially traumatizing for pediatric and young adult patients (PYAP). At present, there is little evidence on their individual burdens. METHODS: In this prospective cohort study, the course of the psychological and somatic distress was investigated on eight observation days (day -8/-12, -5, 0 (day of HSCT), +10, +20, and + 30 before/after HSCT), using the PO-Bado external rating scale and the EORTC-QLQ-C15-PAL self-assessment questionnaire. Stress-associated blood parameters were determined and correlated with the results of the questionnaires. RESULTS: A total of 64 PYAP with a median age of 9.1 years (range 0-26 years) who underwent autologous (n = 20; 31%; autoHSCT) or allogeneic (n = 44; 69%; alloHSCT) HSCT were analyzed. Both were associated with a significant reduction in QOL. The reduction in self-assessed QOL correlated with somatic and psychological distress as assessed by medical staff. While somatic distress was similar in both groups with a maximum around day+10 (alloHSCT 8.9 ± 2.4 vs. autoHSCT 9.1 ± 2.6; p = 0.69), a significantly higher level of psychological distress was seen during alloHSCT (e.g. day0 alloHSCT 5.3 ± 2.6 vs. day0 autoHSCT 3.2 ± 1.0; p < 0.0001). CONCLUSIONS: The maximum of psychological and somatic distress, as well as the lowest quality of life, ranges between day 0 and + 10 after both allogeneic and autologous pediatric HSCT. While somatic distress is similar during autologous and allogeneic HSCT, the allogeneic group seems to be affected by higher psychological distress. Larger prospective studies are needed to evaluate this observation.

Central retina plays a decisive role in the suppression of pupillary escape.

PURPOSE: To explore the pupil redilation during persistent light exposure (pupillary escape phenomenon) at the macula and periphery with monochromatic light stimuli. METHODS: Forty healthy subjects aged 18-64 years (24 females) were examined by chromatic pupil campimetry (CPC) using red and blue 4-s stimuli of 10° radius at the center and 20°-peripheral locations one per quadrant. One glaucoma patient and one achromatopsia patient served as disease models. For statistical analyses, linear mixed-effects models were performed followed by post hoc t-tests. RESULTS: A distinct pupillary escape could be demonstrated peripherally (blue 0.099%*s, red 0.153%*s); at the central healthy retina, there was no relevant escape, neither for blue nor red stimulation. Comparing central versus peripheral stimulation revealed highly significant differences in the escape (difference blue 0.100 ± 0.013, red 0.144 ± 0.013, < 0.0001, respectively). In the periphery, the escape was significantly more pronounced for red compared with blue stimulation (difference 0.054 ± 0.013; p = 0.0001). Enhanced pupillary escape outside of the 95% confidence interval of the linear mixed-effects model of the healthy population could be exemplarily shown in a patient with glaucomatous ganglion cell damage. In the achromatopsia example, no relevant escape was found for blue stimulation, but for red stimulation in the periphery in a comparable range to healthy controls. CONCLUSION: The results emphasize that an intact inner retinal network of nerve fibers arising from the central macular region is necessary for maintaining pupillary constriction during a bright 4-s light stimulus and preventing increase of pupillary escape. Increasing receptive field sizes towards the periphery on the level of retinal ganglion cells and less input from central 1:1 connections could be one of the driving mechanisms for pupillary escape.