Standards in Pupillography

The number of research groups studying the pupil is increasing, as is the number of publications. Consequently, new standards in pupillography are needed to formalize the methodology including recording conditions, stimulus characteristics, as well as suitable parameters of evaluation. Since the description of intrinsically photosensitive retinal ganglion cells (ipRGCs) there has been an increased interest and broader application of pupillography in ophthalmology as well as other fields including psychology and chronobiology. Color pupillography plays an important role not only in research but also in clinical observational and therapy studies like gene therapy of hereditary retinal degenerations and psychopathology. Stimuli can vary in size, brightness, duration, and wavelength. Stimulus paradigms determine whether rhodopsin-driven rod responses, opsin-driven cone responses, or melanopsin-driven ipRGC responses are primarily elicited. Background illumination, adaptation state, and instruction for the participants will furthermore influence the results. This standard recommends a minimum set of variables to be used for pupillography and specified in the publication methodologies. Initiated at the 32nd International Pupil Colloquium 2017 in Morges, Switzerland, the aim of this manuscript is to outline standards in pupillography based on current knowledge and experience of pupil experts in order to achieve greater comparability of pupillographic studies. Such standards will particularly facilitate the proper application of pupillography by researchers new to the field. First we describe general standards, followed by specific suggestions concerning the demands of different targets of pupil research: the afferent and efferent reflex arc, pharmacology, psychology, sleepiness-related research and animal studies

Color Pupillography in Dorsal Midbrain Syndrome.

The purpose of this study was to evaluate the pupil response to chromatic stimuli in patients with lesions in the dorsal midbrain and possibly gain new insights into the afferent pupillary pathways. Color pupillography was performed in 5 patients with dorsal midbrain syndrome (DMS), and their results were compared with those of 20 healthy control subjects. We used full-field red stimuli (605 nm) that primarily address the rod/cone system and blue stimuli (420 nm) that preferentially activate intrinsically photosensitive retinal ganglion cells (ipRGCs) directly, with a duration of 4 seconds and a stimulus intensity of 28 lx corneal illumination under mesopic conditions. One eye was stimulated, and the consensual pupil response was recorded and analyzed. The pupillary light reflex in patients with DMS was reduced, differed in shape, and showed a prolonged latency time compared to normal subjects. The blue response was less affected than the red response: the mean maximal relative amplitude (M) was 15.8% (SD = 7.8) in patients with DMS compared with 43.0% (SD = 5.5) in normal subjects for red stimulation, and M = 40.8%, SD = 8.4 (DMS) with M = 58.3%, SD = 4.8 (normals) for blue stimulation. The reduction was 63% for red stimulation but only 30% for blue stimulation in patients with DMS. Moreover, there was a preserved postillumination pupil response to blue stimulation in DMS patients. In DMS, the melanopsin-mediated ipRGC pathway appeared relatively preserved

Characteristics of peripapillary retinal nerve fiber layer atrophy in glaucoma, optic nerve sheath meningioma, and sphenoid wing meningioma

BACKGROUND/OBJECTIVES: The correct classification of a slowly progressing optic atrophy can be challenging. The aim of this work was to find out if the characteristics of peripapillary retinal nerve fiber layer (RNFL) thickness loss differ between open angle glaucoma (POAG), optic nerve sheath meningioma (ONSM), and sphenoid wing meningioma (SWM). METHODS: A total of 45 patients with POAG, ONSM, and SWM were included in the retrospective study. The peripapillary RNFL thickness measured by spectral-domain optical coherence tomography was analyzed using the Heidelberg Engineering glaucoma module(©). RESULTS: Each group consisted of 15 patients. The temporal sector of the RNFL thickness showed a median decrease of − 17 µm in glaucoma patients (range + 6/–34 µm), − 43 µm in ONSM (range − 19/ − 52 µm), and − 44 µm in SWM patients (range − 25/ − 52 µm). The RNFL thickness of the temporal sector of glaucoma patients differed significantly from the other groups (p < 0.001). All other sectors showed no significant difference between the 3 groups. CONCLUSION: The peripapillary RNFL thickness of the temporal sector of patients with beginning to moderate POAG is usually inside normal limits or borderline. In contrast, patients with ONSM and SWM are much more likely to show a considerable reduction in RNFL thickness of the temporal sector. RNFL thickness of the temporal sector marked outside normal limits occurred exclusively in meningioma patients. Considering the presence of this condition as a predictor for meningioma, sensitivity and specificity were 0.8 and 1.0, respectively. In patients with significant reduction in RNFL thickness of the temporal sector, magnetic resonance imaging of the head should be considered to rule out compression of the optic nerves. [Image: see text

Optic neuritis in German children: clinical findings and association with multiple sclerosis

Purpose!#!Analysis of a cohort of pediatric optic neuritis patients concerning the epidemiology, disease progression, and association with multiple sclerosis (MS).!##!Methods!#!Retrospective, observational cohort study. From 2004 to 2018, all electronic medical files of patients younger than 18 years referred to a tertiary care clinic in Germany with the diagnosis optic neuritis have been analyzed.!##!Results!#!Sixty-nine patients were referred in the study period, 16 did not suffer under optic neuritis and were excluded. The median visual acuity of the remaining 53 patients was 0.07 at the baseline examination and 1.0 at the latest follow-up examination (decimal notation, median 2.1 years after baseline). Forty-two percent of the patients developed MS during the study period. Female sex (p = 0.028) as well as higher age (p = 0.0082) proved to be statistically significant risk factors for MS development.!##!Conclusion!#!The prognosis for restoring vision in pediatric optic neuritis was favorable. During the observation period, the risk of developing MS was overall 42% and 8% for patients younger than 11 years. The percentage of MS as underlying cause of optic neuritis does not differ remarkably between children older 10 years and adults