In dogs, intraocular pressure (IOP) responses to topical atropine administration vary, and the anatomical basis for this variability remains unclear.

Nutmeg is a widely used culinary spice. When ingested in large quantities it has psychoactive and hallucinogenic effects.

Hyoscyamus niger (henbane) is a toxic plant containing tropane alkaloids that can cause anticholinergic toxicity. Pediatric presentations may differ from adults and may include atypical behavioral manifestations such as hyperactivity and euphoria without agitation. An 11-year-old previously healthy boy presented with sudden behavioral changes, hyperactivity, and unexplained euphoria. Approximately four hours earlier, he had ingested about one tablespoon of fresh Hyoscyamus niger seeds. Physical examination revealed minimal mydriasis and mild flushing. The patient was cooperative but disoriented, with visual hallucinations. Laboratory tests were normal, and electrocardiography showed sinus tachycardia. Findings were consistent with anticholinergic toxicity. Activated charcoal and physostigmine were not administered due to delayed presentation and absence of severe or life-threatening symptoms. Symptoms resolved completely within 24 hours with supportive care. In conclusion, Hyoscyamus niger intoxication may present predominantly with hyperactivity and euphoria without agitation, representing an atypical behavioral phenotype in pediatric patients. Plant-derived toxicities should be considered when acute behavioral changes occur, especially in rural settings.

The Superior Orbital Fissure Syndrome (SOFS) is a rare complication after craniofacial trauma. According to Hirschfeld, who first described SOFS in 1858, and Lakke, who further defined the complete SOFS, this syndrome results from damage to structures passing through the superior orbital fissure. The structures passing via the superior orbital fissure include the lacrimal nerve, nasociliary nerve, oculomotor nerve, abducens nerve, superior orbital nerve, trochlear nerve, and superior ophthalmic vein. The symptoms of supraorbital fissure syndrome are ophthalmoplegia, ptosis, extraocular muscle limitation, dilated pupil, and forehead dysesthesia. A retrospective study was performed from July 2010 to July 2017 in 2322 traumatic brain injury patients treated in the department of neurosurgery, Changzheng Hospital. A total of 39 patients with traumatic SOFS were identified based on traumatic history, symptoms, physical examinations, and image findings. According to a former retrospective study in Changzheng Hospital, their surgical decompression of SOFS was performed via orbitozygomatic approach. However, there might be a less invasive surgical approach to treat SOFS. We suggest an unusual surgical approach, the endoscopic transethmoidal approach, which might be one of the useful methods to treat SOFS.

Pupil diameter is shaped by central arousal mechanisms, autonomic drive and the biomechanical constraints of the iris. Although tonic pupil size is often treated as an index of baseline arousal, pupillary dynamics reflect partially dissociable physiological axes. We aimed to characterise this network organisation in a group of young adults and to test whether pupillary profiles can be identified within the population. Sixty-seven healthy adults (18-31 years old; 35 females) completed three pupillometric blocks under controlled ambient illumination using a Tobii Pro Fusion eye-tracker (250 Hz): fixation (2-3 min) to quantify spontaneous oscillations (hippus), a pupillary light reflex (PLR) block to characterise pupil integrity and kinematics, and dynamic emotional face videos to elicit socio-affective dilation. We extracted hippus indices (baseline, frequency, amplitude), PLR metrics (baseline, amplitude, latency, constriction velocity, recovery), and face-evoked dilation measures (baseline, amplitude, latency). Cross-parameter associations were tested using Spearman's rank correlations with correction for multiple comparisons. Robustly normalised features were then clustered using k-means, and cluster separability was assessed with one-versus-rest Receiver Operating Characteristic Curve (ROC) analyses to evaluate clustering discrimination using Area Under Curve (AUC). Tonic measures of pupil activity were strongly coupled across paradigms, with hippus baseline correlating with baseline during face videos. Baseline pupil diameter was also associated with reflex amplitudes, consistent with a peripheral contribution. Clustering revealed three distinct profiles with good discrimination (AUC > 0.80): a high-tonus/fast profile (short PLR latency, high constriction velocity), a hypo-reactive profile (low tonic level with attenuated PLR and face responses), and a slow/hyper-dilated profile (delayed PLR kinetics with large face-evoked dilation). Overall, pupil dynamics grouped into three profiles, consistent with an interplay between the tonic central state, autonomic kinematics and iris-related mechanical constraints. This classification cautions against single-mechanism interpretations of pupillary measures, supports individual stratification, and motivates multimodal studies to disentangle central arousal from peripheral gain.

During dark adaptation, pupil size changes in association with visual adaptation processes; however, the influence of diurnal phase (daytime vs nighttime) and aging on these changes remains unclear. In this study, we examined pupil size changes during dark adaptation across the daytime and nighttime in young, middle-aged, and aged C57BL/6N mice. In young mice, pupil size reached a maximum shortly after the onset of dark adaptation and then gradually decreased during the daytime, whereas it remained dilated during the nighttime. Furthermore, dopamine depletion induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) significantly attenuated the gradual pupillary constriction following pupil dilation during dark adaptation in the daytime, suggesting a possible involvement of dopaminergic signaling in the later phase of the response. In middle-aged mice, pupillary light reflex-evoked constriction was preserved; however, the early (rapid) phase of constriction following the initial dilation during daytime dark adaptation was impaired, whereas the later (delayed) phase remained largely comparable to that in young mice, suggesting age-related alterations in regulatory mechanisms rather than a loss of constriction capacity. Pharmacological analyses further suggested that distinct neural mechanisms may differentially contribute to these temporal phases. In aged mice, maximal pupil dilation during dark adaptation was significantly reduced during both the daytime and nighttime. In addition, aged mice exhibited distinct abnormalities in pupil dilation immediately after the onset of dark adaptation during the nighttime, indicating mechanisms that differ from those observed in middle-aged mice. Together, these results demonstrate that pupillary dynamics during dark adaptation are modulated by diurnal phase and progressively altered with aging. Thus, analysis of pupil dynamics during dark adaptation may provide a useful approach for detecting age-related changes in neural function.

A 22-year-old female patient was referred for glaucoma evaluation due to an unclear bilateral ocular condition. For 6 months she had experienced glare sensitivity and dilated pupils without visual impairment. Initially, bilateral anterior uveitis with elevated intraocular pressure (IOP) had been diagnosed and treated locally with topical steroids and latanoprost. Clinical examination revealed bilateral diffuse iris transillumination defects with irregular, nonreactive mydriasis as well as heavily pigmented anterior chamber angles. Extended medical history revealed pneumonia treated with systemic moxifloxacin 2 weeks prior to symptom onset. Based on this correlation, the diagnosis of bilateral acute iris transillumination syndrome (BAIT) was established, which is a rare and likely underdiagnosed syndrome that is frequently mistaken for uveitis or pigment dispersion syndrome. Although the pathogenesis has not yet been fully clarified, associations with moxifloxacin therapy and respiratory tract infections have been described. Middle-aged women are predominantly affected. Clinically, the acute phase is characterized by conjunctival hyperemia combined with loss of the iris pigment epithelium, resulting in acute pigment dispersion into the anterior chamber. Subsequently, irreversible diffuse iris transillumination defects and enlarged atonic pupils develop. Pigment deposition within the anterior chamber angle can lead to ocular hypertension and rarely a secondary glaucoma. Careful history taking, regular IOP monitoring and symptomatic treatment of photophobia are essential. Awareness of this syndrome prevents unnecessary, time-consuming and costly uveitis work-up.

While many animals display behaviours resembling social conventions when interacting with conspecifics, it is unknown whether animals who live in close contact with humans develop sensitivity to our social conventions. With an eye-tracking study (N = 39), we asked whether dogs' (Canis familiaris) eye movements and pupil sizes would show a reaction when observing a violation in the customary response to human conventional communicative gestures ("come here" and "go away"). In the video stimuli, a human actress either approached or walked away from a second human actress. Both these actions (approaching or walking away) could be expected or surprising (within-subject), depending on whether they happened in response to the "come here" or the "go away" gesture of the second actress. While dogs' looking times and number of gaze transitions between the two actresses did not differ significantly between congruent and incongruent responses, their pupil size changes did: dogs' pupils dilated more when watching the incongruent responses (approaching after the "go away" gesture and walking away after the "come here" gesture) compared to the congruent ones. We discuss the possibility that pet dogs, during their ontogeny, implicitly form expectations about the usual response to some conventional human gestures. These expectations are not self-centred, as they were evidenced when dogs observed a third-party interaction between two humans, and they are context-specific, as the same responses elicited surprise following one gesture but not the other. We also consider alternative explanations and limitations of our findings.

Pourfour du Petit syndrome (PdPS) is a rare oculosympathetic hyperactivity syndrome characterized by ipsilateral mydriasis, eyelid retraction, and hyperhidrosis. We report a case of a 36-year-old female who presented to the emergency department with a chief complaint of a dilated pupil with photosensitivity and blurred vision in the left eye (OS). On examination, the best corrected visual acuity was 20/20 in both eyes (OU). Anisocoria was observed with the right pupil measuring 4 mm in the dark and 2 mm in the light and the larger left pupil measuring 6 mm in the dark with minimal constriction in the light. There was no relative afferent pupillary defect (RAPD). Magnetic resonance angiography (MRA) and digital subtraction angiogram (DSA) of the head showed a 7 mm left paraclinoid ICA aneurysm. Neurovascular neurosurgery placed a flow diverting stent into the left ICA. Repeat DSA demonstrated near-complete resolution of the left ICA ophthalmic segment aneurysm status post-flow diversion. At the last follow-up one year later, the patient was stable clinically and radiographically with no further recurrences. Clinicians should be aware that anisocoria can be a potentially life-threatening presentation of intracranial vascular lesions.

Recurrent painful ophthalmoplegic neuropathy (RPON) is characterized by recurrent unilateral headache associated with ipsilateral ophthalmoplegia due to palsy of one or more ocular cranial nerves, including the oculomotor, trochlear, and abducens nerves. Herein, we report a case of RPON with frequent recurrence over a short period, wherein further recurrence was prevented using high-dose riboflavin. The patient was a 6-year-old boy who presented with a 3-day history of headache, right eye pain, vomiting, and right oculomotor nerve palsy. He had a similar episode 3 years earlier, which resolved spontaneously after 1 month. Initial treatment with intravenous methylprednisolone alleviated eye pain, ocular motility disorder, and ptosis, but not the dilated pupil. Despite steroid treatment, the patient experienced frequent relapses triggered by infectious diseases, resulting in side effects such as moon face and weight gain. High-dose riboflavin (200 mg/day) was initiated as prophylaxis after other treatments, including lower doses of riboflavin and sodium valproate, failed to prevent relapses. The patient remained relapse-free for 9 months after increasing the riboflavin dose. Although it remains unclear whether high-dose riboflavin alone or in combination with valproic acid was effective, this case suggests that high-dose riboflavin might be an effective prophylactic treatment for RPON.