We aimed to evaluate the types and concentrations of trace elements in tears of individuals living in urban and rural environments using particle induced X-ray emission (PIXE) and the possible association with exposure to air pollution and suggest a novel method for tear-based biomonitoring studies. This cross-sectional pilot study comprised 42 healthy subjects, 28 living in a rural area and 14 in an industrial city. Tears were collected with Schirmer paper and characterized by PIXE. Trace element concentrations from both eyes were averaged together with environmental pollution data. Main outcome measures were between-group differences in types and concentrations of trace elements in tears and comparison to environmental data. The rural group included 12/28 men, mean age 45.2 ± 14.8 years. The urban group consisted of 11/14 men of mean age 27 ± 5.9 years. Six rural and all urban were active smokers. Air pollution data showed more toxic elements in the rural environment. On PIXE analysis, chlorine, sodium, and potassium were found in similar concentrations in all samples. Normalizing to chlorine yielded higher values of aluminum, iron, copper, and titanium in the rural group; aluminum was found only in the rural group. The higher levels of certain trace elements in the rural group may, in part, be a consequence of exposure to specific environmental conditions. No direct association was found with air pollution data. PIXE is useful to analyze trace elements in tears, which might serve as a marker for individual exposure to environmental pollutants in biomonitoring studies.

Objective: To identify the elemental composition of ovine tears using particle‐induced X‐ray emission (PIXE). Animals Studied: Ten physically healthy female sheep. Procedures: Tear samples were collected using Schirmer tear test strips. Tear samples were collected once daily over five consecutive days to assess reproducibility. Elemental analysis was performed with PIXE. Data were processed with GUPIX software. Median values of the elements identified were calculated and statistically analyzed with Kruskal–Wallis and post hoc Dunn's tests. Results: The analysis demonstrated consistent elemental concentrations over the 5‐day sampling period. Among the elements detected, chloride (Cl) and sodium (Na) exhibited the highest concentrations. Conclusions: This study establishes PIXE as a valuable technique for detecting and analyzing the elemental composition of the tear film in sheep. By providing a precise method for elemental analysis in small biological samples, this approach lays the groundwork for future research exploring its reliability and sensitivity in tear analysis and potential as a biomarker for ocular and systemic health. The impact of variables including age, diet, and environmental exposure on tear film constituents should be studied, potentially extending the methodology to other species.

Background/Objectives: To simplify diagnosing congenital and acquired nystagmus using fundus photographs. Methods: A retrospective study included patients with congenital or childhood-acquired nystagmus examined at a hospital-based ophthalmology clinic (September 2020–September 2023) with fundus photos taken. Exclusions were for incomplete data or low-quality images. Demographics, aetiology, orthoptic measurements, and ophthalmologic and neurological exams were reviewed. Two independent physicians graded fundus photos based on amplitude (distance between “ghost” images), the number of images visible, and the direction of nystagmus. Severity was rated on a 0–3 scale using qualitative and quantitative methods. Photographic findings were compared to clinical data, and statistical analysis used Mann-Whitney tests. Results: A total of 53 eyes from 29 patients (16 females, 13 males; mean age 12.5 years, range 3–65) were studied: 25 with binocular nystagmus and 3 with monocular nystagmus. Diagnoses included congenital (n = 15), latent-manifest (n = 3), neurologically associated (n = 2), and idiopathic (n = 9). Types observed were vertical (n = 5), horizontal (n = 23), rotatory (n = 10), and multidirectional (n = 15). Visual acuity ranged from 20/20 to no light perception. Fundus photos correlated with clinical diagnoses, aiding qualitative assessment of direction and amplitude and mitigating eye movement effects for clearer retinal detail visualization. Conclusions: Fundus photography effectively captures nystagmus characteristics and retinal details, even in young children, despite continuous eye movements. Integrating fundus cameras into routine practice may enhance nystagmus diagnosis and management, improving patient outcomes.