María Arcas-Carbonell

Parkinson’s disease (PD) is associated with visual, cognitive, and oculomotor alterations that may impair reading, highlighting the potential of eye tracking to objectively characterise these changes during a task. An observational study included 46 patients with PD, classified according to the Hoehn and Yahr (HY) scale, and 56 age- and sex-matched healthy controls. All participants underwent a comprehensive optometric examination and performed the Radner–Vissum reading test at 50 cm, while eye movements were recorded using a portable eye tracker. Fixation, saccadic, pupil diameter, and reading performance variables were analysed. PD patients showed a progressive reduction in pupil diameter (p = 0.001) and saccadic alterations, with reduced amplitude and velocity at the initial visual acuity levels (p < 0.001), whereas fixation parameters did not differ significantly between groups (p > 0.05). They also showed longer reading times, greater total reading time (84.33 ± 30.39 s vs. 37.50 ± 7.23 s; p < 0.001), lower overall scores (p < 0.001), and more reading errors (p < 0.001), whereas the logarithmic reading acuity determination (logRAD) values were comparable (p = 0.905). Overall, PD was associated with impaired reading performance and oculomotor and autonomic nervous system changes objectively measured by eye tracking during functional reading.

Background and Clinical Significance: Biallelic pathogenic variants in the PCARE gene (photoreceptor cilium actin regulator), also known as C2orf71 (chromosome 2 open reading frame 71), are typically associated with retinitis pigmentosa type 54 (RP54) and, less frequently, with cone–rod dystrophy (CORD23). Case Presentation: A 52-year-old man presented with an eight-year history of progressive visual loss, without photophobia or nyctalopia. He underwent a comprehensive ophthalmological evaluation, including multimodal retinal imaging, automated perimetry, and full electrophysiological testing, in accordance with International Society for Clinical Electrophysiology of Vision (ISCEV)’s standards. Genetic testing was performed using next-generation sequencing (NGS) with an inherited retinal dystrophy gene panel, and findings were confirmed by Sanger sequencing. Clinical examination revealed bilateral macular atrophy with minimal foveal sparing and a central scotoma. Optical coherence tomography (OCT) showed disruption of the outer retinal layers and retinal pigment epithelium (RPE) abnormalities. Fundus autofluorescence (FAF) demonstrated central hypoautofluorescence surrounded by a hyperautofluorescent ring. Electrophysiological testing revealed severely reduced rod- and cone- mediated responses on full-field electroretinography (ERG), absent pattern ERG responses, and markedly reduced multifocal ERG responses, indicating widespread retinal dysfunction with significant macular involvement. Genetic analysis identified a homozygous pathogenic nonsense variant in PCARE [c.3289C>T; p.(Gln1097*)], confirming the diagnosis of an autosomal recessive inherited retinal dystrophy. Conclusions: Biallelic PCARE variants can cause late-onset severe retinal dystrophy, with predominant macular involvement and cone–rod dysfunction. Given its phenotypic overlap with other inherited retinal diseases, accurate diagnosis requires the integration of multimodal retinal imaging, electrophysiological testing, and comprehensive genetic analysis.

Purpose: To analyse the effects of chromatic light (white, blue, red and green) and stimulus size (6/6 and 6/12) on pupil constriction, Zernike coefficients and the accommodative response curve using wavefront aberrometry across a wide age range of healthy subjects. Methods: One hundred and sixty-four right eyes from participants aged 20–75 years were evaluated. All subjects showed normal near visual function for their age. Wavefront aberrations were measured under scotopic conditions using the IRX3 aberrometer. Accommodation was induced from 0 to 10 D in the younger group and from 0 to 5 D in the full sample. Stimuli varied in colour and size. Pupil diameter and Zernike coefficients were analysed, rescaling all maps to a 3.00 and a 3.65 mm pupil, respectively. Results: Mean pupil diameter ± standard deviation decreased progressively with increasing accommodative demand by 0.51 ± 0.06 mm in the full sample (0–5 D) and by 2.09 ± 0.11 mm in the younger group (0–10 D). The greatest changes were observed under white light and larger stimuli. The Zernike component C (2,0) varied significantly across all filters, optotype sizes and in both the total ( p < 0.003) and the younger ( p < 0.0009) groups. However, C (4,0) showed significant changes in all conditions for the younger group ( p < 0.0009), particularly at higher demands. An initial overaccommodation of approximately 1 D at baseline was followed by a progressive lag beyond 5 D, being more pronounced under red light, where the accommodative response was lowest, while white light consistently elicited the strongest response. Larger stimuli induced greater responses than smaller ones, especially at high demands. Conclusion: Accommodation efficiency varies with wavelength and stimulus size: white and blue lights triggered greater pupil constriction and accommodation than red and green, with corresponding changes in defocus and spherical aberration. Small stimuli improved low-demand responses, while larger ones were more effective at higher demands.

This study describes and validates a novel method for assessing anterior crystalline lens curvature along vertical and horizontal meridians using radial measurements derived from Scheimpflug imaging. The aim was to evaluate whether pupil diameter (PD), anterior lens curvature, and anterior chamber depth (ACD) change during accommodation and whether these changes are age-dependent. A cross-sectional study was conducted on 104 right eyes from healthy participants aged 21–62 years. Sixteen radial images per eye were acquired using the Galilei Dual Scheimpflug Placido Disk Topographer under four accommodative demands (0, 1, 3, and 5 dioptres (D)). Custom software analysed lens curvature by calculating eccentricity in both meridians. Participants were analysed as a total group and by age subgroups. Accommodative amplitude and monocular accommodative facility were inversely correlated with age. Both PD and ACD significantly decreased with higher accommodative demands and age. Relative eccentricity decreased under accommodation, indicating increased lens curvature, especially in younger participants. Significant curvature changes were detected in the horizontal meridian only, although no statistically significant differences between meridians were found overall. The vertical meridian showed slightly higher eccentricity values, suggesting that it remained less curved. By enabling detailed, meridionally stratified in vivo assessment of anterior lens curvature, this novel method provides a valuable non-invasive approach for characterizing age-related biomechanical changes during accommodation. The resulting insights enhance our understanding of presbyopia progression, particularly regarding the spatial remodelling of the anterior lens surface.

Background: This study aims to evaluate subjective visual fatigue and objective optical and morphological changes in ocular structures after intermediate-duration reading on an iPad and an Ebook across different age groups. Methods: The sample included 108 right eyes from healthy subjects aged 18 to 66 years. The participants read for 20 min on an Ebook and another 20 min on an iPad under controlled illumination conditions. Aberrometry and retinal optical coherence tomography (OCT) measurements were taken before and after each reading session. Parameters such as total aberration, high-order aberration (HOA), low-order aberration (LOA), and retinal thickness in the nine Early Treatment Diabetic Retinopathy Study (ETDRS) areas were measured. The sample was analyzed as a whole and divided into five age groups by decade. Results: This study included 66 women (61.11%) and 42 men (38.89%), with an average age of 36.58 years (±14.83). The aberrometry results revealed significant differences in the total root mean square (RMS_TOTAL) after reading on both devices (p = 0.001). Low-order aberrations (RMS_LOA) also changed significantly (p = 0.001 for Ebook, p = 0.002 for the iPad), but high-order aberrations (RMS_HOA) did not. Central retinal thickness increased significantly after reading on the Ebook (p < 0.001) but not on the iPad. The peripheral retinal thickness did not change significantly. Conclusion: Moderate-duration reading increases LOA and central retinal thickness, with variations by age group and more pronounced effects from the Ebook, whereas HOA remains unaffected.

Background: Three computerized tests were designed to evaluate visual function, alertness, and visuocognitive integration under three different lighting conditions (white, red, and blue lighting). Methods: Three computerized tests were designed and programmed using the experimental design software PsychoPy version 2023.2.2. Test 1 evaluated visual acuity (VA), Test 2 assessed contrast sensitivity, and Test 3 measured alertness. This study was conducted on 53 young subjects who performed three computerized tests after adapting to each of the three different lighting conditions. A baseline aberrometric measurement was taken before and after the tests for each lighting condition. Measurements of accuracy and reaction time were taken for each test, along with total, high-, and low-order aberration values for each situation. Results: Statistically significant differences (p ≤ 0.05) were found among the different lighting conditions across the three tests, with white lighting yielding better performance in Test 1 and Test 3. Additionally, the aberrometric analysis revealed significant differences (p ≤ 0.05), with the baseline measurement being more myopic. Conclusions: White lighting produced the best VA results and faster reaction times, whereas red lighting had poorer VA effects. These findings suggest that different lighting conditions induce changes in vision and alertness, although further research is needed to understand the underlying causes.

PurposeAccommodation mainly affects the lens, a structure of the eyeball that degrades with age. The aim of this work was to study the morphological changes of different ocular structures during accommodation, both in the anterior pole and the posterior pole, which may also be involved in the accommodation process.MethodsThe study will be carried out by stimulating accommodation through lenses of -1.00, -3.00 and -5.00 D starting from the spherical equivalent (M) of each participant in different age groups, from 18 to 66 years. To obtain the M value, aberrometry was achieved, and retinal optical coherence tomography and anterior pole tomography were performed to evaluate the possible structural modifications (central and peripheral), while accommodation was progressively stimulated.ResultsIt showed that as the accommodative demand increased, morphological changes were produced in retinal thickness, both in the central and peripheral retina, in all age groups. A thinning of the retina was observed in the central 3 mm, while significant progressive thickening was observed closer to the periphery (up to 6 mm from the fovea) as the required accommodative power increased. A decrease in the anterior chamber depth (ACD) and anterior chamber volume (ACV) was observed with increasing lens power.ConclusionStructural changes were observed in the central and peripheral retina, as well as in the ACD and ACV, while progressively greater accommodation was stimulated, showing that these structures were modified in the accommodation process even in advanced presbyopes.