Vision, Volume 9, Issue 3 (September 2025) – 20 articles

This study presents a reanalysis of existing data to clarify how the visual system processes simple dynamic Glass patterns (GPs), with a particular focus on translational configurations. By combining datasets from previous studies, we apply a mixed-effects modeling approach—which offers advantages over the statistical methods used in previous studies—to investigate the contributions of pattern update rate and number of unique frames to perceptual sensitivity. Our findings indicate that the number of unique frames is the most robust predictor of discrimination thresholds, supporting the idea that the visual system integrates global form information across multiple frames—a process consistent with spatiotemporal summation. In contrast, the pattern update rate showed a weaker, though statistically significant, effect. This suggests that faster updates help preserve temporal consistency between frames, facilitating global form extraction. These results align with previous observations on complex dynamic GPs, where discrimination thresholds decrease with more unique frames, suggesting that the summation of form signals across time plays a key role in form–motion perception. By adopting a mixed-effects modeling approach, our reanalysis provides new insights into the mechanisms underlying global form perception in dynamic GPs. Full article

Combined trabeculectomy–phacoemulsification is known to provoke more inflammation and yield a poorer long-term efficacy than trabeculectomy alone. This study evaluates whether a similar trend exists for Ahmed glaucoma valve implantation when performed with or without concurrent phacoemulsification. We retrospectively analyzed 51 eyes from patients who underwent either Ahmed-Alone (n = 25) or PhacoAhmed (n = 26) surgery over a 5-year period. The primary outcomes included intraocular pressure (IOP), the use of IOP-lowering medications, and the need for further surgical intervention. Absolute success was defined as IOP reduction > 20% and IOP < 21 mmHg without medication; relative success allowed for continued pharmacologic therapy. Both groups showed a significant IOP reduction, with similar final mean IOP values (Ahmed-Alone: 14.02 ± 4.76 mmHg; PhacoAhmed: 13.89 ± 4.17 mmHg; p = 0.99) and comparable reductions in medication use (p = 0.52). Reinterventions occurred less frequently and later in the PhacoAhmed group (12% vs. 27.3%; median time: 27.1 vs. 12 months). Absolute success was not achieved in any PhacoAhmed case but occurred in 9.3% of Ahmed-Alone cases; relative success rates were similar (83.3% vs. 81.4%; p = 0.291). These findings suggest that combining phacoemulsification with Ahmed valve implantation does not significantly alter efficacy or safety profiles. Additional prospective studies are warranted to assess long-term outcomes. Full article

Our purpose is to evaluate the binocular contrast sensitivity function (CSF) in a presbyopic population and compare the results obtained with four different simultaneous-vision center-near multifocal contact lens (MCL) designs for distance vision under two illumination conditions. Additionally, chromatic CSF (red-green and blue-yellow) was evaluated. A randomized crossover pilot study was conducted. Four daily disposable lens designs, based on simultaneous-vision and center-near correction, were compared. The achromatic contrast sensitivity function (CSF) was measured binocularly using the CSV1000e test under two lighting conditions: room light on and off. Chromatic CSF was measured using the OptoPad-CSF test. Comparison of achromatic results with room lighting showed a statistically significant difference only for 3 cpd (p = 0.03) between the baseline visit (with spectacles) and all MCLs. Comparison of achromatic results without room lighting showed no statistically significant differences between the baseline and all MCLs for any spatial frequency (p > 0.05 in all cases). Comparison of CSF-T results showed a statistically significant difference only for 4 cpd (p = 0.002). Comparison of CSF-D results showed no statistically significant difference for all frequencies (p > 0.05 in all cases). The MCL designs analyzed provided satisfactory achromatic contrast sensitivity results for distance vision, similar to those obtained with spectacles, with no remarkable differences between designs. Chromatic contrast sensitivity for the red-green and blue-yellow mechanisms revealed some differences from the baseline that should be further investigated in future studies. Full article

Previous studies observed that emotional scenes, presented as distractors, capture attention and interfere with an ongoing task. This behavioral interference has been shown to be elicited by the semantic rather than by the perceptual properties of a scene, as it resisted the application of low-pass spatial frequency filters. Some studies observed that the visual system can adapt to perceptual conditions; however, little is known concerning whether attentional capture by emotional stimuli can also be modulated by the sequential repetition of viewing conditions or of emotional content. In the present study, we asked participants to perform a parity task while viewing irrelevant natural scenes, which could be either emotional or neutral. These scenes could be either blurred (low-pass filter) or perceptually intact, and the order of presentation was balanced to study the effects of sequential repetition of perceptual conditions. The results indicate that affective modulation was most pronounced when the same viewing condition (either intact or blurred) was repeated, with faster responses when perceptual conditions were repeated for neutral distractors, but to a lesser extent for emotional ones. These data suggest that emotional interference in an attentional task can be modulated by serial sensitization in the processing of spatial frequencies. Full article

Obstructive sleep apnea (OSA) is a common condition associated with intermittent hypoxia, systemic inflammation, and vascular dysfunction; mechanisms implicated in retinal disease pathogenesis. This real-world retrospective cohort study used data from the TriNetX Research Network to assess whether continuous positive airway pressure (CPAP) therapy reduces retinal disease incidence among adults with OSA and BMI between 25.0 and 30.0 kg/m². After 1:1 propensity score matching, 101,754 patients were included in the analysis. Retinal outcomes included diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal vein occlusion (RVO), and central serous chorioretinopathy (CSC). CPAP use was associated with a modest but statistically significant reduction in DR (3.2% vs. 3.4%, RR: 0.922, p = 0.016) and AMD (2.1% vs. 2.3%, RR: 0.906, p = 0.018), while no significant differences were found for RVO or CSC. These findings support prior evidence linking CPAP to improved retinal microvascular health and suggest a protective effect against specific retinal complications. Limitations include a lack of data on CPAP adherence, OSA severity, and imaging confirmation. Still, this study highlights the importance of interdisciplinary care between sleep and eye health, and the need for further prospective studies to validate CPAP’s role in preventing retinal disease progression in OSA patients. Full article

People with C3 Dense Deposit Disease (C3DDD), a rare autoimmune disease, often also have ocular complications. Due to the rarity of this disease, there is little known about ocular complications in populations across the world. This paper aimed to assess literature on retinal complications in people with C3 Dense Deposit Disease. A scoping review was conducted and three databases (Embase, Medline All, and Web of Science) were searched using agreed search terms and Boolean operators. All references were imported into Covidence for screening by two reviewers. Any conflicts were resolved by a third reviewer. Data were extracted into an Excel spreadsheet and analysis was conducted using SPSS Version 29. After full text screening, 38 studies were included in the review. These studies were from 1990–2023 and most (67%) being case reports. All studies were conducted in the United States (55%) or Europe (45%). Most studies reported drusen-like deposits in the retina (75%) and retinal pigment epithelial detachment (18%) and macular atrophy (11%). Choroidal Neovascularisation (CNV) was found in 16% of cases. People with C3 Dense Deposit Disease are at risk of ocular complications, primarily drusen-like deposits. Further population-based research and progression is needed. Full article

This report presents two cases of herpes simplex keratitis recurrence after COVID-19 mRNA vaccination in patients on herpetic prophylaxis due to recurrent herpetic keratitis. A 58-year-old man with a history of a previous penetrating keratoplasty presented with blurred vision and evidence of corneal endothelitis 48 h after the first dose of the m-RNA vaccination, and a 24-year-old male student came with a dendritic ulcer 72 h post first vaccination dose. The original prophylactic treatment of 400 mg of acyclovir twice daily was increased to five times per day for a week for both patients. The grafted patient additionally received an increase in Dexamethasone 0.1% from twice daily to four times a day. Improvement was noted within two days and documented at the weekly review, during which both patients returned to their prophylactic antiviral regime without further recurrence. At the time of their second dose of vaccination, both patients followed the same regime with an increase in treatment as per the first dose of vaccination without recurrence. Our findings suggest that patients with recurrent herpetic disease receiving prophylactic treatment need close monitoring when experiencing even subtle symptoms of recurrence and may benefit from an increase in their dose to therapeutic levels during the first days after the COVID-19 mRNA vaccination. Full article

Background: Congenital insensitivity to pain with anhidrosis (CIPA) is a rare autosomal recessive syndrome caused by loss-of-function mutations in the Neurotrophic Tyrosine Kinase Receptor 1 gene, characterized by recurrent episodes of infections and unexplained fever, anhidrosis, absence of reactions to noxious stimuli, intellectual disability, self-mutilating behaviors, and damage to many body organs, including the eyes. Main text: We systematically searched the Medline/PubMed, Scopus, and Web of Science databases from their inception until March 2025 for papers describing the clinical manifestations of patients with CIPA. The inclusion criterion was papers reporting ocular manifestations of patients diagnosed with CIPA. We excluded non-English papers or those reporting ocular manifestations of patients diagnosed with syndromes other than CIPA. Also, we excluded review articles, clinical trials, gray literature, or any paper that did not report ocular manifestations of patients with CIPA or that reported patients with previous ocular surgeries. Out of 6243 studies, 28 were included in the final analysis, comprising 118 patients. The mean age was 7.37 years, and males represented 63.5% (n = 75). Of the patients, fifty-six had bilateral ocular manifestations. The most common ocular manifestations were the absence of corneal reflex in 56 patients (47.5%, bilateral in 56), whereas corneal ulcerations were the second most common manifestation in 46 patients (38.98%, bilateral in 8), followed by corneal opacity in 32 patients (27.11%, bilateral in 19). Topical lubricants, topical antibiotics, and lateral tarsorrhaphy were common management modalities for these patients. Absent corneal sensitivity, corneal ulcers, and corneal opacities, among other manifestations, are common ocular presentations in patients with CIPA. Conclusions: Self-mutilation, intellectual disability, decreased lacrimation, and absence of the corneal reflex are factors that may explain the development of these manifestations in CIPA. The early detection of these manifestations can improve patient conditions and prevent further complications, in addition to helping to guide the clinical diagnosis of CIPA in these patients. Full article

This multicenter study evaluated the effectiveness and safety of third-generation trabecular micro-bypass implantation (iStent^® infinite) combined with phacoemulsification (n = 233 eyes). Key outcomes through 12 months included the mean change in intraocular pressure (IOP) and the number of topical medications, as well as proportions achieving IOPs ≤ 18/15/12 mmHg or using 0/1/2/ ≥ 3 medications. In all eyes with 12-month follow-up data (n = 96, consistent cohort), the mean IOP reduced from 17.2 ± 4.2 mmHg preoperatively to 13.8 ± 3.0 mmHg at Month 12 (p = 0.001), while the mean number of medications reduced from 1.24 ± 0.91 preoperatively to 0.61 ± 0.96 at Month 12 (p = 0.001). The proportions of eyes achieving IOP ≤ 18/15/12 mmHg increased from 63.5%, 34.4%, and 14.6% preoperatively to 92.7%, 71.9%, and 37.5%, respectively at Month 12, (all p = 0.001). The proportions of eyes off medication increased from 16.7% preoperatively to 62.5% at Month 12 (p = 0.001). This study provides clinically relevant, real-world results that demonstrate significant reductions in IOP and the number of topical glaucoma medications required following iStent infinite trabecular micro-bypass and phacoemulsification. Full article

Cataracts remain one of the leading causes of reversible blindness in low- and middle-income countries such as Ecuador. This study assessed the efficacy of Small Incision Cataract Surgery (SICS) and analyzed sociodemographic and clinical factors associated with postoperative visual outcomes. A retrospective multicenter analysis was conducted across six ophthalmology clinics along the Ecuadorian coast between 2023 and 2024, including 558 patients aged 30 years or older. Postoperative visual acuity, measured using the LogMAR scale, improved significantly (mean improvement of 0.525 LogMAR units in the right eye (OD) and 0.489 LogMAR units in the left eye; p < 0.001). Ages between 60 and 69 years were associated with better outcomes in the right eye, while male sex was a protective factor against poor visual acuity in the left eye. Although diabetes mellitus and hypertension were prevalent, neither condition showed a significant association with postoperative visual outcomes. The findings confirm that SICS is a safe, effective, and cost-efficient surgical approach for restoring vision in resource-limited settings, supporting its inclusion in national public health strategies to reduce avoidable blindness in developing countries. Full article

Trabeculectomy with mitomycin C is a key surgical intervention for managing glaucoma when conservative treatments fail. The success of trabeculectomy is influenced by various factors, including preoperative ocular characteristics like conjunctival vascularity. This study aims to explore the relationship between the preoperative conjunctival vascular area and post-trabeculectomy outcomes in glaucoma patients. By analyzing the conjunctival vascular density, intraocular pressure (IOP), bleb morphology, laser suture lysis (LSL) frequency, and postoperative eye drops, this research sheds light on the impact of preoperative vascularity on surgical success. Results show that lower preoperative conjunctival vessel density is associated with favorable outcomes, such as better bleb formation and reduced need for postoperative interventions, while higher conjunctival vessel density correlates with complications like hyphema. These findings emphasize the importance of assessing preoperative conjunctival vascularity to optimize trabeculectomy outcomes and personalize treatment strategies for glaucoma patients. Full article

This study analyzed the impact of corneal epithelial refraction on the correction of hyperopic and mixed astigmatism eyes treated with transepithelial photorefractive keratectomy. From the epithelial refraction provided by the diagnostic device, OCT correlations were evaluated with respect to manifest refraction. The postoperative outcomes showed a mean sphere of −0.03 D and a mean cylinder of −0.33 D, with 93% and 98% having 0.5 D, 1 D, or less spherical equivalent refractive error. The epithelium showed preoperative toricity: at 6 mm, the epithelium showed a compensational effect of ~15% for the refractive astigmatism, whereas at 3 mm, the compensation accounted for ~25% of the refractive astigmatism. No correlation was found between preoperative epithelial refraction and refractive deviation after hyperopic or mixed astigmatic transepithelial photorefractive treatment. This work provides insight into the refractive compensatory impact of the epithelium, suggests how one can benefit from that in transepithelial corrections, and sets a framework for the potential induction of errors in non-transepithelial corrections. Full article

Limbal dermoids are congenital, benign, choristomatous growths affecting the corneal-limbal junction. Conventional excision techniques often result in persistent epithelial defects, corneal thinning, and vascularization due to sectoral limbal stem cell deficiency. This study investigated a novel surgical approach for limbal dermoid excision, utilizing Bowman’s membrane lenticule and autologous limbal stem cell transplantation, aimed at improving epithelial healing and visual outcomes. Thirty-four subjects (24 females, 10 males; mean age 8.33 ± 6.47 years) with limbal dermoids underwent the procedure. After dermoid excision, a Bowman’s membrane lenticule was placed over the defect and tucked 1 mm beneath the surrounding tissue. Sectoral limbal reconstruction was then performed using the AutoSLET technique. Pre- and postoperative assessments included visual acuity, corneal thickness, and epithelialization time. Statistical analysis employed paired t-tests. The mean epithelialization time was 3.36 ± 0.74 weeks, indicating rapid healing. Best-corrected visual acuity (BCVA) significantly improved from a preoperative mean of 0.136 ± 0.121 decimal units to a postoperative mean of 0.336 ± 0.214 decimal units (p < 0.001). Corneal thickness also demonstrated a significant increase, rising from a preoperative mean of 294 ± 49.68 microns to a postoperative mean of 484 ± 5.037 microns (p < 0.001). There is a transient edema below the Bowman lenticule observed in many cases, which resolves with deposition of granulation tissue. The findings suggest that the combined use of Bowman’s membrane lenticule and autologous limbal stem cell transplantation offers a promising surgical strategy for limbal dermoid excision. This technique promotes rapid epithelialization and leads to significant improvements in visual acuity and corneal thickness compared to conventional methods. The utilization of Bowman’s membrane as a natural basement membrane and the direct application of limbal stem cells facilitate enhanced epithelial healing and visual rehabilitation. While the study is limited by its small sample size, the results demonstrate the potential of this novel approach in managing limbal dermoids effectively. Full article

Introduction: Visual impairment impacts millions of people around the world, with the vast majority of problems being treatable. Disadvantaged communities are unable to utilize the same resources to treat these problems due to a lack of knowledge or resources, in addition to the presence of barriers preventing access. The objective of this paper is to assess eye health awareness and evaluate the barriers for individuals from disadvantaged communities in order to inform future interventions and increase access to care. Methods: This is a pilot study utilizing an online anonymous questionnaire designed to assess the demographics, eye health awareness, and access to eye care of community-based patients. A comprehensive literature review was also conducted using PubMed, Scopus, and Google Scholar to evaluate barriers to eye care and methods to improve community health outcomes. The primary goal was to improve understanding of eye health awareness and access in order to inform future strategies that can help in improving eye health awareness and service availability. Results: The results indicated that 61.2% of respondents believed that eye exams are very important, and only 7.7% of participants believed that regular eye exams are not important. The majority of participants (75%) agree that regular eye exams help prevent serious eye conditions and 84.5% believe that eye health can affect quality of life. 35.6% of participants reported they had their eyes checked by a healthcare professional within the last year, while 21.2% reported never having an eye exam. Although the majority of participants found access to eye care services in their community somewhat or very easy, 8.6% and 9.5% of participants found access difficult and very difficult, respectively. Even though 45.6% of participants reported not facing any barriers regarding access to eye care, the cost of services, long waiting times, and lack of nearby eye care providers were often cited as barriers from the remainder of the participants. Moving forward, local interventions such as mobile eye clinics, public health workshops, and telehealth are viable options to obtain an understanding of the community’s health status in addition to creating opportunities to educate and provide health screenings. Conclusion: The results indicate that although there is awareness of the importance of eye health for the majority of participants, there is still a sizable minority who have insufficient understanding. Barriers to healthcare such as cost, waiting times, and proximity to providers are common problems that are preventing many from seeking eye care. Future interventions should be created to increase access and literacy amongst the community through telehealth, mobile eye clinics, and public health workshops. Additional efforts should be taken by healthcare stakeholders to enhance care delivery, implement policies, and improve awareness. Full article

Dry eye disease (DED) is a hallmark of primary Sjögren’s disease (SjD) and often resists conventional treatments like lubricant eye drops. Insulin nanoemulsions offer a potential solution by improving drug penetration and retention on the ocular surface. In animal models, insulin has shown benefits in promoting tear secretion and corneal healing. This study evaluated the safety and efficacy of insulin nanoemulsion eye drops (20 IU/mL, three times daily for 30 days) in patients with SjD. Thirty-two patients were randomized in a double-masked design to receive either insulin or placebo drops. Symptoms (assessed by OSDI questionnaire) and objective measures (tear film breakup time, corneal and conjunctival staining, and Schirmer Test) were recorded at baseline, after 4 weeks of treatment, and at a 4-week follow-up. Twenty-three participants completed the study. Both groups showed significant improvement in symptoms and objective signs after treatment (p < 0.05), but no significant differences were found between the insulin and placebo groups. No clinically relevant adverse effects were reported. Insulin nanoemulsion eye drops are safe for SjD patients, but their therapeutic advantage remains unclear. Further studies with larger samples, extended follow-up, and dose adjustments are needed to better understand their potential. Full article

Reports of individual differences in vividness of visual mental imagery (VMI) scores raise complex questions: Are Vividness of Visual Imagery Questionnaire (VVIQ) score differences actually measuring anything? What functions do these differences serve? What is their neurological foundation? A new analysis examined visual short-term memory (VSTM) and volumes of the hippocampi, primary visual cortices, and other cortical regions among vivid and non-vivid visual imagers. In a sample of 53 volunteers aged 54 to 80 with MRI scans, the performance of ten Low VVIQ scorers was compared to that of ten High VVIQ scorers. The groups included an aphantasic with a minimum VVIQ score and a hyperphantasic with a maximum VVIQ score. The study examined volumes for 12 hippocampal subfields, 11 fields implicated in visual mental imagery including area V1 and the fusiform gyrus, and 7 motor regions. In comparison to the Low VVIQ group, High VVIQ group yielded: (i) significantly more accurate VSTM performance; and (ii) significantly larger volumes of the hippocampi and primary visual cortex. Across 47 brain regions, the average volume for the High VVIQ group exceeded that of the Low VVIQ group by 11 percent. For 47 subfields, the volumes of the hphantasic exceeded those of the aphantasic person by an average of 57 percent. Females had more accurate visual short-term memory than males and younger people were more accurate than older people. The larger visual memory capacity of females was unmatched by larger regional volume differences, which suggests that the sex difference in visual memory is caused by factors other than cortical regional size. The study confirms the existence of robust empirical associations between VMI vividness, short-term memory, regional volume of hippocampal subfields and area V1. Full article

Evidence based practice enhances healthcare delivery and prevents unsafe procedures. While competency based assessments of resident cataract surgery are standard, evidence based analysis of refractive outcomes remains underutilized in educational curricula. This retrospective single center study evaluated refractive outcomes from 21 novice ophthalmology resident surgeons. Three independent groups were compared based on formal constant optimization for intraocular lens (IOL) calculation: non-optimized Haigis (n = 216), a0-optimized (n = 94), and a0/a1/a2-optimized (n = 121). All surgeries were supervised by a single attending surgeon. Mean absolute error (MAE) and the percentage of eyes within ±0.25 D and ±0.50 D of predicted spherical equivalent (SEQ) were calculated. Also, systematic bias in effective lens position (ELP) was analyzed to update manufacturer IOL constants. MAE improved from 0.44 D (non-optimized) to 0.35 D (a0-optimized p = 0.009) and 0.19 D (a0/a1/a2-optimized p < 0.001). The percentage within ±0.50 D increased from 65.7% to 74.4% to 95.0%, respectively. With ELP bias correction, updated A constant and ACD were 119.266 and 5.755 mm. a0/a1/a2-optimized outcomes were comparable to ELP bias correction for the Barrett UII, Kane, and Hill-RBF formulas. Evidence based optimization of IOL constants significantly enhances novice resident surgical outcomes, achieving parity with prediction models. A formal curriculum on IOL calculation and optimization is warranted. Full article

Pupil cycle time (PCT) estimates the dynamics of a biofeedback loop established between pupil size and stimulus luminance, size or colour. The PCT is useful for probing the functional integrity of the retinopupillary circuits, and is therefore potentially applicable for assessing the effects of damage due to retinopathies or neuropathies. In previous studies, PCT was measured by manually counting the number of pupil oscillations during a fixed period to calculate the PCT. This method is scarce, requires a good expertise and cannot be used to estimate several PCT parameters, such as the oscillation amplitude or variability. We have developed a computerised setup based on eye-tracking that expands the possibilities of characterising PCT along several dimensions: oscillation frequency and regularity, amplitude and variability, which can be used with a large palette of stimuli (different colours, sizes, shapes or locations), and further allows measuring blinking frequency and eye movements. We used this method to characterise the PCT in young control participants as well as in patients with several pathologies, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP), Stargardt disease (SD), and Leber hereditary optic neuropathy (LHON). We found that PCT is very regular and stable in young healthy participants, with little inter-individual variability. In contrast, several PCT features are altered in older healthy participants as well as in ocular diseases, including slower dynamics, irregular oscillations, and reduced oscillation amplitude. The distinction between patients and healthy participants based on the calculation of the area under the curve of the receiver operating characteristics (AUC of ROC) were dependent on the pathologies and stimuli (0.7 < AUC < 1). PCT nevertheless provides relevant complementary information to assess the physiopathology of ocular diseases and to probe the functioning of retino-pupillary circuits. Full article

The effects of Transcranial Magnetic Stimulation (TMS) depend on stimulation parameters such as intensity, location, frequency, and duration. In clinical practice, these parameters are often adapted from studies carried out in healthy individuals. However, in this narrative review, we indicate that the impact of TMS is also highly state-dependent, meaning it is influenced by the excitability of the targeted brain region at the time of stimulation. This state-dependency complicates the translation of findings from healthy individuals to clinical populations, as neurological disorders often alter brain states, limiting the applicability of standard stimulation protocols. To address this challenge, stimulation parameters must be chosen within a framework that accounts for the interaction between external stimulation and the brain’s internal state. Such an approach enhances the specificity of interventions, allowing for targeted modulation of neural populations by manipulating brain states prior to stimulation. State-dependent TMS has shown promise in conditions like cortical blindness and amblyopia, where tailored approaches based on the brain state associated with the condition have facilitated more precise and effective treatments. We advocate that integrating state-dependent knowledge tailored to the specifics of visual disorders alongside judicious selection of stimulation parameters holds the potential to establish a comprehensive paradigm for future investigations. Full article