Foveal Changes Research Articles

Symptomatic Foveal Impingement following Posterior Vitreous Detachment Formation

A-57-year old visually asymptomatic healthy woman was examined by us first in 2016. On optical coherence tomographic (OCT) examination left foveal contour appeared as normal at that time (Figure A). In 2020, there was the evidence of vitreomacular adhesion despite the normal foveal contour in the left eye (Figure B). However, we noticed the left foveal inpingement related to detached posterior vitreous on OCT when she was reexamined with the complaint of left metamorphosia in 2024 (Figure C). Posterior vitreous detachment (PVD) is the vitreous gel liquefaction,and extracellular matrix changes at the vitreoretinal interface characterized with the detachment of posterior vitreous cortex from the internal limiting membrane due to ongoing aging process.1 Gel liquefaction that exceeds the degree of vitreoretinal dehiscence may end up with anomalous PVD. We propose the term of ‘foveal inpingement’ to describe the subtle foveal contour change described above and believe that this term can gain recognition among the retinal physicians.

Evaluation of foveal avascular zone changes in patients with type 1 diabetes using optical coherence topography angiography

Aim To evaluate vascular changes in the foveal avascular zone in pediatric patients with type 1 diabetes by using optical coherence tomography angiography (OCTA). Patients and methods This cross-sectional study was performed in Benha University Hospital at Department of Ophthalmology. The patients were obtained from the Pediatric Endocrinology Clinic in Benha University Hospital. The study was conducted on 48 patients (96 eyes) divided into two groups: group A, 24 diabetic children with type 1 diabetes, group B, 24 healthy children of the same age and sex who met the inclusion criteria. The patients were collected from April 2022 to April 2023. The patients were photographed using the Optovue AngioVue OCTA System. Results Our results show that according to the foveal avascular zone it was slightly wider in type 1 diabetic cases with no clinically evident diabetes retinopathy (DR) than control. There were insignificant differences between the two groups as regards foveal density, but as regards foveal thickness, it was significantly lower in diabetic cases than in the control group. Conclusion We discovered that OCTA could consistently identify microvascular changes in the Deep and Superficial Capillary Plexus prior to the clinical indications’ onset of DR. In order to assess the OCTA potential for the screening of DR in children with T1DM, it is necessary to conduct numerous prospective studies.

Visual Function and Foveal Avascular Zone Changes in Patients with Diabetic Macular Edema After Intravitreal Injection of Ranibizumab

Visual Function and Foveal Avascular Zone Changes in Patients with Diabetic Macular Edema After Intravitreal Injection of Ranibizumab

Foveal Changes after Uneventful Phacoemulsification Surgery for Senile Nuclear Cataract

Objective: To describe foveal thickness and foveal anatomical changes after uneventful phacoemulsification surgery. Design: Interventional case control study. Participants: Both eyes of healthy phakic patients presenting to the American University of Beirut Medical Center Eye clinic for phaco-emulsification surgery in one eye (the study eye). The fellow eye served as control. Methods: OCT images of the macula were taken pre-operatively, then on a weekly basis for 12 weeks post-operatively. Outcomes: post op foveal thickness and morphological changes. Results: From the originally recruited 66 patients, 52 patients (104 eyes) completed the study. A transient increase in foveal thickness was observed in 36/52 (69%) eyes mostly between weeks 4 and7 post operatively. Twenty-seven eyes developed anatomic changes including: microcysts in 15 eyes (55%), regular cysts in 6 eyes (22%), and epiretinal membranes in 6 eyes (11.5%). Changes appeared as early as 1 week post operatively, and lasted on the average 4 weeks. Conclusion: Uncomplicated cataract surgery can lead to transient thickening of the macula as well as morphological changes.

Cellular Determinants of Visual Outcomes in Eyes with Epiretinal Membrane: Insights from Adaptive Optics OCT

Objective or PurposeIn this study, we aimed to evaluate cellular alterations in the foveal neuroglia of eyes with idiopathic epiretinal membrane (ERM) and examine their correlation with visual function. We also aimed to identify prognostic markers for visual outcomes post-vitrectomy. DesignA prospective longitudinal study. Subjects, Participants, and/or ControlsThe study comprised 84 subjects, including 50 eyes diagnosed with idiopathic ERM and 34 healthy eyes serving as controls. MethodsThe foveal neuroglial changes in eyes with idiopathic ERM were determined using adaptive optics optical coherence tomography (AO-OCT) by comparing them with healthy eyes. For patients with ERM, the ERM and inner limiting membrane were removed during vitrectomy in all eyes. Main Outcome MeasuresFoveal microstructures on AO-OCT images, best-corrected visual acuity (BCVA) and M-CHARTS scores, evaluated preoperatively and at 1, 3, and 6 months postoperatively, and associations between foveal neuroglial changes and these parameters. ResultsAO-OCT revealed discernible differences in the foveal cones of the eyes with ERM and their healthy counterparts. The thickness of the ellipsoid zone (EZ) band was augmented in eyes with ERM. The alignment of the Müller cells was more vertical, and the density of the foveal cone cell nuclei was higher in eyes with ERM than in healthy eyes. Within the AO-OCT parameters, the higher cone nuclei count correlated with worse M-CHARTS scores, both preoperatively and 6 months postoperatively (P = 0.004, 0.010, respectively). Greater EZ thickness was significantly associated with poorer 6-month postoperative BCVA (P = 0.005). ConclusionsAO-OCT can be used to precisely identify cellular alterations in eyes with ERM that are closely related to visual function impairments. These cellular insights enhance our understanding of ERM pathology and offer promising prognostic indicators of visual outcome after vitrectomy.

Phenotypic characteristics of Danish patients with achromatopsia.

To describe the phenotype of Danish patients with genetically verified achromatopsia (ACHM) with special focus on signs of progression on structural or functional parameters, and possible genotype-phenotype correlations. Forty-eight patients were identified, with disease-causing variants in five different genes: CNGA3, CNGB3, GNAT2, PDE6C and PDE6H. Longitudinal evaluation was possible for 11 patients and 27 patients participated in a renewed in-depth phenotyping consisting of visual acuity assessment, optical coherence tomography (OCT), fundus autofluorescence, colour vision evaluation, contrast sensitivity, mesopic microperimetry and full-field electroretinography. Foveal morphology was evaluated based on OCT images for all 48 patients using a grading system based on the integrity of the hyperreflective photoreceptor band, the inner segment ellipsoid zone (ISe). Signs of progression were evaluated based on longitudinal data and correlation with age. We found a statistically significant positive correlation between OCT grade and age (Spearman ρ = 0.62, p < 0.0001) and we observed changes in the foveal morphology in 2 of 11 patients with ≥5 years of follow-up. We did not find any convincing correlation between age and functional parameters (visual acuity, retinal sensitivity and contrast sensitivity) nor did we find correlation between structural and functional parameters, or any clear genotype-phenotype correlation. Some patients with ACHM demonstrate signs of progressive foveal changes in OCT characteristics with increasing age. This is relevant in terms of possible new treatments. However, functional characteristics, such as visual acuity, remained stable despite changing foveal structure. Thus, seen from a patient perspective, ACHM can still be considered a non-progressive condition.

Visual Field Deficits in Albinism in Comparison to Idiopathic Infantile Nystagmus.

This is the first systematic comparison of visual field (VF) deficits in people with albinism (PwA) and idiopathic infantile nystagmus (PwIIN) using static perimetry. We also compare best-corrected visual acuity (BCVA) and optical coherence tomography measures of the fovea, parafovea, and circumpapillary retinal nerve fiber layer in PwA. VF testing was performed on 62 PwA and 36 PwIIN using a Humphrey Field Analyzer (SITA FAST 24-2). Mean detection thresholds for each eye were calculated, along with quadrants and central measures. Retinal layers were manually segmented in the macular region. Mean detection thresholds were significantly lower than normative values for PwA (-3.10 ± 1.67 dB, P << 0.0001) and PwIIN (-1.70 ± 1.54 dB, P<0.0001). Mean detection thresholds were significantly lower in PwA compared to PwIIN (P<0.0001) and significantly worse for left compared to right eyes in PwA (P=0.0002) but not in PwIIN (P=0.37). In PwA, the superior nasal VF was significantly worse than other quadrants (P<0.05). PwIIN appeared to show a mild relative arcuate scotoma. In PwA, central detection thresholds were correlated with foveal changes in the inner and outer retina. VF was strongly correlated to BCVA in both groups. Clear peripheral and central VF deficits exist in PwA and PwIIN, and static VF results need to be interpreted with caution clinically. Since PwA exhibit considerably lower detection thresholds compared to PwIIN, VF defects are unlikely to be due to nystagmus in PwA. In addition to horizontal VF asymmetry, PwA exhibit both vertical and interocular asymmetries, which needs further exploration.

Association of foveal avascular zone change and glaucoma progression

Background/aimsTo investigate the association between longitudinal changes of foveal avascular zone (FAZ) area and the rate of structural and functional progression in glaucoma.MethodsA longitudinal cohort included 115 eyes (46 glaucoma...

Potential application of foveal structural measurements in treatment decision for retinopathy of prematurity: an OCT-based study

PurposeTo investigate foveal changes in infants with ROP not requiring treatment(nROP) and ROP infants needing treatment (tROP) using a handheld SD-OCT device.MethodWe performed horizontal SD-OCT scans through the fovea in 156 eyes of 81 infants diagnosed with ROP. Foveal immaturity indices including the presence of inner retinal layers (IRL), absence of foveal outer nuclear layers widening (ONL) and attenuation of hyperreflective outer segment layers (OS), presence and type of cystoid macular edema (CME), epiretinal membrane (ERM), foveal pit depth (FPD), foveal pit width (FPW) and central foveal thickness (CFT) were calculated. The multivariate logistic regression model was used to predict the need for treatment based on OCT measurements.ResultsThe shape of the foveolar pit was not significantly different among tROP and nROP groups (P-value = 0.287, Chi-square test). IRL extrusion was incomplete in both tROP and nROP groups (P-value = 0.0.41, Chi-square test). Nevertheless, the presence of thicker IRL was more frequent in the nROP group in comparison with the tROP group (100% vs.64.8%, P-value = 0.001). CME was observed in 29% of eyes in the tROP group and 40% of eyes in the nROP group; however, this difference was not statistically significant (P-value = 0.32, Chi-square test). ERM was detected in 15 (75%) and 84 (65.6%) eyes in the nROP and tROP groups, respectively (P-value = 0.39, Chi-square test). Multivariate logistic regression analyses showed that the need for treatment was significantly associated with gestational age (GA), CFT and FPD (P-values 0.001 and 0.002 respectively).ConclusionsThis study demonstrated GA, foveal pit depth and the central foveal thickness could accurately predict the need for treatment with sensitivity, specificity, and diagnostic accuracy of 97%, 65% and 91.7% respectively.

Presumed Müller Cell Activation in Multiple Evanescent White Dot Syndrome.

The purpose of this study was to investigate the foveal changes occurring in multiple evanescent white dot syndrome (MEWDS) using multimodal imaging techniques with a specific focus on hyper-reflective dots (HRDs). This was a retro-prospective observational study including 35 eyes with active MEWDS. Structural and en face optical coherence tomography (OCT) was performed, with follow-up visits at 2 weeks, 6 weeks, and 2 months from baseline. HRD percentage area (HRD % area) was calculated in a 600 µm fovea centered circle on en face OCT, after background subtraction and image binarization. HRD % area was compared with 23 fellow control eyes. Longitudinal changes in the HRD % areas were assessed using repeated-measure statistics. HRDs were observed as scattered hyper-reflective spots on the vitreoretinal interface on en face OCT images, colocalizing with HRDs or vertical hyper-reflective lines on structural OCT images. The baseline evaluation showed a significantly higher HRD % area in MEWDS eyes compared to fellow eyes (0.10 ± 0.03 vs. 0.08 ± 0.04, P = 0.01). The HRD% area correlated positively with LogMAR visual acuity and inversely with the duration of symptoms. Longitudinal analysis revealed a significant reduction in the HRD % area over time. There was no significant interaction between the rate of HRD disappearance and clinical or demographic factors at baseline. As HRD potentially represents the end-feet projections of activated Müller cells on the retinal surface, this study supports the involvement of Müller cells in the pathogenesis of the disease. The findings highlight the potential of en face OCT imaging for monitoring the progression of MEWDS.

IMPG2-Related Maculopathy

PurposeTo investigate the phenotype, variability and penetrance of IMPG2-related maculopathy. DesignRetrospective observational case series. MethodsClinical evaluation, multimodal retinal imaging, genetic testing, and molecular modeling. ResultsTwenty-five individuals with a mono-allelic IMPG2 variant were included, 5 of whom were relatives of patients with IMPG2-associated retinitis pigmentosa. In 17 individuals (median age, 52 years; range, 20-72 years), a distinct maculopathy was present and included foveal elevation with or without subretinal vitelliform material or focal atrophy of the retinal pigment epithelium. Best corrected visual acuity (BCVA) was ≥ 20/50 in the better eye (n=15) and 5 patients were asymptomatic. Longitudinal observation (n=8, up to 19 years) demonstrated stable maculopathy (n=3), partial/complete resorption (n=4) or increase (n=1) of the subretinal material, with overall stable vision (n=6). The remaining 8 individuals (median age, 58 years; range, 43-83 years; BCVA ≥ 20/25) showed no manifest maculopathy and were identified through segregation analysis. All 8 were asymptomatic, with minimal foveal changes observed on optical coherence tomography in 3 cases. Eighteen different variants were detected, 11 of them truncating. Molecular modeling of five missense variants, c.727G>C, c.1124C>A, c.2816T>A, c.3047T>C and c.3193G>A supported the hypothesis that these have a loss-of-function effect. ConclusionsMono-allelic IMPG2 variants may result in haplo-insufficiency manifesting as a maculopathy with variable penetrance and expressivity. Family members of patients with IMPG2-related retinitis pigmentosa may present with vitelliform lesions. The maculopathy often remains limited to the fovea and is usually associated with moderate visual impairment.

Prognostic factors for visual recovery after successful large macular hole surgery using the inverted flap technique

The goal of our study is to describe the functional results and preoperative factors predicting visual recovery after successful inverted flap technique and closure of large full-thickness macular holes (FTMH) and to evaluate the correlations between microstructural foveal changes and final visual acuity. Retrospective, descriptive, analytical study including 80eyes of 78patients with large FTMH; operated by inverted flap technique with successful closure of the macular hole after surgery. All eyes underwent a full preoperative ophthalmic examination and macular B-scan SD-OCT. We performed the classic inverted flap technique for all patients. Postoperatively, all patients were examined at 7days, 1, 3, 6, 9 and 12months after surgery. SD-OCT was performed for all patients on each follow-up. Preoperatively, best-corrected visual acuity (BCVA), FTMH size and basal hole diameter were the main outcome measures. Postoperatively, BCVA, macular thickness, integrity of the external limiting membrane (ELM) and ellipsoid zone (EZ) were recorded. Mean age was 62±8.42years with female predominance. Mean size of the FTMH was 692.59μm, and mean basal hole diameter was 1436.06μm. Mean BCVA improved from 1.06±0.491 LogMAR preoperatively to 0.52±0.32 at 9months following surgery (P<0.001). At 9months, the ELM was absent, partial or fully restored in 6.67, 10 and 83.33% respectively. The EZ was absent, partial or fully restored in 6.67, 33 and 63.33% respectively. ELM regeneration always preceded EZ regeneration at every point of follow-up. Final BCVA was statistically correlated with initial hole size (P=0.006, OR=1.056; CI [1.016-1.098]) and mean symptom duration prior to surgery (P=0.001. OR=0.987; CI [0.976-0.998]). Analysis of the ROC curve demonstrated that a hole diameter>478.5μm and symptom duration>5weeks were correlated with non-improvement of visual acuity, with 81.3% sensibility and 18.7% specificity. We report tomographic microstructural foveal changes and functional results following successful large idiopathic FTMH surgery using the classic inverted flap technique. Preoperative parameters such as initial FTMH diameter and mean symptom duration prior to surgery are crucial prognostic factors influencing final visual results.

X-linked juvenile retinoschisis associated with an RS1 in-frame deletion and bilateral central serous chorioretinopathy.

To report the case of a patient with X-linked juvenile retinoschisis (XLRS), caused by an in-frame deletion of the RS1 gene, who presented visual loss due to bilateral central serous chorioretinopathy (CSC).Methods: Observational case report. A 34-year-old man, with type-A personality, presented with a one-month history of decreased visual acuity and metamorphopsia in his right eye. Funduscopic examination showed a dome-like foveal elevation in both eyes (OU), as well as subtle pigmentary changes of the retinal pigment epithelium with a tapetal reflex in the fovea. Spectral-domain optical coherence tomography revealed intraretinal cystic foveal changes and serous retinal detachment in OU. Fundus fluorescein angiography of OU showed a focal area of intense hyperfluorescence with leakage in late phases. Electroretinogram revealed a markedly attenuated b-wave and a diminished a-wave in photopic and scotopic phases. Genetic testing revealed a hemizygous c.282_284delCTT deletion in the RS1 gene, predicting a p.Ser95del change at the protein level. The patient was diagnosed with XLRS and central serous chorioretinopathy as a coexisting condition. Patient was observed during a 3-month period but showed no improvement. Therefore, subthreshold micropulse laser was applied, achieving complete resolution of signs and symptoms of CSC. CSC can be a cause of acute or subacute visual loss in patients with XLRS when other complications such as vitreous hemorrhage and retinal detachment have been excluded.

Clinical features and imaging characteristics in achiasmia.

Achiasmia is a rare visual pathway maldevelopment with reduced decussation of the axons in the optic chiasm. Our aim was to investigate clinical characteristics, macular, optic nerve and brain morphology in achiasmia. A prospective, cross-sectional, observational study of 12 participants with achiasmia [8 males and 4 females; 29.6 ± 18.4 years (mean ± standard deviation)] and 24 gender-, age-, ethnicity- and refraction-matched healthy controls was done. Full ophthalmology assessment, eye movement recording, a high-resolution spectral-domain optical coherence tomography of the macular and optic disc, five-channel visual-evoked responses, eye movement recordings and MRI scans of the brain and orbits were acquired. Achiasmia was confirmed in all 12 clinical participants by visual-evoked responses. Visual acuity in this group was 0.63 ± 0.19 and 0.53 ± 0.19 for the right and left eyes, respectively; most participants had mild refractive errors. All participants with achiasmia had see-saw nystagmus and no measurable stereo vision. Strabismus and abnormal head position were noted in 58% of participants. Optical coherence tomography showed optic nerve hypoplasia with associated foveal hypoplasia in four participants. In the remaining achiasmia participants, macular changes with significantly thinner paracentral inner segment (P = 0.002), wider pit (P = 0.04) and visual flattening of the ellipsoid line were found. MRI demonstrated chiasmatic aplasia in 3/12 (25%), chiasmatic hypoplasia in 7/12 (58%) and a subjectively normal chiasm in 2/12 (17%). Septo-optic dysplasia and severe bilateral optic nerve hypoplasia were found in three patients with chiasmic aplasia/hypoplasia on MRI. In this largest series of achiasmia patients to date, we found for the first time that neuronal abnormalities occur already at the retinal level. Foveal changes, optic nerve hypoplasia and the midline brain anomaly suggest that these abnormalities could be part of the same spectrum, with different manifestations of events during foetal development occurring with varying severity.

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration.

A progression sequence for age-related macular degeneration (AMD) learned from optical coherence tomography (OCT)-based multimodal (MMI) clinical imaging could add prognostic value to laboratory findings. In this work, ex vivo OCT and MMI were applied to human donor eyes prior to retinal tissue sectioning. The eyes were recovered from non-diabetic white donors aged ≥80 years old, with a death-to-preservation time (DtoP) of ≤6 h. The globes were recovered on-site, scored with an 18 mm trephine to facilitate cornea removal, and immersed in buffered 4% paraformaldehyde. Color fundus images were acquired after anterior segment removal with a dissecting scope and an SLR camera using trans-, epi-, and flash illumination at three magnifications. The globes were placed in a buffer within a custom-designed chamber with a 60 diopter lens. They were imaged with spectral domain OCT (30° macula cube, 30 µm spacing, averaging = 25), near-infrared reflectance, 488 nm autofluorescence, and 787 nm autofluorescence. The AMD eyes showed a change in the retinal pigment epithelium (RPE), with drusen or subretinal drusenoid deposits (SDDs), with or without neovascularization, and without evidence of other causes. Between June 2016 and September 2017, 94 right eyes and 90 left eyes were recovered (DtoP: 3.9 ± 1.0 h). Of the 184 eyes, 40.2% had AMD, including early intermediate (22.8%), atrophic (7.6%), and neovascular (9.8%) AMD, and 39.7% had unremarkable maculas. Drusen, SDDs, hyper-reflective foci, atrophy, and fibrovascular scars were identified using OCT. Artifacts included tissue opacification, detachments (bacillary, retinal, RPE, choroidal), foveal cystic change, an undulating RPE, and mechanical damage. To guide the cryo-sectioning, OCT volumes were used to find the fovea and optic nerve head landmarks and specific pathologies. The ex vivo volumes were registered with the in vivo volumes by selecting the reference function for eye tracking. The ex vivo visibility of the pathology seen in vivo depends on the preservation quality. Within 16 months, 75 rapid DtoP donor eyes at all stages of AMD were recovered and staged using clinical MMI methods.

A CROSS-SECTIONAL, OBSERVATIONAL AND ANALYTICAL STUDY TO DETERMINE TOTAL MACULAR VOLUME AND FOVEAL RETINAL THICKNESS IN PREGNANT WOMEN

INTRODUCTION: Owing to the hemodynamic changes due to hormones during pregnancy, multiple anatomical, physiological and biochemical changes occur in all systems. These changes are transient in nature but may cause permanent damage if not caught early. To evaluate Total Macular Volume a PURPOSE: nd Foveal Retinal Thickness in 3rd trimester Pregnancy between (Normal Pregnant, Pregnancy Induced Hypertensives, Gestational Diabetics) and to compare these values with healthy non-pregnant females of the same age matched group. A total of 140 eyes of 70 patients were evaluated for Total m METHODOLOGY: acular volume and foveal retinal thickness changes using OCT (3D Macula scan) and the results were compared by ANOVA and Paired-T test (SPSS software, version-26.0). Notable difference was noted in Total macular volume and Foveal ret RESULTS: inal thickness between pregnant and nonpregnant. Also, notable difference noted between 3rd trimester healthy pregnant, gestational diabetics and pregnancy induced hypertensives (p value &lt;0.05). Pregnancy summated with Diabetes / Hypertension may lead to permane CONCLUSION: nt damage. Hence awareness and screening of pregnant females' post-partum is necessary.

A variation of foveal morphology in a group of children with hypermetropia.

During routine eye examinations, we noticed widened and flattened foveal pits with loss of normal V-shaped foveal profile and a pseudohole-like appearance in some otherwise healthy hypermetropic children. Our purpose was to describe clinical significance and multimodal imaging features of this incidental finding. Prospectively, 25 eyes of 13 hypermetropic children with these foveal changes and 36 eyes of 19 hypermetropic children with normal foveal appearance were enrolled. The macular thickness measurements and foveal parameters including pit diameter, depth, base, and area obtained by optical coherence tomography (OCT) (Heidelberg Spectralis, Heidelberg Engineering, Heidelberg, Germany), macular superficial and deep vessel density (VD) and foveal avascular zone values obtained by optical coherence tomography angiography (Avanti RTVue‑XR; Optovue, Fremont, CA, USA) were noted. The correlations of these parameters with visual function were evaluated. In the study group, significantly widened and flattened pit contours with decreased central foveal thickness (p = 0.01), and increased distance between foveal edges (p < 0.001) were observed. While the whole image superficial macular VD was similar between the groups (p = 0.74), a significant decrease in deep macular VD was observed in the study group (p = 0.01). None of these changes were correlated with visual acuity. Wider and flattened foveal pits described here represent a newly defined variation in healthy hypermetropic children. Although a correlation with visual acuity was not evident, these changes in foveal profile are shown to be related with macular microvascular changes in deep capillary plexus. Awareness of these morphologic changes will help clinicians in the differential diagnosis of macular pseudohole.

Attentional allocation and the pan-field color illusion.

Humans subjectively experience a scene as rendered in color across the entire visual field, a visual phenomenon called "pan-field color" (Balas & Sinha, 2007). This experience is inconsistent with the limited color sensitivity in the peripheral visual field. We investigated the effects of visual attention allocated to the peripheral visual field on the pan-field color illusion. Using "chimera" stimuli in which color was restricted to a circular central area, we assessed observers' tendency to perceive color throughout images with achromatized peripheral regions. We separately analyzed sensitivity and response bias in judging the color content of the scene image as full-color, chimera, or gray. Using a dual-task paradigm, we manipulated observers' attentional allocation by controlling the stimulus presentation time of the central task, making the foveal attentional load change. The slope of the foveal load-sensitivity function suggests that attention was modulated by foveal load even in the peripheral visual field. Bias was affected by the size of the central colored area, such that the tendency to answer "full-color" to the chimera image increased with eccentricity. Based on these effects of attention on sensitivity and bias, we suggest that the pan-field color illusion cannot be fully explained by the decrease of sensitivity that is modulated by attentional allocation in the periphery. Our results rather indicate that the pan-field color illusion at least partly reflects a liberal bias in peripheral vision.

Ocular alterations in patients with Alport syndrome-An update

Alport syndrome (AS) is arare hereditary systemic disease that results in alterations of the kidneys, inner ear, and various structures of the eye. It is caused by mutations in one of the genes encoding collagen typeIV. In recent years, new and innovative imaging techniques have added characteristics of ocular alterations in AS and provided new insights, including into the pathogenesis of the disease. The aim of this paper is to provide an overview of the current knowledge of ocular changes in AS, as well as to present the Alport ocular pass. Narrative review article. Ocular manifestations of AS include changes in the cornea, lens, and retina. Specifically, posterior polymorphic corneal dystrophy, anterior lenticonus (pathognomonic for AS), and various retinal changes have been described, which have been further characterized in recent years by newer imaging techniques. In particular, foveal changes in AS may present as both athickened central retina in the context of foveal hypoplasia or astaircase-like thinning of the fovea. Both lesions could provide further insights into the role of typeIV collagen in ocular structures. The AS can manifest in various structures of the eye. The staircase-like changes of the central retina in AS patients indicate the important role of collagen typeIV in the homeostasis and regular function of the inner retinal layers. The often mild foveal hypoplasia may provide clues to the role of collagen typeIV in retinal embryogenesis. While anterior lenticonus is pathognomonic for AS and can be treated easily by refractive lens exchange, the only option currently available for retinal alterations is close follow-up and, if necessary, treatment of systemic complications of AS.

Novel phenotype–genotype correlation with PEX6 gene in Saudi patients with Heimler syndrome

AbstractPurpose: Peroxisome biogenesis disorders (PBDs; MIM# 601539) are heterogeneous disorders caused by defects in genes encoding proteins that are essential for peroxisomal matrix and membrane proteins. Heimler syndrome is one of PBDs that is caused by mutations in PEX1 and PEX6 genes. In this study, we aimed to fully characterize the clinical and molecular aspects of two Saudi probands who were diagnosed early as Usher syndrome.Methods: We set up a comprehensive clinical and molecular genetic workflow including detailed ophthalmological, audiological and systemic assessments followed by genome‐wide SNP microarrays analysis and targeted PEX6 gene screening by Sanger sequencing.Results: Clinically: both patients appeared dysmorphic with long faces, high forehead, short nose, small low set ears, and full lips. The ophthalmological assessment revealed advanced inherited retinal dysfunction represented by waxy pallor optic disc, attenuated vessels, RPE mottling with intraretinal bony spicules pigmentations and central foveal atrophic changes in both eyes. Both Indexes exhibited bilateral sensory neural hearing loss and amelogenesis imperfecta. Genetically: an autozygous block was identified on chromosome 6p21.1 encompassing PEX6 gene using SNP microarrays. Novel PEX6 (NM_000287.3) c.290 T &gt; G (p.Val97Gly) was found by Sanger sequencing. The identified variant co‐segregated with the phenotype in both families and found to be “likely pathogenic” according to ACMG guidelines.Conclusions: Our study represents the first report of PEX6 associated Heimler syndrome in the middle east and considered to be the third in the literature so far. It highlights the importance of combining molecular diagnosis with the clinical findings to expand our knowledge of PEX6‐related PBDs phenotype and the allelic spectrum for this gene.