Retinal Structural Changes Research Articles

P0208 Can we predict inflammatory activity of Ulcerative Colitis by just looking into eyes?

Abstract Background With the introduction of Optical Coherence Tomography-Angiography(OCT-A) in ophthalmology it has been suggested that the true prevalence of posterior segment manifestations in patients with Inflammatory Bowel Diseases(IBD) may be higher than previously thought and OCT-A findings would correlate with the inflammatory burden of the IBD[1-4]. In this prospective study, the relationship with retinal vascular structures and choroidal changes in patients with Ulcerative Colitis(UC) were investigated. Methods 47 UC patients and 42 healthy volunteers with a similar age-sex distribution were employed in this study. Epidemiological, clinical and biochemical data were recorded and patients were grouped as active (55%, n=26) and remission (45%, n=21) according to Mayo Scores. All participants underwent right-left eye anterior and posterior segment examinations, but only right eye data were used. Retinal vascular structures were evaluated on 6x6 mm sections with OCT-A, while choroidal thickness was assessed using the EDI mode of the spectral-domain Optical Coherence Tomography. All measurements were made at similar times of the day to avoid changes due to diurnal rhythm. Results No evidence of past or active uveitis was detected in all participants. It is found that the foveal avascular zone area was enlarged and the subfoveal choroidal thickness was increased in UC patients, compared to the findings of healthy participants(p<0.05). In addition, serum CRP, ESR and fibrinogen levels were generally increased in the active group compared to the remission group and had significant linear relationships with disease activity(p<0.05). No significant relationship was found between the obtained posterior segment eye findings and disease activity, serum CRP, ESR and fibrinogen(p>0.05). Conclusion Retinal vascular structure changes in UC patients compared to healthy participants were associated with systemic inflammation leading to ischemic damage. While choroidal atrophy and thinning were expected with ischemia in UC patients, an increase in subfoveal choroidal thickness was observed in our patients. Furthermore, the study showed that posterior segment eye findings were not superior to traditional biomarkers routinely used in clinical practice in assessing disease activity. References 1-Yilmaz S, Aydemir E, Maden A, Unsal B. The prevalence of ocular involvement in patients with inflammatory bowel disease. Int J Colorectal Dis. 2007;22(9):1027-1030. doi:10.1007/s00384-007-0275-1 2-Felekis T, Katsanos K, Kitsanou M, et al. Spectrum and frequency of ophthalmologic manifestations in patients with inflammatory bowel disease: a prospective single-center study. Inflamm Bowel Dis. 2009;15(1):29-34. doi:10.1002/ibd.20584 3-Nakayama LF, Bergamo VC, Conti ML, et al. The retinal foveal avascular zone as a systemic biomarker to evaluate inflammatory bowel disease control. Int J Retina Vitreous. 2019;5:16. Published 2019 Aug 6. doi:10.1186/s40942-019-0168-9 4-Debourdeau E, Charmard C, Carriere I, et al. Retinal Microcirculation Changes in Crohn’s Disease Patients under Biologics, a Potential Biomarker of Severity: A Pilot Study. J Pers Med. 2022;12(2):230. Published 2022 Feb 7. doi:10.3390/jpm12020230

Anatomical and functional changes after internal limiting membrane peeling.

Internal limiting membrane (ILM) peeling has been an acceptable step in vitrectomy surgeries for various retinal diseases such as macular hole, chronic macular edema following epiretinal membrane (ERM), and vitreoretinal traction. Despite all the benefits, this procedure has some side effects, which may lead to structural damage and functional vision loss. Light and dye toxicity may induce reversible and irreversible retina damage, which will be observed in postoperative optical coherence tomography scans. Retinal nerve fiber layer damage is attributed to ganglion cell degeneration and axonal transport alteration, and dissociated optic nerve fiber layer is due to Müller cell damage. Eccentric MHs and recurrence of previous MHs may also lead to vision loss. Iatrogenic retinal damage may cause structural retinal changes without significant vision loss or progression to choroidal neovascularization. The mechanism of persistent macular edema after membrane peeling is still unclear, but it has been related to tractional trauma and blood-retina barrier damage. The reappearance of ERM is another cause of decreased vision after ILM peeling, which might be secondary to incomplete membrane removal. In glaucoma patients, ILM peeling is associated with significantly worsening the mean deviation on the visual field test after the surgery. We discussed various causes of vision loss and structural changes following ILM peeling. These causes may be attributed to the surgical procedure itself or the associated steps, instruments, and dyes used during the ILM peeling procedure.

CAMK2D and Complement Factor I-Involved Calcium/Calmodulin Signaling Modulates Sodium Iodate-Induced Mouse Retinal Degeneration.

To investigate the effect of Ca2+/calmodulin-dependent protein kinase II (CAMKII) δ subtypes (CAMK2D) on sodium iodate (NaIO3)-induced retinal degeneration in mice. Bioinformatics analysis and Western blot experiments were used to screen the significantly differentially expressed genes in age-related macular degeneration (AMD) disease. CAMK2D knockdown and overexpression models were constructed by lentivirus (LV) infection of adult retinal pigment epithelial cell line-19 (ARPE-19) cells in vitro. Flow cytometry was used to detect ARPE-19 cell apoptosis induced by NaIO3. In vivo, CAMK2D knockdown and overexpression mouse models were generated by infecting mouse retinal pigment epithelium (RPE) with adeno-associated virus (AAV). Retinography, optical coherence tomography (OCT), and histological analysis (hematoxylin and eosin staining) were used to detect NaIO3-induced retinal structural changes in mice. Electroretinography (ERG) was used to detect NaIO3-induced retinal function changes in mice. TdT-mediated dUTP nick-end labeling (TUNEL) staining was used to detect the apoptosis of retinal cells induced by NaIO3. RNA sequencing (RNA-Seq) and bioinformatics analysis were used to screen for target genes affected by CAMK2D in CAMK2D-overexpressing ARPE-19 cells. And flow cytometry, OCT, and ERG were used to evaluate the regulatory effect of CAMK2D on target genes. Bioinformatics analysis found the expression of genes related to Ca2+ signal was significantly reduced in AMD patients. Western blot showed that in a mouse model of dry AMD induced by NaIO3, CAMK2D expression in RPE-Choroid tissue significantly lower than normal mice. In vitro, our results showed that overexpression of CAMK2D in ARPE-19 cells decreased apoptosis induced by NaIO3 and knockdown increased apoptosis. In vivo, CAMK2D overexpression in RPE cells can attenuate the retina degeneration induced by NaIO3 and CAMK2D knockdown aggravated degeneration. The bioinformatics analysis indicated that CAMK2D might affect AMD pathology through complement factor I (CFI). In vitro, knockdown of CFI in ARPE-19 cells increased apoptosis induced by NaIO3. In knockdown CFI ARPE-19 cells, overexpression of CAMK2D reduced the above apoptosis. In mice retina, CFI knockdown can aggravate the retina degeneration induced by NaIO3. In knockdown CFI mice, overexpression of CAMK2D in RPE can attenuate the above retina degeneration. Western blot confirmed that CAMK2D regulated the expression of CFI in mice. CAMK2D can attenuate the retinal degeneration induced by NaIO3, which was achieved by regulating the CFI.

Multimodal Longitudinal Optical Imaging Reveals Optic Neuritis Preceding Retinal Pathology in Experimental Autoimmune Encephalomyelitis.

Inflammatory demyelinating diseases of the CNS, chief among them multiple sclerosis (MS), are a major cause of disability in young adults. Early manifestations of MS commonly involve visual dysfunction, which is often caused by optic neuritis and is accompanied by quantifiable structural changes of the anterior visual pathway. Retinal optical coherence tomography (OCT) has emerged as an important tool for clinical assessment of these structural alterations, but the underlying pathobiological mechanisms and temporal dynamics are yet poorly understood at a cellular level. Using the experimental autoimmune encephalomyelitis (EAE) model of MS in fluorescent reporter mouse strains for neuronal function and innate immune cells, we use a unique combination of retinal intravital 2-photon microscopy (2PM) and OCT. In this fashion, we elucidate the spatiotemporal interplay of functional and structural retinal changes over the course of 1 month after EAE induction, with histopathologic imaging validating main results. While all mice display histologic signs of optic neuritis early after EAE induction and independently of motor symptom severity, retinal signs of neuronal stress and parenchymal immune activation spike well after clinical peak of disease, with no signs of lasting structural damage appearing within 1 month after EAE induction. Thus, local retinal endpoints appear to be functions of downstream axonal damage rather than of immediate immune activation directed at the retina. However, as early as 1 week after EAE induction, retinal 2PM can detect recruitment of perivascular immune cells towards the optic nerve (ON), providing the earliest sign of disease activity in otherwise clinically inconspicuous mice. Our work identifies the recruitment of CX3CR1+ cells to the ON as an early sign of disease underlining the importance of combined structural and functional retinal imaging for the spatiotemporal characterization of neuroinflammatory and neurodegenerative processes. It further proposes retinal phagocyte orientation, morphology, and abundance as potential surrogate markers for neurodegenerative activity.

Comparative retinal study by OCT in Alzheimer's disease: Insights from the APP NL‐F/NL‐F model

Aims/Purpose: Transgenic mouse models of Alzheimer's disease (AD) have shown a correlation between retinal abnormalities and brain pathology. The APPNL‐F/NL‐F murine humanized AD model accurately replicates many pathological features seen in AD patients. This study aims to analyze, using manual retinal segmentation by optical coherence tomography (OCT), the changes occurring in several retinal layers in the APPNL‐F/NL‐F AD model at 6, 9, 12, 15, 17, and 20 months of age, in comparison to C57BL/6J mice (WT).Methods: A diachronic study was conducted using OCT for manual retinal segmentation to evaluate changes in retinal layers. The analysis focused on retinal thickness in the retinal nerve fiber layer (RNFL)‐ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), and outer nuclear layer (ONL) based on Early Treatment Diabetic Retinopathy Study (ETDRS) sectors. The study included both the APPNL‐F/NL‐F AD model and age‐matched WT controls, with measurements taken at 6, 9, 12, 15, 17, and 20 months.Results: Both the APPNL‐F/NL‐F model and WT animals exhibited changes in retinal thickness at various study time points. WT mice showed significant changes in the INL, OPL, and ONL. In contrast, the AD model exhibited significant changes in all analyzed retinal layers except for the IPL. The APPNL‐F/NL‐F model displayed significant thickness variations in the retinal layers analyzed, which closely resemble those found in humans during pre‐clinical, as well as mild and moderate stages of AD.Conclusions: The study identifies early retinal vascular and structural changes in the APPNL‐F/NL‐F model that precede cognitive changes observed at later stages. These findings suggest that the retinal changes in this model more closely resemble those in human AD compared to other transgenic models, highlighting the potential of retinal assessments in early AD diagnosis.

Assessing retinal thickness and vascular structures in an Alzheimer's disease mouse model app NL‐F/NL‐F

Aims/Purpose: In Alzheimer's disease (AD), there are histopathological aspects that cannot be studied in patients, demanding the use of murine models of the disease. The APPNL‐F/NL‐F model reproduces the pathophysiology quite faithfully. The aim of the present study was to analyze the retinal vascular structures and retinal thickness in an AD model at different ages and compares these findings to age‐matched wild type (WT) controls.Methods: A diachronic study was conducted using spectral‐domain OCT angiography (SD‐OCTA) and AngioTool software to assess retinal vascular structures, alongside OCT for measuring inner and outer retina thickness. We include two study groups: the APPNL‐F/NL‐F AD model and WT controls at 6, 9, 12, 15, 17, and 20 months old. The analysis focused on the three vascular plexus and retinal thickness, using the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors. We considered statistically significant a p‐value < 0.05.Results: Compared to WT, the APPNL‐F/NL‐F group exhibited both vascular and structural changes starting as early as 6 months, with these changes persisting and evolving at 15, 17, and 20 months. Significant vascular alterations, particularly in the superficial vascular complex (SVC), were noted. There was a marked decrease in vessel area and total vessel length in the SVC, as well as in the intermediate and deep capillary plexus. Additionally, the inner retina predominantly showed a thickness decrease, while the outer retina demonstrated an increased thickness at most time points compared to the control group.Conclusions: The study identifies early retinal vascular and structural changes in the APPNL‐F/NL‐F model that precede cognitive changes observed at later stages. These findings suggest that the retinal changes in this model more closely resemble those in human AD compared to other transgenic models, highlighting the potential of retinal assessments in early AD diagnosis.

Assessing retinal thickness and vascular structures in an Alzheimer's disease mouse model APP NL‐F/NL‐F

Aims/Purpose: In Alzheimer's disease (AD), there are histopathological aspects that cannot be studied in patients, demanding the use of murine models of the disease. The APPNL‐F/NL‐F model reproduces the pathophysiology quite faithfully. The aim of the present study was to analyze the retinal vascular structures and retinal thickness in an AD model at different ages and compares these findings to age‐matched wild type (WT) controls.Methods: A diachronic study was conducted using spectral‐domain OCT angiography (SD‐OCTA) and AngioTool software to assess retinal vascular structures, alongside OCT for measuring inner and outer retina thickness. We include two study groups: the APPNL‐F/NL‐F AD model and WT controls at 6, 9, 12, 15, 17, and 20 months old. The analysis focused on the three vascular plexus and retinal thickness, using the Early Treatment Diabetic Retinopathy Study (ETDRS) sectors. We considered statistically significant a p‐value < 0.05.Results: Compared to WT, the APPNL‐F/NL‐F group exhibited both vascular and structural changes starting as early as 6 months, with these changes persisting and evolving at 15, 17, and 20 months. Significant vascular alterations, particularly in the superficial vascular complex (SVC), were noted. There was a marked decrease in vessel area and total vessel length in the SVC, as well as in the intermediate and deep capillary plexus. Additionally, the inner retina predominantly showed a thickness decrease, while the outer retina demonstrated an increased thickness at most time points compared to the control group.Conclusions: The study identifies early retinal vascular and structural changes in the APPNL‐F/NL‐F model that precede cognitive changes observed at later stages. These findings suggest that the retinal changes in this model more closely resemble those in human AD compared to other transgenic models, highlighting the potential of retinal assessments in early AD diagnosis.

Evaluation of the retinal vascular and structural changes in migraine patients treated with anti‐CGRP monoclonal antibodies

Evaluation of the retinal vascular and structural changes in migraine patients treated with anti‐CGRP monoclonal antibodies

Structural changes in the retina and choroid in patients with different degrees of myopia

To observe the structural changes of retina and choroid in patients with different degrees of myopia. We recruited 219 subjects with different degrees of myopia for best corrected visual acuity, computer refraction, intraocular pressure, axial length (AL), optical coherence tomography (OCT) imaging, and other examinations. Central macular retinal thickness (CRT), subfoveal choroidal thickness (SFCT), nasal retinal thickness (NRT), temporal retinal thickness (TRT), nasal choroidal thickness (NCT) and temporal choroidal thickness (TCT) were measured by optical coherence tomography. ImageJ software was used to measure the retinal area and choroidal area (CA), and Niblack was used to binarize all OCT images to measure the choroidal vessel area (CVA) and choroidal matrix area (CMA). We found that CRT, SFCT, NRT, TRT, NCT, TCT, CA, CVA, and CMA were significantly reduced in the pathological myopia (PM) group. AL was negatively correlated with NRT, SFCT, CMA, CVA and choroidal stromal index. There was a significant positive correlation between AL and choroidal vascular index. The choroidal vascular index in the PM group was significantly increased compared with the other groups. We established a univariate receiver operating curve to analyze the diagnostic value of all parameters for PM. Spherical equivalent, AL, SFCT, TCT, NCT, CA, CVA, and CMA had high diagnostic value for PM, among which CMA had the highest accuracy. There are changes in choroidal structure in adults with different degrees of myopia. Choroidal thickness, CVA and CMA decrease significantly with the increase of myopia, and are correlated with AL. The decrease of CMA has higher diagnostic value in myopia.

Variabilities in Retinal Hemodynamics Across the Menstrual Cycle in Healthy Women Identified Using Optical Coherence Tomography Angiography.

Background: Numerous conditions, both physiological and pathological, can influence changes in the retinal vascular architecture. In order to be able to highlight pathological aspects of systemic diseases with ocular activity, it is necessary to understand how physiological fluctuations can influence circulation at the retinal level. The present study attempts to evaluate retinal and choroidal vascular and structural changes in healthy female subjects over the course of a menstrual cycle using OCT-A. Methods: We analyzed 22 eyes from healthy reproductive women with a regular menstrual cycle. We performed five OCT-A scans of the subjects every 7-8 days over the course of a month starting from the first day of the menstrual cycle and ending with the first day of the next cycle, measuring perfusion density in the superficial and deep vascular plexuses, choroidal thickness, and FAZ perimeter. Results: There are physiological variations in retinal hemodynamics that can be identified using OCT-A, choroidal thickness having statistically significant increased values in the parafoveal nasal sector during the ovulatory phase (289.18 µm) compared to the early follicular phase (281.9 µm), and the subfoveal sector during the ovulatory phase (319.04 µm) compared to the early follicular phase (308.27 µm). Conclusions: These findings along with abnormally small FAZ perimeters indicate that the menstrual cycle phase should be considered whenever interpreting OCT-A results. Further studies that include larger cohorts, control groups, and hormone serum levels are necessary to confirm and correlate retinal vascular alterations and the phase of the menstrual cycle using OCT-A.

Corrigendum to “Football-related concussions and head impacts are associated with changes in retinal structure and signaling” [Biomark. Neuropsychiatry 10 (2024) 100091

Corrigendum to “Football-related concussions and head impacts are associated with changes in retinal structure and signaling” [Biomark. Neuropsychiatry 10 (2024) 100091

Longitudinal Assessment of Structural and Functional Changes in Rod-cone Dystrophy: A 10-year Follow-up Study

Emerging clinical trials for inherited retinal disease (IRD) require an understanding of long-term progression. This longitudinal study investigated the genetic diagnosis and change in retinal structure and function over 10 years in rod-cone dystrophies (RCDs). Longitudinal observational follow-up study. Individuals initially diagnosed with retinitis pigmentosa who underwent baseline assessment between 2010 and2013. Baseline and follow-up assessments included best-corrected visual acuity (VA), Goldmann visual field (GVF) perimetry, spectral-domain OCT imaging, electroretinogram, and panel-based genetic testing. Linear mixed models were used to investigate disease progression and interaction between progression rate and baseline measurement. Interocular symmetry in disease progression was assessed using intraclass correlation coefficients (ICCs). Change in VA, GVF area, and ellipsoid zone (EZ) width over 10 years in RCD. A total of 23 participants attended follow-up (mean age 63±15 years at follow-up; 48% female), with 20 classified as having RCD and 3 reclassified as having cone-rod dystrophy based on genetic diagnosis. At 10-year follow-up, only 60% of RCD participants showed progression of ≥15 letters in either or both eyes, and 40% did not meet the criteria in either eye. Between the eye with poorer versus better VA at baseline, high symmetry in disease progression was observed for GVF area (ICC=0.87; 95% confidence interval [CI]: 0.68-0.95), and moderate interocular symmetry in disease progression was observed for VA (ICC=0.50 [95%CI: 0.07-0.77]) and EZ width (ICC=0.64 [95% CI: 0.25-0.85]). Baseline values influenced progression for VA and percentage change in GVF area, whereas total percentage change in EZ width did not differ across baseline values. Many individuals with RCD did not have a significant 15-letter decline in VA over a 10-year follow-up, highlighting the challenges of relying on VA as a measure of disease progression. Symmetry between eyes varies, emphasizing a key consideration for selection of outcome measures in IRD clinical trials. Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

ROPRNet: Deep learning-assisted recurrence prediction for retinopathy of prematurity

Retinopathy of Prematurity (ROP) recurrence is significant for the prognosis of ROP treatment. In this paper, corrected gestational age at treatment is involved as an important risk factor for the assessment of ROP recurrence. To reveal the complementary information from fundus images and risk factors, a dual-modal deep learning framework with two feature extraction streams, termed as ROPRNet, is designed to assist recurrence prediction of ROP after anti-vascular endothelial growth factor (Anti-VEGF) treatment, involving a stacked autoencoder (SAE) stream for risk factors and a cascaded deep network (CDN) stream for fundus images. Here, the specifically-designed CDN stream involves several novel modules to effectively capture subtle structural changes of retina in the fundus images, involving enhancement head (EH), enhanced ConvNeXt (EnConvNeXt) and multi-dimensional multi-scale feature fusion (MMFF). Specifically, EH is designed to suppress the variations of color and contrast in fundus images, which can highlight the informative features in the images. To comprehensively reveal the inherent medical hints submerged in the fundus images, an adaptive triple-branch attention (ATBA) and a special ConvNeXt with a rare-class sample generator (RSG) were designed to compose the EnConvNeXt for effectively extracting features from fundus images. The MMFF is designed for feature aggregation to mitigate redundant features from several fundus images from different shooting angles, involving a designed multi-dimensional and multi-sale attention (MD-MSA). The designed ROPRNet is validated on a real clinical dataset, which indicate that it is superior to several existing ROP diagnostic models, in terms of 0.894 AUC, 0.818 accuracy, 0.828 sensitivity and 0.800 specificity.

Retina in Clinical High-Risk and First-Episode Psychosis.

Abnormalities in the retina are observed in psychotic disorders, especially in schizophrenia. Using spectral-domain optical coherence tomography, we investigated structural retinal changes in relatively metabolic risk-free youth with clinical high-risk (CHR, n = 34) and first-episode psychosis (FEP, n = 30) compared with healthy controls (HCs, n = 28). Total retinal macular thickness/volume of the right eye increased in FEP (effect sizes, Cohen's d = 0.69/0.66) and CHR (d = 0.67/0.76) compared with HCs. Total retinal thickness/volume was not significantly different between FEP and CHR. Macular retinal nerve fiber layer (RNFL) thickness/volume of the left eye decreased in FEP compared with HCs (d = -0.75/-0.66). Peripapillary RNFL thickness was not different between groups. The ganglion cell (GCL), inner plexiform (IPL), and inner nuclear (INL) layers thicknesses/volumes of both eyes increased in FEP compared with HCs (d = 0.70-1.03). GCL volumes of both eyes, IPL thickness/volume of the left eye, and INL thickness/volume of both eyes increased in CHR compared with HCs (d = 0.64-1.01). In the macula, while central sector thickness/volume decreased (d = -0.62 to -0.72), superior outer (peri-foveal) sector thickness/volume of both eyes increased (d = 0.81 to 0.86) in FEP compared with HCs. The current findings suggest that distinct regions and layers of the retina may be differentially impacted during the emergence and early phase of psychosis. Consequently, oculomics could play significant roles, not only as a diagnostic tool but also as a mirror reflecting neurobiological changes at axonal and cellular levels.

Retinal Function in Young Adults Following Topical Application of Levodopa to the Eye.

Levodopa has been investigated as a therapeutic solution for ocular disorders involving dysregulation of the dopaminergic system, especially in the context of myopia. However, given the critical role dopamine plays in normal vision, this phase I trial examined whether levodopa/carbidopa eye drops induce any regional changes in retinal structure and function. Twenty-nine healthy male subjects 18 to 30 years of age were randomly assigned to receive either a low (1.4/0.34 µmoles/day, n = 14) or high (2.7/0.68 µmoles/day, n = 15) dose of levodopa/carbidopa eye drops in 1 eye for 28 consecutive days. A placebo solution was applied to all fellow eyes. Measures included visual acuity, regional frequency doubling perimetry, regional multifocal electroretinogram (mfERG) and optical coherence tomography (retinal thickness). Outcome measures were undertaken at baseline, end-of-treatment (4 weeks), and at a follow-up (4 months post-treatment). For low dose treated eyes, regional analysis showed a small, statistically significant change in mfERG recordings (increase in ring 5 amplitude in low dose treated eyes, P < 0.05) and the retinal thickness map (localized retinal thinning in low dose treated eyes, P < 0.05). These changes were not clinically significant. No significant changes were observed in high dose treated eyes. Pharmacokinetic analysis (rabbits) demonstrated that levodopa was not detectable within blood and peaked within the eye at 15 to 30 minutes (and eliminated within 4 hours). No clinically significant effects of levodopa/carbidopa eye drops were found with regard to normal retinal structure and function following short-term use. This study further demonstrates the safety of topical levodopa, which may support its use in the treatment of ocular disorders in which the dopamine system is dysregulated.

Changes in macular ganglion cell and retinal nerve fiber layer thickness during recovery from infection with the B.1.1.7 variant of SARS-CoV-2 in previously hospitalized patients with COVID-19 bilateral pneumonia.

Coronavirus disease 2019 (COVID-19) has been associated with various systemic complications, including potential impacts on ocular health. Recent studies have suggested that COVID-19 may lead to changes in retinal structure, particularly in the neuroretinal and retinal nerve fiber layers (RNFL). This study aimed to examine changes in neuroretinal and RNFL of the optic dics based on optical coherence tomography (OCT) in patients hospitalized due to COVID-19 bilateral pneumonia at 2 time points after discharge. A prospective study involved 49 patients with COVID-19 bilateral pneumonia hospitalized between March and May 2021. Baseline ocular evaluations were conducted 2 months post-discharge, with follow-up examinations 6 months later. Retinal parameters, including RNFL and ganglion cell layers (GCL), were assessed. Control group of healthy individuals also underwent similar ophthalmic examinations for comparative analysis. We found that the average thickness of the retinal nerve fiber layer (RNFL) of the optic disc was lower in the COVID-19 group than in controls (p≤0.01). The ganglion cell layer (GCL) was thicker in the inner inferior ring (p=0.008) but thinner in the outer superior, outer nasal, and outer inferior rings (p=0.044, p<0.01, and p<0.01, respectively). OCT parameters were assessed according to sex. At 6 months, the RNFL of the inner inferior and outer temporal rings was thinner in women than in men (p=0.022 and p=0.020, respectively). The GCL of the inner temporal and outer temporal rings was also thinner in women than in men (p=0.004 and p=0.005, respectively). In conclusion: at 6-month follow-up, RNFL and GCL thickness was significantly lower in some areas of the retina compared with baseline. COVID-19 seems to cause changes in the macular retina, highlighting the need for ophthalmologic screening of patients with a history of SARS-CoV-2 infection.

Retinal morphology and microvasculature density alterations in generalized anxiety disorders

Purpose This study evaluates morphological alterations in the macula and peripapillary regions of patients with Generalized Anxiety Disorder (GAD) using optical coherence tomography (OCT) and OCT angiography (OCT-A). We compared these changes with healthy controls to determine GAD’s impact on the retina. Methods An observational case-control study was conducted from January to May 2024 at the Benghazi Teaching Eye Hospital, including 40 GAD patients and 40 healthy controls aged 30–65 years. Participants underwent comprehensive ophthalmic assessments, including OCT and OCT-A. We analyzed retinal parameters such as central macular thickness (CMT), Macular volume, Ganglion cell layer thickness, and retinal nerve fiber layer (RNFL) thickness, along with vessel density in the macular and peripapillary regions. Results GAD patients exhibited significantly lower CMT (243.30±21.15 μm vs. 268.79±17.34 μm, P=0.001), Macular volume (9.48±0.62 mm3 vs. 10.17±0.39 mm3, P=0.001), Ganglion cell layer thickness (83.60±78.24 μm vs. 92.30±74.73 μm, P=0.001), and total RNFL thickness (93.90±11.05 μm vs. 97.76±8.67 μm, P=0.001) compared with controls. RNFL thinning was noted in the nasal, inferior, and temporal regions. However, OCT-A revealed no significant differences in vessel density in the peripapillary and central macular areas between GAD patients and controls. Conclusion Patients with GAD exhibit significant retinal structural changes, particularly in the macular and RNFL regions. However, no significant differences in retinal vessel density were observed. These findings suggest that GAD may impact retinal morphology but not vascular density, indicating potential biomarkers for early detection and monitoring of GAD-related neurodegeneration.

Bio-spectroscopic investigation linking changes of retinal structure with short-term administration of Amiodarone and revealing the ameliorative effect of vitamin E supplementation

Long term use of Amiodarone (AMIO) is associated with the development of ocular adverse effects. This study investigates the short term effects, and the ameliorative consequence of vitamin E on retinal changes that were associated with administration of AMIO. This is accomplished by investigating both retinal structural and conformational characteristics using Fourier transform infrared spectroscopy (FTIR) and Fundus examination. Three groups of healthy rabbits of both sexes were used; the first group served as control. The second group was orally treated with AMIO (160 mg /kg body weight) in a daily basis for two weeks. The last group orally received AMIO as the second group for two weeks then, oral administration of vitamin E (100 mg/kg body weight) for another two weeks as well. FTIR results revealed significant structural and conformational changes in retinal tissue constituents that include lipids and proteins due to AMIO administration. AMIO treatment was associated with fluctuated changes (increased/decreased) in the band position and bandwidth of NH, OH, and CH bonds. This was concomitant with changes in the percentage of retinal protein constituents in particularly α-helix and Turns. AMIO facilitates the formation of intra-molecular hydrogen bonding and turned retinal lipids to be more disordered structure. In conclusion, the obtained FTIR data together with principal component analysis provide evidence that administration of vitamin E following the treatment with AMIO can ameliorate these retinal changes and, these biophysical changes are too early to be detected by Fundus examination.

Clinical study on the influence of phacoemulsification on retinal structure of senile cataract based on data mining.

With the improvement of the level of science and technology, diagnosis and treatment technology of ophthalmology has continuously improved, especially with the rise of optical coherence tomography. Alternative methods have enabled clinicians to obtain more information and make greater breakthroughs in the occurrence and development of many ophthalmic diseases. To investigate changes in retinal structure in the macular area of senile diabetic cataract patients undergoing cataract phacoemulsification. This was a prospective cohort study. A total of 68 cataract patients (78 eyes) who voluntarily received phacoemulsification combined with intraocular lens implantation in the Department of Ophthalmology of our hospital from December 2018 to December 2021 were selected. They were divided into A (diabetic) and B (non-diabetic) according to whether they were complicated with diabetes. There were 24 cases (28 eyes) in A and 44 cases (50 eyes) in B. Cataract patients were collected before and after surgery. Day, 1 week, and 1 month, data on the average thickness of the fovea retina and thickness of the retinal nerve fiber layer around the optic disc (average thickness, nasal thickness, topic side thickness, upper thickness, and lower thickness) were statistically analyzed analyze. The average retinal thickness of the macular fovea in Group A was found to be greater than that of Group B, however, there was no statistically significant difference between the two groups. At week one and week thirty, Group A's layer of retinal nerve fibers surrounding the optic disc thickened; there was no discernible difference between the two groups. One week and one month following surgery, however, showed a one-week difference in upper thickness compared to preoperative days. There was no discernible change between the preoperative and 1-day times. Both diabetic cataract patients and simple age-related cataract patients will have different degrees of increased foveal retinal thickness after surgery. However, the foveal retinal thickness of patients with diabetes increases more.

Impact of cumulative dose of hydroxychloroquine on retinal structures.

What is known • Hydroxychloroquine (HCQ) is widely used for autoimmune disorders but is associated with the risk of retinal toxicity. • Early detection of retinal structural changes due to HCQ toxicity remains challenging, and cumulative HCQ dose as a risk factor has conflicting clinical relevance. What Is New • Higher cumulative HCQ doses are significantly associated with thinner outer retinal layers (foveal, parafoveal, and perifoveal regions). • No significant associations were found between HCQ cumulative dose and inner retinal thickness or age.