Choroidal Thickness Research Articles

Choroidal thickness in macular, nasal midperiphery, and temporal midperiphery regions and its relationship with axial length and refractive error.

This study aimed to investigate the choroidal thickness (ChT) distribution in adult myopic eyes, focusing on the macular, nasal midperiphery, and temporal midperiphery regions, and to explore its relationship with axial length (AL) and refractive error. A cross-sectional, observational study. Twenty-nine eyes of 29 adult volunteers were examined. ChT was measured using high-speed swept-source optical coherence tomography covering an area of 50 degrees in three different regions: centered at macular, nasal side at 33 degrees, and temporal side at 33 degrees. Statistical analyses were performed to assess differences in ChT between regions and correlations with AL and spherical equivalent (SE). ChT was found to be thickest in the macular region, followed by the nasal and temporal midperiphery regions. Significant correlations were observed between AL/SE and ChT in the macular and temporal regions, but not in the nasal region. The temporal midperiphery showed the strongest correlation with AL and SE. This study revealed a nasal-temporal asymmetry in ChT distribution in myopic eyes, with the temporal midperiphery showing the thinnest ChT. The strong correlations between ChT in the temporal midperiphery and AL/SE suggest a role for the temporal choroid in axial elongation and myopia progression. These findings highlight the importance of considering peripheral ChT in understanding ocular growth and myopia management.

In vivo assessment of cone loss and macular perfusion in children with myopia

This study evaluated cone density (CD) in the macular region and assess macular perfusion in children with varying degrees of myopia. This was a prospective, cross-sectional, observational study. Children underwent confocal scanning laser ophthalmoscopy (cSLO), optical coherence tomography (OCT), and OCT angiography (OCTA) imaging. A built-in software was used to measure mean CD (cells/mm2), retinal vessel density, choriocapillaris perfusion area, and choroidal thickness (CT). The study included 140 eyes from children categorized into four groups: emmetropia (31 eyes), low myopia (44 eyes), moderate myopia (31 eyes), and high myopia (34 eyes). The high myopia group exhibited significantly lower macular CD than the emmetropia group (P < 0.05). Additionally, the high myopia group showed thinner CT and higher choriocapillaris perfusion area in the macular region than the emmetropia group (all P < 0.01). Macular CD was significantly correlated with age, spherical equivalent, axial length, and CT (all P < 0.05). Generalized linear models revealed CT as the independent factor associated with macular CD (Wald χ2 = 9.265, P = 0.002). Children with high myopia demonstrate reduced CD in the macular region, accompanied by reduced CT. These findings may have important implications for future myopia prevention and management strategies.

Optical Coherence Tomography Study of Choroidal Response to Exercise-Induced Hypertension in Chronic Central Serous Chorioretinopathy

Background/Objectives: The aim of this study was to evaluate the choroidal vascular response using optical coherence tomography (OCT) in patients with chronic central serous chorioretinopathy (CSCR) during transient increases in blood pressure. Methods: This observational, case–control study enrolled chronic CSCR patients and age-matched healthy controls. OCT scans of the macula were performed at rest and during hand-grip (HG) isometric exercise. Mean ocular perfusion pressure (MOPP) and subfoveal choroidal thickness (SCT) were measured at baseline and during stress. Quantitative OCT assessment included the bright area (BA, stroma), dark area (DA, vascular lumen), and total choroidal area (CA). The choroidal vascularity index (CVI) was calculated as DA/CA to assess vascular response to stress. A comparative analysis between CSCR patients and controls was conducted. Conclusions: MOPP was significantly higher (p = 0.008) at baseline in CSCR patients and further increased under stress compared to controls. SCT and CA were both significantly higher in CSCR patients than in healthy subjects at rest and under stress (p &lt; 0.001), but no change occurred after HG. A significant decrease in CVI (p = 0.005) was noted in controls under stress, but not in CSCR patients. Additionally, a negative correlation between CVI and MOPP was found in healthy subjects (−0.648; p = 0.043). The study demonstrated a choroidal vasoconstrictive response to stress in healthy subjects, as evidenced by a decrease in CVI, but not in CSCR patients. This suggests that CSCR patients may experience impaired choroidal blood flow regulation, resulting in potentially higher perfusion pressures during stress without compensatory vasoconstriction, potentially affecting the choriocapillaris.

How is the posterior ocular segment affected in cesarean section and normal vaginal delivery?

To evaluate the effects of normal vaginal delivery (NVD) and cesarean section (CS) on the retina, optic disc, and choroid in healthy pregnant women by using optical coherence tomography (OCT). This prospectively designed study included 60 healthy pregnant women, of whom 30 underwent NVD and 30 underwent CS. Ophthalmological examinations and OCT scans were performed on all pregnant women during the third trimester and the first postpartum week. The measurements were compared between the two visits within each group. Central retinal thickness, ganglion cell layer and inner plexiform layer (GCL + IPL) thickness, peripapillary retinal nerve fiber layer thickness, and optic disc morphology were determined using OCT scans. Central, nasal, and temporal choroidal thicknesses were manually measured using HD-line OCT. Choroidal vascular parameters were calculated from HD-line OCT scans by using a special image processing module. The ratio of the luminal choroidal area to the total choroidal area was determined as the choroidal vascular index (CVI). In the NVD group, the thinning in the mean and inferior pRNLF, the decrease in the rim area, and the increase in the mean cup/disc and cup volume at the first postpartum week were found to be statistically significant (P < 0.05). In the same group, the CVI was calculated as 0.69 ± 0.02 in the third trimester and 0.66 ± 0.03 in the first postpartum week (P = 0.001). In the CS group, except for the increase in the GCL + IPL thickness, no significant difference was detected in the measurements of the retina, optic disc, and choroid (P < 0.001 and P > 0.05). This is the first study to evaluate the effect of the delivery method on the retina, choroid, and optic disc. In NVD, changes in the choroidal vascular structure and optic disc morphology can be observed in the early postpartum period, which may be attributed to hormonal effects.

Periodontitis Provokes Retinal Neurodegenerative Effects of Metabolic Syndrome: A Cross-Sectional Study

Background: This cross-sectional study aims to investigate the retino-choroidal degenerative effects of periodontitis, metabolic syndrome (Mets), and the combination of these diseases using optical coherence tomography (OCT) measurements. Methods: Ninety-two patients selected according to inclusion criteria were divided into four groups: systemically and periodontally healthy (control), systemically healthy periodontitis (PD), periodontally healthy metabolic syndrome (MetS), and periodontitis and metabolic syndrome combined (PD-MetS). The systemic inflammatory–oxidative effects of periodontitis and MetS were biochemically evaluated using the serum TNF-α level, IL-1β/IL-10 ratio, and oxidative stress index (OSI: TOS/TAS). Retinal (AMT, pRNFLT, and GCL + T) and choroidal (SFCT) morphometric measurements and vascular evaluations (foveal capillary density) were performed via OCT Angio with swept-source technology. Results: Both periodontitis and Mets cause systemic inflammatory stress characterized by significant increases in the IL-1β/IL-10 ratio and OSI (p &lt; 0.05). Compared to the control group, the AMT was significantly thinner in the MetS group, the pRNFLT was significantly thinner in the PD-MetS group, and the SFCT was significantly thinner in both groups (p &lt; 0.05). The GCL+ was slightly thicker in the Mets groups. (p &gt; 0.05) Foveal capillary density did not differ significantly among the groups. (p &gt; 0.05). Conclusions: Periodontitis-related inflammatory stress alone causes changes in retinal and subfoveal choroidal thicknesses that are not statistically significant. On the other hand, when combined with Mets, it may significantly provoke the retinal neurodegenerative effects of this disease.

Macular Alterations in a Cohort of Caucasian Patients Affected by Retinitis Pigmentosa

Objectives: Our objective was to investigate the prevalence of macular complications detected by spectral-domain optical coherence tomography (SD-OCT) in a large Caucasian cohort of RP patients, highlight the major alterations in chorioretinal structure, and compare the macular structural changes in eyes affected by retinal dystrophies with those in healthy controls. Methods: This was an observational, retrospective, and cross-sectional study. Three hundred and seven patients with RP were consecutively enrolled and underwent clinical assessment. In particular, SD-OCT images were used to ascertain the morphology of the posterior pole of patients with RP by evaluating the residual ellipsoid zone (EZ), the volume and thickness of the outer nuclear layer (ONLT), and subfoveal choroid thickness (SCT). At the same time, the pathological finding that the patients’ vision was reduced under treatment was analyzed. Results: A total of 436 eyes of 218 patients with RP were studied. Considering all of the eyes studied, 103 had cystoid macular edema (CME) (23.62%), 123 (28.21%) had vitreomacular traction (VMT), and 199 (45.75%) had epiretinal membranes (ERMs). There were also 12 (2.75%) cases of lamellar macular holes (LMHs), of which 3 (1.38% of all patients) cases were bilateral. Only 137 eyes (31.42%) did not have the above-mentioned alterations. SCT was significantly reduced compared to that of the control group (193.03 µm ± 67.90 SD vs. 295 µm ± 69.04 SD), while the foveal central macular thickness (FCMT) was greater (270.91 μm ± 74.04 SD vs. 221 µm ± 37.25 SD). Conclusions: This research highlights the high incidence of macular complications. The results of our study indicate the importance of regular monitoring of RP patients and early intervention to avoid further complications in this group of subjects with severe visual field impairment to avoid further central vision loss.

Micropulse Laser versus Eplerenone for Chronic Central Serous Chorioretinopathy: A 12-Month Comparison.

To compare the long-term efficacy of navigated subthreshold micropulse laser (NSML) and continuous oral eplerenone (EPL) in chronic central serous chorioretinopathy (cCSC). This retrospective observational study included 44 eyes with cCSC (EPL: n = 26; NSML: n = 18). Best-corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF) height, and subfoveal choroidal thickness (SFCT) were evaluated over 12months. Both groups showed significant improvements in BCVA and CMT (p < 0.05). Complete SRF resolution was achieved in both groups by 12months, with NSML showing faster resolution (2.77 ± 1.43 vs. 6.34 ± 2.17months, p < 0.001). The EPL group demonstrated significant SFCT reduction at 6 and 12months (p = 0.001), while the NSML group showed no significant SFCT changes (p > 0.05). Both NSML and EPL improved retinal morphology and visual function in patients with cCSC. NSML achieved faster SRF resolution, while EPL resulted in more significant choroidal thickness reduction. These findings suggest distinct mechanisms of action: NSML primarily affects the retinal pigment epithelium, while EPL modulates choroidal vasculature. Treatment choice may depend on individual patient characteristics and treatment goals.

Comparison of subfoveal choroidal thickness in pre-eclamptic, healthy pregnant, and non-pregnant women.

The purpose of the study was to compare the choroidal thickness (CT) in pre-eclamptic (PE), healthy pregnant, and age-matched healthy non-pregnant females by spectral-domain optical coherence tomography (SD-OCT) and to investigate any possible correlation between subfoveal CT (SFCT) and mean arterial pressure (MAP) in PE. This was a hospital-based, comparative study. A total of 90 females (30 in each group) aged 20-40 years were recruited prospectively over 1 year. Females with refractive error beyond ±3 D, intraocular pressure >21 mmHg, prior ocular trauma or surgeries, systemic diseases, pregnancy-related complications (except PE), and poor OCT scans were excluded. Following comprehensive ophthalmic evaluation, CT was measured bilaterally using SD-OCT (EDI) at the subfoveal region and at 1500 μm nasal and temporal to fovea. Systolic and diastolic blood pressures were recorded in all. The PE group had significantly thinner choroid (SFCT: 337.5 ± 49.8 OD, 333.0 ± 50.8 OS) as compared to the healthy non-pregnant group (SFCT: 351.6 ± 34.4 OD, 365.3 ± 33.6 OS) and healthy pregnant group (SFCT: 374.2 ± 44.1 OD, 377.2 ± 49.5 OS) (P < 0.05) in all locations (nasal, temporal, and subfoveal) in both eyes (except for OD nasal CT). However, there was no significant correlation between SFCT and MAP in the PE group. Significantly lower CT in PE without any direct correlation between SFCT and MAP may implicate that choroidal thinning in PE is governed by multifactorial choroidal vasospasm and endothelial dysfunction, instead of MAP solely.

Caffeine and Vision: Effects on the Eye.

Caffeine, commonly found in coffee and tea, affects various aspects of eye health as it blocks adenosine receptors, impacting tear production, intraocular pressure, macular perfusion, and choroidal thickness. However, its connection with eye conditions like glaucoma and cataracts remains uncertain due to conflicting research findings. Some studies suggest potential benefits for cataracts, while others warn against frequent caffeine intake in glaucoma and surgical scenarios due to possible increases in intraocular pressure. Conflicting evidence also exists regarding its effects on dry eye, macular degeneration, myopia/hyperopia, diabetic retinopathy, retinopathy of prematurity, and central serous retinopathy. Caffeine does not seem to be a risk factor for dry eye, although studies have shown that caffeine may offer protection against wet age-related macular degeneration, and the metabolite 7-methylxanthine could be a more promising treatment for myopia. Moreover, caffeine can potentially cause tremors and might hinder surgical performance, especially in less experienced surgeons. Recommendations from experts vary, highlighting the need for further research to fully understand how caffeine affects the eye. Individuals genetically predisposed to glaucoma should be cautious due to the possibility of clinically significant elevations in intraocular pressure with caffeine consumption. For delicate procedures like microsurgery, where tremors can be detrimental, caution should be exercised with caffeine. This review underscores the importance of additional studies to provide clearer insights and prudent recommendations regarding caffeine's impact on eye health.

Distribution and associated factors of choroidal thickness in highly myopic eyes-a real-world study based on a Chinese population.

To measure the subfoveal choroidal thickness (SFCT) in highly myopic eyes at different locations using enhanced depth imaging spectral-domain optical coherence tomography (EDI SD-OCT). To identify the ocular and systemic risk factors associated with choroidal thinning in high myopia. Based on the Beijing Eye Study, a detailed ophthalmic examination was performed including EDI SD-OCT for the measurement of SFCT. OCT images were obtained from 103 highly myopic eyes (≥ -6.00 dioptres) and 227 normal eyes randomly selected from the baseline population, matched for age and sex. The mean SFCT was 110.6 ± 85.2 μm in highly myopic eyes (range, 3-395 μm). Mean regional choroidal thickness was lowest on the nasal and inferior sides of the macula, and slightly higher on the temporal and superior sides than at the fovea. On multivariate analysis, SFCT was associated with age (b = -0.48; P < 0.001), axial length (b = -0.44; P < 0.001), gender (b = -0.31; P < 0.05) and staphyloma (b = -0.26; P = 0.05). In highly myopic eyes, SFCT decreased by 5.1 μm/year of age, by 9.2 µm/D of myopia, and by 22.6 µm/mm of axial length. The SFCT decreases with age and increased axial length in highly myopic eyes. The formation of a posterior staphyloma has been identified as a major contributor to choroidal thinning and is therefore a reliable indicator for risk management. The involvement of choroidal abnormalities may be a significant factor in the development of myopic degeneration.

The effect of ocular dominance on choroidal structures

ABSTRACT This study aimed to compare the dominant and non-dominant eyes of healthy individuals in terms of CT and CVI values to assess the effect of ocular dominance on choroidal morphology. Three hundred eyes of 150 individuals were included in this study. All patients underwent routine ophthalmological examinations and hole-in-the-card tests to determine the dominant eye. EDI-OCT was used to obtain choroidal images. Choroidal thickness (CT) was measured at three points on the choroid including the subfoveal region (subfoveal choroidal thickness (SFCT)), 1500 μm nasal (NCT) and temporal (TCT) to the fovea. Choroidal vascularity index (CVI), total choroidal area (TCA), luminal area (LA), and stromal area (SA) were measured at fovea-centered choroidal area by image binarization via Image J software. While 93(%62) participants were right-eyed, 57(%38) participants were left-eyed. We could not detect any difference in SFCT, NCT, TCT, TCA, LA, SA, and CVI measurements between the dominant and the non-dominant eyes. (p > 0.05 for all). We could not detect any effect of ocular dominance on choroidal structures. These results also support the use of randomized ocular data regardless of which eye is dominant when investigating CVI and CT in scientific research.

Analysis of Choroidal Thickness Changes in Recurrent Rhegmatogenous Retinal Detachment.

To analyze changes in choroidal thickness in patients with recurrent rhegmatogenous retinal detachment (RRD) before and after surgical intervention and to identify factors that influence changes in choroidal thickness. A retrospective observational study was conducted on patients who underwent surgery for recurrent RRD from November 2019 to March 2023. Choroidal thickness was measured using optical coherence tomography (OCT) at baseline, and then at 2 and 6 months postoperatively. The study analyzed the impact of various factors on choroidal thickness changes. The study included 33 patients, demonstrating a significant decrease in choroidal thickness in the surgical eye compared to the fellow eye over a 6-month period. In the univariate analysis, changes in choroidal thickness were significantly correlated with changes in central retinal thickness (p=0.048) between 0-2 months, and with proliferative vitreoretinopathy (PVR) grade between 2-6 months (p=0.009) and 0-6 months(p=0.02). In the multivariate analysis, an association was found between changes in choroidal thickness from 2 to 6 months and PVR grade(p=0.030). The findings indicate that surgical reattachment in eyes with recurrent RRD leads to a significant reduction in choroidal thickness. The extent of this reduction is influenced by the severity of PVR, highlighting the importance of considering PVR severity when evaluating surgical outcomes in patients with recurrent RRD.

Evaluation of retinal nerve fiber layer and choroidal structure in obese children and adolescents

Aim: Obesity-related vascular damage and endothelial dysfunction have deleterious effects on the ocular vasculature. It was aimed to examine optical coherence tomography (OCT) parameters in obese and overweight children and to define their relationship with metabolic markers in this study. Methods: The patient group consisted of 26 obese, 24 overweight patients aged between 8 and 18 years. The control group consisted of 25 healthy children with normal body mass index (BMI). This was a cross-sectional observational study. Serum glucose, lipid parameters, and homeostasis model assessment of insulin resistance (HOMA-IR) were investigated. Measurement of choroidal thickness was performed with Cirrus HD-OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA). Retinal nerve fiber layer (RNFL) thickness was determined by an automatic computer algorithm without the need for user measurement. Results: There were no differences in subfoveal, nasal, temporal choroidal thickness, and RNFL between obese, overweight, and control groups (p&gt;0.05). A positive (linear) moderate relationship was found between RNFL and the HOMA-IR of 26 patients in the obese group (r=0.389) (p=0.049). A positively weak correlation was found between height and RNFL in obese patient group (r=0.264, p=0.028). Conclusion: In the study, RNFL thickness increased as HOMA-IR level increased in obese children and adolescents. RNFL decreased as the height increased in obese children and adolescents. We believe that more comprehensive data about the effect of obesity on RNFL and choroidal thickness will be obtained with prospective studies in which the obese patient group with insulin resistance is taken separately and disease durations are defined, and long-term patient follow-up is performed.

The Effect of Repeated Low-Level Red-Light Therapy on Myopia Control and Choroid.

To investigate the long-term effects of repeated low-level red light (RLRL) therapy on the axial length (AL), spherical equivalent (SE), and choroidal parameters. Two hundred eight myopic eyes were recruited. The RLRL group included 100 eyes, whereas the control group included 108 eyes. Throughout the one-year follow-up period, changes in AL and SE were recorded for both groups. The RLRL group underwent additional choroidal imaging, and changes in choroidal thickness (CT), choroidal vascularity (CV), and choriocapillaris luminal area (CLA) were assessed before and after RLRL therapy. During the follow-up period, the changing trends in AL and SE differed significantly between the RLRL and control groups. In the RLRL group, AL decreased at three and six months (both P < 0.05) and returned to pretreatment values at 12months (P = 0.453). In contrast, AL increased significantly throughout the follow-up period (three, six, and 12months) in the control group (all P < 0.001). The SE increased significantly during the entire follow-up period in the RLRL group (all P < 0.001), whereas it decreased significantly in the control group (all P < 0.05). Regarding choroidal parameters, significant improvements were observed in CT, CV and CLA throughout the follow-up period (all P < 0.05), and changes in most choroidal parameters were significantly correlated with changes in AL and SE during the follow-up period (all P < 0.05). Furthermore, AL, SE, and most choroidal parameters showed significant correlations between changes at three and 12months (all P < 0.05). RLRL therapy significantly improved choroidal blood perfusion and circulation, which may explain the observed slowing or reversal of myopia progression in the RLRL group. Thus RLRL therapy may be a novel and effective method for controlling myopia. Furthermore, the short-term effect of photobiomodulation therapy (i.e., changes at three months) can be used to predict the long-term effects (i.e., changes at 12months). In this study, RLRL therapy showed a significant control effect on the development of axial length and spherical equivalent. RLRL therapy also promoted the choroidal blood perfusion and circulation. RLRL therapy could be a novel and effective method for myopia control.

Visual and anatomical evaluation of navigated subthreshold micropulse laser versus photodynamic therapy in managing chronic central serous chorioretinopathy.

To compare the visual and anatomical results of navigated subthreshold micropulse laser (nSML) and photodynamic therapy (PDT) in the treatment of chronic central serous chorioretinopathy (CSCR). Patients who underwent either half-dose PDT or nSML for the management of chronic CSCR were included in this study. Comprehensive ophthalmic examination, fundus autofluorescence, and spectral domain optical coherence tomography (SD-OCT) were performed at baseline and at 1-, 3-, and 6-month follow-up visits after nSML or PDT. Fluorescein angiography and indocyanine green angiography were performed only at baseline. Main outcome measures were best corrected visual acuity (BCVA), central macular thickness (CMT), subretinal fluid (SRF), subfoveal choroidal thickness (SFCT), and choroidal vascularization index (CVI) that were collected at baseline and at each follow-up visit for up to 6 months. Forty-two eyes of 42 patients (PDT group-20 eyes, nSML group-22 eyes) affected by chronic CSCR were enrolled. At 6-month follow-up, no significant differences were observed between the nSML group compared to the PDT group in BCVA (0.10 [0.00; 0.20]) and 0.10 [0.10; 0.10], respectively, p=0.69, and between some OCT parameters, namely CMT and CVI. SFCT was significantly reduced in the PDT group more than in the nSML group (p=0.01). Twelve eyes (60%) in the PDT group had complete resolution of the SRF at 6 months compared to 8 eyes (36.4%) in the nSML group, but the difference was not statistically significant (p=0.14). Results from patients treated with PDT and nSML showed that, at 6 months, no significant differences except for choroidal thickness. nSML is less invasive than PDT and can be used as an effective alternative to PDT. WHAT IS KNOWN : Treating chronic CSCR is a therapeutic conundrum for clinicians because of a lack of definitive consensus over remediation options, two of which are photodynamic therapy (PDT) and navigated subthreshold micropulse laser (nSML) therapy. Results from patients treated with PDT and nSML showed no significant differences except for choroidal thickness. Even though patients treated with PDT recovered more quickly, retreatment was necessary due to fluid recollection. Although patients treated with nSML also needed retreatment, nSML is less invasive than PDT and can be used as an effective alternative to PDT.

The Macular Choroidal Thickness in Danish Children with Myopia After Two-Year Low-Dose Atropine and One-Year Wash-Out: A Placebo-Controlled, Randomized Clinical Trial.

Our aim in this work was to investigate the macular choroidal thickness (ChT) changes in 6-12-year-old Danish children with myopia during 2years of low-dose atropine treatment and 1-year wash-out vs. placebo in an investigator-initiated, placebo-controlled, double-blind randomized clinical trial. Ninety-seven participants wererandomized to either 0.01% for 2years, 0.1% loading dose for 6months followed by 0.01% for 18months, or placebo, then a 1-year wash-out. The primary outcome was ChT in the sub-foveal and inner and outer superior, nasal, inferior, and temporal sectors. The secondary outcome was axial length (AL). Outcomes were measured at baseline and 6, 12, 24, and 36 months. One-way analysis of variance was used to detect baseline ChT differences between AL-stratified groups (< 24mm, 24-25mm, or > 25mm). To determine the longitudinal changes in ChT and its effect on AL, all eyes were included in linear mixed modeling with individual eyes nested in the study ID as a random effect. Longer eyes had significantly thinner ChT in all choroidal sectors (adj-P < 0.01) at baseline. There was no statistically significant change in any ChT sector after 3years in the placebo group. Sub-foveal and nasal ChT in the 0.1% loading dose and 0.01% group were not significantly different from placebo after 2-year treatment. In the placebo group, a 1-mm increase in AL was significantly associated with a 47-µmthinner nasal ChT after 3years (95% confidence interval (CI): -55; -38, adj-P < 0.001). A 10-µmthicker nasal choroid at baseline was associated with 0.13 mm (95% CI: 0.009; 0.017, adj-P < 0.001) less 3-year axial elongation. The ChT in Danish children with myopia remained stable over the 3-year follow-up. A thinner choroid at myopia onset might predispose to increased axial elongation. Treatment with 0.01% atropine did not change the ChT. We speculate that low-dose atropine does not primarily reduce myopia progression via a choroidal mechanism. ClinicalTrials.gov identifier, NCT03911271.

Molecular mechanism of hypoxia and alpha-ketoglutaric acid on collagen expression in scleral fibroblasts.

To investigate the molecular mechanisms underlying the influence of hypoxia and alpha-ketoglutaric acid (α-KG) on scleral collagen expression. Meta-analysis and clinical statistics were used to prove the changes in choroidal thickness (ChT) during myopia. The establishment of a hypoxic myopia model (HYP) for rabbit scleral fibroblasts through hypoxic culture and the effects of hypoxia and α-KG on collagen expression were demonstrated by Sirius red staining. Transcriptome analysis was used to verify the genes and pathways that hypoxia and α-KG affect collagen expression. Finally, real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used for reverse verification. Meta-analysis results aligned with clinical statistics, revealing a thinning of ChT, leading to scleral hypoxia. Sirius red staining indicated lower collagen expression in the HYP group and higher collagen expression in the HYP+α-KG group, showed that hypoxia reduced collagen expression in scleral fibroblasts, while α-KG can elevated collagen expression under HYP conditions. Transcriptome analysis unveiled the related genes and signaling pathways of hypoxia and α-KG affect scleral collagen expression and the results were verified by RT-qPCR. The potential molecular mechanisms through which hypoxia and α-KG influencing myopia is unraveled and three novel genes TLCD4, TBC1D4, and EPHX3 are identified. These findings provide a new perspective on the prevention and treatment of myopia via regulating collagen expression.

Automatic fovea detection and choroid segmentation for choroidal thickness assessment in optical coherence tomography.

To develop an automated model for subfoveal choroidal thickness (SFCT) detection in optical coherence tomography (OCT) images, addressing manual fovea location and choroidal contour challenges. Two procedures were proposed: defining the fovea and segmenting the choroid. Fovea localization from B-scan OCT image sequence with three-dimensional reconstruction (LocBscan-3D) predicted fovea location using central foveal depression features, and fovea localization from two-dimensional en-face OCT (LocEN-2D) used a mask region-based convolutional neural network (Mask R-CNN) model for optic disc detection, and determined the fovea location based on optic disc relative position. Choroid segmentation also employed Mask R-CNN. For 53 eyes in 28 healthy subjects, LocBscan-3D's mean difference between manual and predicted fovea locations was 170.0 µm, LocEN-2D yielded 675.9 µm. LocEN-2D performed better in non-high myopia group (P=0.02). SFCT measurements from Mask R-CNN aligned with manual values. Our models accurately predict SFCT in OCT images. LocBscan-3D excels in precise fovea localization even with high myopia. LocEN-2D shows high detection rates but lower accuracy especially in the high myopia group. Combining both models offers a robust SFCT assessment approach, promising efficiency and accuracy for large-scale studies and clinical use.

Short-Term Effect of Stimulating the Pterygopalatine Ganglion Via Electroacupuncture on Choroidal Structure in Human Subjects.

Choroidal dysfunction is implicated in various ocular pathologies. The parasympathetic pterygopalatine ganglion (PPG) innervates orbital vessels supplying the choroid. While PPG stimulation has been shown to dilate cerebral blood flow, its effects on the choroid, particularly in human subjects, require further elucidation. This study aimed to investigate the short-term influence of PPG stimulation via electroacupuncture on choroidal structure. In this crossover study, 22 healthy adults received PPG electrical stimulation and sham stimulation for one session each on two separate days in a randomized order. Measurements including choroidal thickness (ChT), choroidal vascularity index (ChVI), central subfield thickness, axial length, anterior chamber depth, and lens thickness were recorded before and at intervals (0, 15, 30, 45, and 60minutes) postintervention. The ChT on the side receiving PPG stimulation demonstrated a sustained increase, peaking at 15minutes poststimulation (17.2µm, P < 0.001) and persisting for up to 60minutes. Conversely, the ChVI exhibited a more immediate response, with a peak increase immediately poststimulation (3.8%, P = 0.003), followed by a gradual return to baseline. ChT and ChVI in the contralateral eye showed a nonsignificant trend to decrease. Additionally, a notable reduction in ipsilateral axial length was observed at specific time points poststimulation. PPG activation via electroacupuncture elicited a short-term increase in ChT and ChVI in the ipsilateral eye compared to sham stimulation, with ChT increases trailing those of ChVI but displaying greater persistence. Electrical stimulation of the PPG can produce a short-term increase in ipsilateral ChT and ChVI.

An investigation on choroidal and retinal thickness alterations in Posner-Schlossman syndrome patients

BackgroundWe aimed to compare choroidal thickness (ChT) and retinal nerve fiber layer (RNFL) thickness in the affected and contralateral eyes of patients with Posner-Schlossman Syndrome (PSS) during acute, remission, and intermittent phases.MethodsThis prospective observational study included 18 patients(36 eyes) diagnosed with PSS. These patients underwent a comprehensive ophthalmologic evaluation including slit lamp examination, visual acuity testing, intraocular pressure (IOP) measurement, and funduscopic examination, and assessment of RNFL thickness, macular thickness, and macular ChT. Patient data collected included gender, age, number of keratic precipitates (KPs), and number of episodes. Optical coherence tomography (OCT) was used to measure RNFL thickness, macular thickness, and macular ChT in both eyes during the acute, remission, and intermittent phases. The affected eye was compared with the unaffected eye at each phase.ResultsIn affected eyes, macular ChT was lower in the acute phase compared to the remission phase at N1500, N1000, N500, and subfoveal locations (allp < 0.05).The central macular recess ChT was also significantly thinner in the acute phase compared to the intermittent and remission phases. Age significantly correlated with ChT in the central recess (p = .024). Macular thickness was thinner during the acute phase in the affected eye (p = .048). The RNFL in the affected eye was thinner in the intermittent phase than in the acute phase at the inferior-temporal (p = .011) and global sectors (p = .044). During the acute phase, RNFL in the affected eye was thinner at the superior-nasal (p = .049), inferior-temporal (p = .003), and global (p = .041) sectors compared to the unaffected eye. In the intermittent phase, the affected eye’s RNFL was thinner at the superior-nasal, inferior-temporal, inferior-nasal, and global sectors compared to the unaffected eye (allp < 0.05), while no difference was observed in both eyes at the nasal, superior-temporal, and temporal sectors. The number of episodes and age were significantly associated with RNFL thickness (p < .05).ConclusionThis study demonstrated that in eyes affected by PSS, RNFL, macular ChT, and macular thickness thinned during the acute phase. The number of episodes and age are significant factors in the development of PSS.