Changes In Choroidal Thickness Research Articles

Comment on: Evaluation of retinal and choroidal thickness changes in overweight and obese adults without ocular symptoms by swept-source optical coherence tomography

Comment on: Evaluation of retinal and choroidal thickness changes in overweight and obese adults without ocular symptoms by swept-source optical coherence tomography

Changes in choroidal thickness quantified by Optical Coherence Tomography across cognitive impairment: data from the NORFACE cohort.

Optical coherence tomography (OCT) enables high-resolution imaging of ocular structures in health and disease. Choroid thickness (CT) is a key vascular retinal parameter that can be assessed by OCT and might be relevant in the evaluation of the vascular component of cognitive decline. We aimed to investigate CT changes in a large cohort of individuals cognitive unimpaired (CU), with mild cognitive impairment due to Alzheimer's (MCI-AD), mild cognitive impairment due to cerebrovascular disease (MCI-Va), Alzheimer's disease dementia (ADD), and vascular dementia (VaD). Clinical, demographical, ophthalmological and OCT data from the Neuro-ophthalmological Research at Fundació ACE (NORFACE) project were analyzed. CT was assessed in the macula across nine Early Treatment Diabetic Retinopathy Study (ETDRS) quadrants, average thickness, total volume, and subfoveal choroidal thickness. Differences of CT among the five diagnostic groups were assessed in a multivariate regression model, adjusting for demographic and cardiovascular risk factors and OCT image quality. A comparison between manual and automatic CT measurements in a subset of participants was also performed. The study cohort comprised 1,280 participants: 301 CU, 196 MCI-AD, 112 MCI-Va, 578 ADD, and 93 VaD. CT was significantly increased in individuals with cognitive impairment compared to those CU, particularly in the VaD and MCI-Va groups and in the peripheral ETDRS regions. No significant differences were found in inner superior, center and subfoveal choroidal thickness. The interaction of sex and diagnosis had no effect in differentiating CT. Mini-Mental State Examination (MMSE) scores were not correlated to CT. Manual and automated CT measurements showed good reliability. Our findings indicated that peripheral choroidal thickening, especially in patients with cerebrovascular disease, may serve as a potential choroidal biomarker for cognitive decline and suggest different pathogenic pathways in AD and VaD. Further research is required to explore CT as a reliable ocular biomarker for cognitive impairment.

Changes in choroidal thickness and lamina cribrosa position in subjects with overdipper pattern of arterial pressure.

The purpose is to analyze the changes produced in subjects with an overdipper pattern of ambulatory blood pressure monitoring with the aim of understanding the pathophysiology of normal tension glaucoma. A cross sectional study was performed in patients exhibiting overdipper and non-overdipper blood pressure patterns, respectively. Different optic parameters were assessed including the analysis of ganglion cell layer (GCL), peripapillary retinal nerve fiber layer (pRNFL) and Bruch's membrane opening-minimum rim width (BMO-MRW), as well as changes produced in choroidal thickness (CT) and lamina cribrosa (LC) position at two different periods of the day (early morning and evening). A total of 80 eyes (42 overdipper and 38 non-overdipper) were analyzed. A shortening of the distance at the beginning and end of the LC was objectified in the overdipper subjects (p < 0.003) as well as a statistically significant shift of the LC between morning and evening measurements in the overdipper subjects (p < 0.023). In addition, a significant thickening was found in 13 measurements of the horizontal and vertical plane CT (p < 0.029) of the overdipper subjects and a thickening of the CT in both groups in the morning. No significant differences in pRNFL, BMO-MRW and GCL measures were objectified. Morning assessment in overdipper subjects showed a deeper LC and a LC shift in comparison to evening values. In addition, an increase in CT was found in these subjects. Altogether, these findings could illustrate an etiopathogenic mechanism of the damage produced in normal tension glaucoma associated to the overdipper pattern.

Association of hypertension defined by the 2017 ACC/AHA guideline and choroidal thickness changes in type 2 diabetes: a 2-year longitudinal study.

This prospective cohort study investigated the longitudinal relationship between hypertension (HTN), defined by the 2017 ACC/AHA guidelines, and changes in choroidal thickness (CT) in patients with type 2 diabetes. Patients aged 30-80 years from the Guangzhou Diabetic Eye Study were categorized into non-HTN, stage 1-HTN, and stage 2-HTN groups based on BP criteria. Macular and parapapillary CT were measured using swept-source optical coherence tomography (SS-OCT). Mixed linear regression models analysed CT decline rates over a median 2.1-year follow-up, adjusting for confounders. 803 diabetes patients were included. Both stage 1-HTN and stage 2-HTN groups showed significantly thinner macular and parapapillary CT compared to non-HTN (all P < 0.05). Stage 2-HTN correlated with reduced macular CT thinning (coef = -11.29 μm/year; 95% CI, -22.36 to -0.22; P = 0.046) after adjustment, but not in the parapapillary area (coef = -4.07 μm/year; 95% CI, -12.89 to 4.74; P = 0.365). Subgroup analyses indicated faster macular CT decline in stage 2-HTN among those <65 years old (coef = -20.31 μm/year; 95% CI, -35.67 to -4.95; P = 0.10), males (coef = -14.1 μm/year; 95% CI, -32.54 to -4.33; P = 0.004), BMI ≥ 25 kg/m2 (coef = -10.24 μm/year; 95% CI, -26.86 to -6.38; P = 0.007), HbA1c > 6.5% (coef = -8.91 μm/year; 95% CI, -13.49 to -4.68; P = 0.001), and diabetes duration <10 years (coef = -12.78 μm/year; 95% CI, -27.48 to -1.91; P = 0.008). Stage 2-HTN is associated with accelerated macular CT loss in diabetic patients, suggesting macular CT measurements could potentially serve as early indicators of systemic hypertension. Further research is needed to establish precise CT cutoff values for clinical use in detecting and monitoring hypertension-related ocular changes.

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.

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.

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.

Dynamic BMP gene expression regulation in chick RPE during recovery from short term optical defocus and form-deprivation.

This study investigated the differential gene expression of BMPs in chick retinal pigment epithelium (RPE) during recovery from short term exposure to optical defocus and form-deprivation (FD) treatments. 14-day old White-Leghorn chicks wore either monocular +10 or -10 D lenses, or diffusers for 2 or 48 h, after which eyes were allowed unobstructed vision for up to 96 h. Over this recovery period, refractive errors and choroidal thickness (ChT) were tracked using retinoscopy and high-frequency A-scan ultrasonography. Real-time PCR was used to examine the expression of BMP2, 4, and 7 genes in RPE samples collected 0, 15 min, 2, 24, 48, and 96 h after the termination of treatments. Expression levels in treated eyes and their contralateral control eyes were compared. After the termination of the lens and diffuser treatments, eyes gradually recovered from induced shifts in refractive error. With all three treatments, ChT changes reached statistical significance after 48 h of treatment, be it thinning with the -10 D lens and diffuser treatments (-0.06 ± 0.03mm, p < 0.05; -0.11 ± 0.04 mm, p < 0.05, resp.), or thickening with the +10 D lens (0.31 ± 0.04 mm, p < 0.001). BMP2 gene expression was rapidly upregulated in eyes wearing the +10 D lens, being statistical significance after 2 h, as well as 48 h of treatment. With the 2 h treatment, the latter gene expression pattern persisted for 15 min into the recovery period, before decreasing to the same level as that of contralateral control eyes, with a short-lived rebound, i.e., upregulation, 24 h into the recovery period. With the longer, 48 h treatment, BMP2 gene expression decreased more gradually, from 739 ± 121% at the end of the treatment period, to 72 ± 14% after 48 h of recovery. Two and 48 h of both -10 D and FD treatments resulted in BMP2 gene expression downregulation, with the time taken for gene expression levels to fully recover varying with the duration of initial treatments. In both cases, BMP2 gene expression downregulation persisted for 15 min into the recovery period, but reversed to upregulation by 2 h. Similar gene expression patterns were also observed for BMP4, although the changes were smaller. The observed changes in BMP gene expression in chick RPE imply dynamic, albeit complex regulation, with the duration of exposure and recovery being critical variables for all three types of visual manipulations. This study provides further evidence for a role of the RPE as an important signal relay linking the retina to the choroid and sclera in eye growth regulation.

Changes in choroidal thickness and blood flow in response to form deprivation-induced myopia and repeated low-level red-light therapy in Guinea pigs.

To evaluate ocular refractive development, choroidal thickness (ChT) and changes in choroidal blood flow in form-deprived myopia (FDM) Guinea pigs treated with repeated low-level red-light (RLRL) therapy. Twenty-eight 3-week-old male tricolour Guinea pigs were randomised into three groups: normal controls (NC, n = 10), form-deprived (FD, n = 10) and red light treated with form-deprivation (RLFD, n = 8). Interocular refraction and axial length (AL) changes were monitored. Optical coherence tomography angiography (OCTA) measured choroidal thickness, vessel area density, vessel skeleton density and blood flow signal intensity (flux) in the choriocapillaris and medium-large vessel layers. The experimental intervention lasted 3 weeks. At week 3, the FD group had higher myopia and longer axial length than the NC group (all p < 0.001). The RLFD group had higher hyperopia and shorter axial length than the FD group (all p < 0.001). At week 1, the NC group had a thicker choroidal thickness than the FD group (p < 0.05). At weeks 2 and 3, the RLFD group had a thicker choroidal thickness than the FD group (p = 0.002, p < 0.001, respectively). Additionally, the NC group had higher vessel area density, vessel skeleton density and flux in the choriocapillaris layer than the FD group at the three follow-up time points (all p < 0.05). At week 3, the vessel skeleton density and flux were higher in the RLFD group than in the FD group (all p < 0.05). Correlation analysis results showed that weekly changes in refraction and choroidal thickness were negatively correlated with changes in axial length (all p < 0.05). Choroidal thickness changes were positively correlated with alterations in the vessel area density, vessel skeleton density and flux in the choriocapillaris layer, as well as vessel skeleton density and flux changes in the medium-large vessel layers (all p < 0.05). Repeated low-level red-light (RLRL) therapy retards FDM progression in Guinea pigs, potentially through increased choroidal blood flow in the choriocapillaris layer.

Lifelong Changes in the Choroidal Thickness, Refractive Status, and Ocular Dimensions in C57BL/6J Mouse.

To investigate the changes in choroidal thickness (ChT), refractive status, and ocular dimensions in the mouse eye in vivo using updated techniques and instrumentation. High-resolution swept-source optical coherence tomography (SS-OCT), eccentric infrared photoretinoscopy, and custom real-time optical coherence tomography were used to analyze choroidal changes, refractive changes and ocular growth in C57BL/6J mice from postnatal day (P) 21 to month 22. The ChT gradually increased with age, with the thickest region in the para-optic nerve head and thinning outward, and the temporal ChT was globally thicker than the nasal ChT. Retinal thickness remained stable until 4months and subsequently decreased. The average spherical equivalent refraction error was -4.81 ± 2.71 diopters (D) at P21, which developed into emmetropia by P32, reached a hyperopic peak (+5.75±1.38D) at P82 and returned to +0.66 ± 1.86 D at 22months. Central corneal thickness, anterior chamber depth, lens thickness, and axial length (AL) increased continuously before 4months, but subsequently exhibited subtle changes. Vitreous chamber depth decreased with lens growth. ChT was correlated significantly with the ocular parameters (except for retinal thickness) before the age of 4months, but these correlations diminished after 4months. Furthermore, for mice younger than 4months, the difference in the ChT, especially temporal ChT, between the two eyes contributed most to that of axial length and spherical equivalent refraction error. Four months could be a watershed age in the growth of mouse eyes. Large-span temporal recordings of refraction, ocular dimensions, and choroidal changes provided references for the study of the physiological and pathological mechanisms responsible for myopia.

Axial Shortening Effects of Repeated Low-level Red-light Therapy in Children with High Myopia: A Multicenter Randomized Controlled Trial

PurposeTo evaluate the effectiveness and safety of RLRL in delaying the progression of high myopes -6.00 D or worse. DesignMulticenter, randomized, parallel-group, single-blind clinical trial. ParticipantsTwo hundred and two high myopic children aged 7 to 12 years with cycloplegia spherical equivalent refraction (SE) ≤ -6.00 D, astigmatism less than 2.50 D, anisometropia of 1.50 D or less were enrolled from March 2022 to December 2022. Follow-up was completed in December 2023. MethodsEligible participants were randomly allocated to either the intervention (RLRL + single vision spectacle [SVS]) or the control group (SVS). The RLRL treatment was administered every day for 3 minutes, twice a day, with an interval of at least 4 hours. Main Outcomes MeasuresThe primary outcome was the change in axial length (AL) at 12 months compared to baseline. Secondary outcomes included changes in SE, changes of choroidal thickness (ChT) and retinal thickness (RT) in different circle sectors. Outcomes were analyzed by means of intention-to-treat and per-protocol methods. ResultsAfter 12-month treatment, AL and SE changes were -0.11 ± 0.25 mm and 0.18 ± 0.63 D for RLRL group and 0.32 ± 0.09 mm and -0.80 ± 0.42 D for control group. Axial shortening > 0.05 mm was observed to 59% in the RLRL and 0% in the control group at 12 months. ChT and RT from a single center were analyzed. In the RLRL group, ChT were thickened in all sectors at 12 months. RT was increased in parafoveal and perifoveal circles. In the control group, all sectors of ChT and only perifoveal RT were significantly thinner at 12 months. The multivariate linear regression model revealed significant correlations between changes in ChT central foveal circle and RT perifoveal circle at 1 month and AL changes at 12 months. No fundus structure changes, afterimage exceeding 6 minutes nor best corrected visual acuity decreased reported. ConclusionsRLRL could effectively shorten the AL and inhibit the progression of myopia in high myopic patients -6.00 D or worse. AL shortening is sustained over 12 months of treatment. These observed changes appeared to be associated with increases in ChT and RT.

Choroidal Thickening Induced by Pioglitazone in Diabetic Patients.

This study aimed to determine the changes in choroidal thickness induced by pioglitazone in diabetic patients. A total of 261 patients diagnosed with type 2 diabetes who had taken oral pioglitazone for more than 6 months were included in the study. After excluding patients who did not undergo regular eye examinations or who had ophthalmic surgery/interventions during the treatment period, a total of 40 eyes were included. The study examined the duration and dosage of pioglitazone, patient age, ocular axial length, refraction, glycated hemoglobin, systolic blood pressure, corrected visual acuity, macular thickness, choroidal thickness, and choroidal vascular index. Patients were categorized into a high-dose group if their pioglitazone dose was 30 mg or more per day, and a low-dose group if it was 15 mg or less. Choroidal thickness was measured below the subfovea and a 500 µm radius nasal and temporal to that location. Choroidal thickness significantly increased after 6 and 12 months of pioglitazone (6.70 and 13.65 µm, respectively) in all subjects. When stratified by pioglitazone dosage, choroidal thickness increased at 6 and 12 months in both high-dose group (4.48 and 0.84 µm, respectively) and low-dose groups (6.85 and 21.45 µm, respectively), with a greater change observed in the low-dose group (p < 0.05). Based on the location of choroidal thickness measurements, a significant increase in choroidal thickness was observed at 6 and 12 months of pioglitazone treatment in the subfoveal (7.00 and 13.15 µm, respectively) and nasal regions (6.43 and 19.24 µm, respectively), while a significant increase was only observed after 6 months of treatment in the temporal region (8.53 µm, p < 0.05). The largest increase in choroidal thickness was observed in the nasal side. This study found that choroidal thickness increased in diabetic patients after taking pioglitazone. Regular eye examinations are recommended for diabetic patients who are on pioglitazone.

The effect of travoprost on subfoveal choroidal thickness in primary open angle glaucoma

Toassess the effect of topical travoprost on subfoveal Choroidal Thickness in Primary open glaucoma patients. The choroidal thickness, a sign of ocular blood flow can be altered by prostaglandin analogues. Hence this study was done to analyse the choroidal thickness after travoprost therapy.: This Prospective, interventional study included 41 eyes of treatment naive POAG patients. Subfoveal choroidal thickness was measured at first visit and after 3 months of topical travoprost therapy by Enhanced Depth Imaging Optical Coherence Tomography (EDI-OCT). The measurements were compared before starting the treatment and after 3 months of treatment with travoprost therapy. The mean choroidal thickness pre-treatment was 296.73 ± 28.07 mm post treatment was 311.56 ± 33.38 µm. The mean difference in choroidal thickness between pre-treatment and post-treatment was found to be 14.8 ±15.1 µm with median value(IQR) of 8 (3 - 30) µm (p-value&amp;#60; 0.00) which was statistically significant.Thecurrent study showed that Subfoveal choroidal thickness(SFCT) changes with travoprost therapy.

Axial length reduction and choroidal thickening with short-term exposure to cyan light in human subjects.

Given the potential role of light and its wavelength on ocular growth, this study investigated the effect of short-term exposure to red, cyan and blue light on ocular biometry in humans. Forty-four young adults and 20 children, comprising emmetropes and myopes, underwent 2-h sessions of cyan (507 nm), red (638 nm) and broadband white light on three separate days via light-emitting glasses. Additionally, young adults were exposed to blue light (454 nm) on an additional day. Axial length (AL) and choroidal thickness (CT) were measured in the right eye before the light exposure (0 min), after 60 and 120 min of exposure and 30 min after light offset using an optical biometer and optical coherence tomographer, respectively. Compared to broadband light, exposure to red light resulted in a significant increase in AL (mean difference between white and red light at 120 min, +0.007 mm [0.002]), but no significant change in CT, while cyan light caused a significant AL reduction (-0.010 mm [0.003]) and choroidal thickening (+0.008 mm [0.002]) in young adults (p < 0.05). Blue light caused a significant decrease of -0.007 mm (0.002) in young adult eyes at 60 min (p < 0.05). In children, cyan light led to a significant reduction in AL (-0.016 mm [0.004]) and strong sustained choroidal thickening (+0.014 mm [0.004]) compared to broadband light at 120 min (p < 0.05). The effects of cyan light on AL and CT were found to be stronger in myopic young adults and emmetropic children. The opposing effects of red and cyan light on ocular biometry were similar between the two age groups (p > 0.05). Exposure to cyan light resulted in AL reduction and choroidal thickening in both young adults and children. Further research is needed to determine the application of these results in developing interventions for myopia control.

VEGFA may be a potential marker of myopic choroidal thickness and vascular density changes

To evaluate the changes of choroidal thickness (CT) and blood flow related to myopia, and its effects of vascular endothelial growth factor (VEGFA) on choroidal vessels in myopia. Subjects were included and divided into emmetropia (EM), non-high myopia (Non-HM) and high myopia (HM) groups. we measured choroidal thickness (CT), choriocapillaris vessel density (VD), and VEGFA content in tears in humans (137 subjects for CT, VD and 84 for tear) and detected the role of VEGFA in the choroid in form-deprivation myopia (FDM) in guinea pigs. Twenty-four guinea pigs were divided into control and FDM groups, and the expression changes of choroidal vessels and VEGFA were observed and compared using immunohistochemistry and Western blotting. Twenty-one guinea pigs were divided into control, FDM + Vehicle and FDM + Conbercept groups. The changes of diopter, axis length and choroidal vessels after intravitreal injection of Conbercept were observed. There were significant differences in CT and VD among the three groups (p < 0.05). VEGFA levels in tears were significantly lower in the myopic groups, with a decreasing trend from EM to Non-HM to HM. The choroidal vascular area fraction of FDM decreased compared to the control group. FDM guinea pigs exhibited reduced choroidal vasculature and significant downregulation of VEGFA expression. Following intravitreal injection of conbercept, the FDM + Conbercept group showed greater myopia, longer axial length, and lower choroidal vascular area fraction compared to the control group. VEGFA may participate in the regulation of choroidal blood vessels and blood flow in the progression of myopia. The reduction in VEGFA may accelerates the progression of myopia.

Retinal and Choroidal Phenotypes Across Novel Subtypes of Type 2 Diabetes Mellitus

PurposeThis study aimed to investigate longitudinal changes in choroidal thickness (CT) and ganglion cell-inner plexiform layer thickness (GC-IPLT) across distinct phenotypes of type 2 diabetes mellitus (T2DM) patients. DesignProspective observational cohort study. MethodsT2DM patients were categorized into five groups (SAID, SIDD, SIRD, MOD, and MARD) using K-means clustering based on β-cell function and insulin resistance. Swept-source optical coherence tomography measured baseline and 4-year follow-up CT and GC-IPLT. Linear mixed-effects models assessed absolute and relative changes in CT and GC-IPLT across subtypes. ResultsOver a median 4.11-year follow-up, CT and GC-IPLT decreased significantly across all groups. Choroidal thinning rates were most pronounced in SIDD (-6.5±0.53 µm/year and -3.5±0.24%/year) and SAID (-6.27±0.8 µm/year and -3.19±0.37%/year), while MARD showed the slowest thinning (-3.63±0.34 µm/year and -1.98±0.25%/year). SIRD exhibited the greatest GC-IPLT loss (-0.66±0.05 µm/year and -0.91±0.07%/year), with the least in SIDD (-0.36±0.05 µm/year and -0.49±0.07%/year), all statistically significant (Ps < 0.001). Adjusted for variables, SIDD and SAID groups showed faster CT thinning than MARD [-2.57 µm/year (95% CI: -4.16 to -0.97; P=0.002) and -2.89 µm/year (95% CI: -4.12 to -1.66; P<0.001), respectively]. GC-IPLT thinning was notably accelerated in SIRD versus MARD, but slowed in SIDD relative to MARD [differences of -0.16 µm/year (95% CI: -0.3 to -0.03; P=0.015) and 0.15 µm/year (95% CI: 0.03 to 0.27; P=0.015), respectively]. Stratified analysis revealed significant differences among non-DR groups. ConclusionsMicrovascular damage in the choroid is associated with SIDD patients, whereas early signs of retinal neurodegeneration are evident in SIRD patients. All these changes may precede the onset of DR.

Light Therapy for Myopia Prevention and Control: A Systematic Review on Effectiveness, Safety, and Implementation.

This systematic review focuses on the effectiveness, safety, and implementation outcomes of light therapy as an intervention to prevent or control myopia in children. A systematic literature search was performed in PubMed, EMBASE, CINAHL, SCOPUS, and Web of Science up to January 27, 2024. Effectiveness outcomes included myopia incidence, and changes in axial length (AL), spherical equivalent refraction (SER), and choroidal thickness (CT). Safety outcomes relating to retinal health or damage and implementation outcomes including compliance rates and loss to follow-up were extracted. ROBINS-I, ROB 2, and ROB-2 CRT were used to assess risk of bias. Nineteen interventional studies were included. Increased outdoor time (n = 3), red-light therapy (n = 13), and increased classroom lighting (n = 1) had a significant effect on myopia incidence, and changes in AL, SER, and CT. Violet-light therapy (n = 2) was only effective in children aged 8 to 10 years and children without eyeglasses with less than 180minutes of near-work time daily. Two studies using red-light therapy reported adverse effects. For all studies, only compliance rates and loss to follow-up were reported on implementation effectiveness. Evidence is compelling for the effectiveness of red-light therapy and outdoors time; more data are needed to confirm safety. Robust data are still needed to prove the effectiveness of violet-light and increased classroom lighting. Clearer implementation strategies are needed for all light therapies. Light therapy has emerged as effective for myopia prevention and control. This systematic review summarizes the state of knowledge and highlights gaps in safety and implementation for these strategies.

Evaluation of Choroidal Thickness and Retinal Vessel Density with Serum HIF-1α and TNF-α Level in Patients with OSAS

Purpose To reveal changes in choroidal thickness, retinal vessel density, and serum HIF-1α and TNF-α levels in obstructive sleep apnea syndrome (OSAS) and their correlation. Methods This prospective case-control study included 118 patients divided into mild-to-moderate OSAS (n = 40), severe OSAS (n = 39), and a control group (n = 39). Choroidal thickness was evaluated with OCT, vessel density with OCTA, AHI index with polysomnography, and serum HIF-1α and TNF-α levels were analyzed using the enzyme-linked immunosorbent assay. Results The serum HIF-1α values of the participants in the mild-moderate OSAS and severe OSAS groups were [893.25(406.7–2068) and 1027(453–2527), respectively], and were both significantly higher than the control group [(521.5(231.6–2741))] (p < 0.001). Serum TNF-α levels did not differ significantly between the groups (p = 0.051).). Subfoveal choroidal thickness (SFCT) values of the severe OSAS groups were significantly lower than the control group (p < 0.05). The superficial and deep capillary plexus vascular density (SVD and DVD) values of the severe OSAS group were lower than the control group (p < 0.05). Serum HIF-1α and TNF-α levels of all participants were negatively correlated with both their SVD values (p < 0.05, r: –0.220 and p < 0.05, r: –0.252, respectively) and their DVD values (p < 0.001, r: –0.324 and p = 0.001, r: –0.299, respectively). Conclusions Increased serum levels of inflammatory mediators (HIF-1α ve TNF-α) in OSAS cause a decrease in SFCT, SVD, and DVD, which is an indication of systemic vascular damage. Further research on developing treatment strategies to modulate TNF-α ve HIF-1α may help recede vascular morbidity in OSAS patients.

Choroidal Changes During and After Discontinuing Long-Term 0.01% Atropine Treatment for Myopia Control.

Few studies have explored choroidal changes after cessation of myopia control. This study evaluated the choroidal thickness (ChT) and choroidal vascularity index (CVI) during and after discontinuing long-term low-concentration atropine eye drops use for myopia control. Children with progressive myopia (6-16years; n = 153) were randomized to receive 0.01% atropine eye drops or a placebo (2:1 ratio) instilled daily over 2years, followed by a 1-year washout (no eye drop use). Optical coherence tomography imaging of the choroid was conducted at the baseline, 2-year (end of treatment phase), and 3-year (end of washout phase) visits. The main outcome measure was the subfoveal ChT. Secondary measures include the CVI. During the treatment phase, the subfoveal choroids in both treatment and control groups thickened by 12-14 µm (group difference P = 0.56). During the washout phase, the subfoveal choroids in the placebo group continued to thicken by 6.6 µm (95% confidence interval [CI] = 1.7 to 11.6), but those in the atropine group did not change (estimate = -0.04 µm; 95% CI = -3.2 to 3.1). Participants with good axial eye growth control had greater choroidal thickening than the fast-progressors during the treatment phase regardless of the treatment group (P < 0.001), but choroidal thickening in the atropine group's fast-progressors was not sustained after stopping eye drops. CVI decreased in both groups during the treatment phase, but increased in the placebo group after treatment cessation. On average, compared to placebo, 0.01% atropine eye drop treatment did not cause a differential rate of change in ChT during treatment, but abrupt cessation of long-term 0.01% atropine eye drops may disrupt normal choroidal thickening in children.