Subfoveal Choroidal Thickness Measurements Research Articles

Comparison of manual and artificial intelligence-automated choroidal thickness segmentation of optical coherence tomography imaging in myopic adults

BackgroundMyopia affects 1.4 billion individuals worldwide. Notably, there is increasing evidence that choroidal thickness plays an important role in myopia and risk of developing myopia-related conditions. With the advancements in artificial intelligence (AI), choroidal thickness segmentation can now be automated, offering inherent advantages such as better repeatability, reduced grader variability, and less reliance for manpower. Hence, we aimed to evaluate the agreement between AI-automated and manual segmented measurements of subfoveal choroidal thickness (SFCT) using two swept-source optical coherence tomography (OCT) systems.MethodsSubjects aged ≥ 16 years, with myopia of ≥ 0.50 diopters in both eyes, were recruited from the Prospective Myopia Cohort Study in Singapore (PROMYSE). OCT scans were acquired using Triton DRI-OCT and PLEX Elite 9000. OCT images were segmented both automatically with an established SA-Net architecture and manually using a standard technique with adjudication by two independent graders. SFCT was subsequently determined based on the segmentation. The Bland–Altman plot and intraclass correlation coefficient (ICC) were used to evaluate the agreement.ResultsA total of 229 subjects (456 eyes) with mean [± standard deviation (SD)] age of 34.1 (10.4) years were included. The overall SFCT (mean ± SD) based on manual segmentation was 216.9 ± 82.7 µm with Triton DRI-OCT and 239.3 ± 84.3 µm with PLEX Elite 9000. ICC values demonstrated excellent agreement between AI-automated and manual segmented SFCT measurements (PLEX Elite 9000: ICC = 0.937, 95% CI: 0.922 to 0.949, P < 0.001; Triton DRI-OCT: ICC = 0.887, 95% CI: 0.608 to 0.950, P < 0.001). For PLEX Elite 9000, manual segmented measurements were generally thicker when compared to AI-automated segmented measurements, with a fixed bias of 6.3 µm (95% CI: 3.8 to 8.9, P < 0.001) and proportional bias of 0.120 (P < 0.001). On the other hand, manual segmented measurements were comparatively thinner than AI-automated segmented measurements for Triton DRI-OCT, with a fixed bias of − 26.7 µm (95% CI: − 29.7 to − 23.7, P < 0.001) and proportional bias of − 0.090 (P < 0.001).ConclusionWe observed an excellent agreement in choroidal segmentation measurements when comparing manual with AI-automated techniques, using images from two SS-OCT systems. Given its edge over manual segmentation, automated segmentation may potentially emerge as the primary method of choroidal thickness measurement in the future.

Longitudinal Changes in Choroidal Thickness Varied With Refractive Progression in Myopic and Non-Myopic Children: A Two-Year Cohort Study.

To evaluate the longitudinal changes in subfoveal choroidal thickness (SFCT) in children with different refractive status. A total of 2290 children 3 to 14years old who attended the first year of kindergarten (G0), first year of primary school (G1), fourth year of primary school (G4), or first year of junior high school (G7) in Guangzhou, China, were recruited and followed up for 2years. All participants received cycloplegic autorefraction, axial length measurement and SFCT measurement using a CIRRUS HD-OCT device. Children were divided into groups of persistent non-myopia (PNM), persistent myopia (PM), or newly developed myopia (NDM). Children in the PNM and PM groups were further divided into subgroups of stable refraction (absolute mean annual spherical equivalent refraction [SER] change < 0.5D) and refractive progression (absolute mean annual SER change ≥ 0.5D). The mean ± SD ages for the G1 to G7 cohorts were 3.89 ± 0.30, 6.79 ± 0.47, 9.71 ± 0.34, and 12.54 ± 0.38, years, respectively. SFCT consistently decreased in the NDM group across the G1 to G7 cohorts (all P<0.001) and exhibited variability across different age cohorts in the PNM and PM groups. Further subgroup analysis revealed significant thickening of SFCT in the PNM-stable group among the G0, G1, and G7 cohorts (all P<0.05), whereas it remained stable among all cohorts in the PM-stable group (all P>0.05). Conversely, SFCT exhibited thinning in the G4 and G7 cohorts in the PM-progressive group (both P<0.01) and for the entire cohort of children in the PNM-progressive group (P=0.012). SFCT increased in nonmyopic children with stable refraction, remained stable in myopic children maintained stable refraction, and decreased in those with refractive progression, whether they were myopic or not.

Mean Amplitude of Diurnal Variation of Sub-Foveal Choroidal Thickness among Adults with Healthy Eyes Visiting Outpatient Department of a Tertiary Eye Care Centre.

The choroid, particularly the choroidal vasculature, plays an important role in the pathophysiology of various ocular diseases. Diurnal variation in the thickness of the choroid has been reported in previous studies. This study aimed to find the mean amplitude of diurnal variation of sub-foveal choroidal thickness among adults with healthy eyes visiting the outpatient Department of a tertiary eye care centre. A descriptive cross-sectional study was conducted among adults with healthy eyes presenting to the outpatient Department of a tertiary eye care centre from 1 February 2023 to 3 June 2023 after obtaining ethical approval from the Institutional Review Committee. After a comprehensive medical eye examination, sub-foveal choroidal thickness measurement was performed using enhanced depth imaging optical coherence tomography at the baseline and subsequent interval afterwards. A convenience sampling method was used. The point estimate was calculated at a 95% Confidence Interval. Among 60 eyes, the mean amplitude of the diurnal variation of subfoveal choroidal thickness was 35.16±14.08 microns (31.59-38.72, 95% Confidence Interval). The mean amplitude for the right eye was 36.30±14.08 microns, and for the left eye, it was 34.23±14.08 microns. The amplitude of diurnal variation of subfoveal choroidal thickness from this study was found to be similar to other studies done in international settings. choroid; circadian rhythm; cross-sectional study; Ophthalmology.

Impaired brachial flow-mediated dilation may predict choroidal and retinal nerve fibre layer thickness changes in people with obesity

ABSTRACT Clinical relevance Choroidal thickness and peripapillary retinal nerve fibre layer (RNFL) changes are known to occur in obesity. Endothelial dysfunction and systemic atherosclerosis may play a role in the pathophysiology of these differences. Background Flow-mediated dilation (FMD) is reduced in patients with endothelial dysfunction, and the ankle-brachial index is a surrogate marker for atherosclerosis. This study was conducted to examine the relationship between systemic vascular parameters (FMD, and ankle-brachial index), subfoveal choroidal thickness, and peripapillary RNFL thickness in obese individuals. Methods This observational, cross-sectional study involved 108 total participants who were divided into two groups. One group consisted of 54 obese subjects who each had a body mass index of 30 kg/m2 or more. The other control group contained 54 participants who each had a body mass index of 25 kg/m2 or less but higher than 20 kg/m2 . For each participant, only one eye was examined in this study. Subfoveal choroidal thickness, RNFL thickness, ankle-brachial index, and ultrasound measurement of the brachial artery FMD were performed. FMD was categorised according to receiver operating characteristic analysis, and endothelial dysfunction was defined as an FMD ≤ 7.29%. Results Subfoveal choroidal and RNFL thicknesses in the temporal quadrant were significantly lower in the obese group (p < 0.05). Lower mean values of subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants were observed in subjects with an FMD ≤ 7.29% (p < 0.05). In people with obesity, FMD was positively correlated with subfoveal choroidal thickness (r = 0.322, p = 0.001), inferior RNFL thickness (r = 0.259, p = 0.007), and temporal RNFL thickness (r = 0.297, p = 0.002). However, the ankle-brachial index was not correlated with obesity. Conclusions Impaired FMD was associated with reduced subfoveal choroidal and RNFL thicknesses in the temporal and inferior quadrants of people with obesity.

Evaluation of macular choroidal and microvascular network changes by activity scores and serum antibodies in thyroid eye patients and healthy subjects.

To investigate the choroidal thickness and the microvascular network changes around the macula in thyroid eye disease (TED) patients at different stages and the relationship of those changes with risk factors, serum antibodies and the severity of TED. A total of 85 participants were enrolled. All participants underwent ophthalmology and endocrinology examinations. Subfoveal choroidal thickness (SFCT), superficial (s) and deep (d) foveal avascular zone (FAZ) area, mean (m) and central (c) superficial vascular density (SVD), deep vascular density (DVD) measurements of the enrolled cases were performed with Topcon swept source optical coherence tomography (OCT)/OCT angiography (OCTA) DRI OCT Triton. Multiple linear regression analysis was used to explore the associations between SFCT, FAZ area, SVD, DVD and the relevant factors of TED. Those with active TED patients had higher c-DVD and m-DVD levels (P<0.05), however there is no statistically significant difference in SFCT between active and stable TED patients. Among the serum antibodies, it was observed that s-FAZ and d-FAZ increased, c-SVD and m-SVD decreased in patients with high thyroid stimulating hormone-receptor autoantibodies (TRAB) level, whereas SFCT thickened in patients with high levels of both TRAB and human thyroglobulin (hTG). There was no significant difference in SFCT, FAZ, SVD and DVD measurement at gender, between hyperthyroid and euthyroid patients and among those with or without thyroid papillary carcinoma. The results show that both disease activation and serum antibodies differentially affect both superficial and deep retinal vascular density. It has also been shown that high serum antibody levels affect choroidal thickness independent of clinical activity.

Measurement of Sub-Foveal Choroidal Thickness in Hyperthyroid Patients with Thyroid Associated Ophthalmopathy, Using Spectral Domain OCT

Background Thyroid associated ophthalmopathy (TAO) is an auto-immune orbitopathy, associated with thyroid dysfunction. It results in compression of the orbital contents, impairment of the blood flow and thus affects the choroidal and retinal microstructure and function. Aim of the Work The purpose of this study is to measure the central choroidal thickness in active and inactive TAO using Optical Coherence Tomography (OCT) and compare it to the control group. Patients and Methods The cross section study was conducted on participants recruited from the ophthalmology clinic of the National Institute of Diabetes and Endocrinology (NIDE). The study included 160 eyes from 80 participants (40 hyperthyroidism patients and 40 control subjects). Data was collected during the period of December 2019 to June 2020. Results There was no significant difference regarding age, gender, vision and IOP between TAO patients (either active or inactive) and normal subjects. Our study showed that there was a significant increase in sub-foveal choroidal thickness in patients with TAO compared to the control group. It also showed a significant increase in sub-foveal choroidal thickness in the active subgroup more than the inactive subgroup. In addition, a decrease in central foveal thickness was found in patients with TAO compared to the control group, but there was no significant difference found between active and inactive subgroups. Conclusion The findings of this study suggest that there is a significant affection of sub-foveal choroidal thickness and central foveal thickness in thyroid-associated-ophthalmopathy (TAO) patients.

Decreased choroidal vascularity index and subfoveal choroidal thickness in vitamin D insufficiency

BackgroundTo present the effects of vitamin D insufficiency on the choroidal vascularity index, central choroid and central macula. Methods42 eyes of 42 patients with vitamin D insufficiency and 51 eyes of 51 age- and sex-matched healthy subjects were included in this retrospective, cross-sectional, and comparative study. The macular layer was examined using the retinal mapping mode of the spectral domain Optical coherence tomography (Optovue RTVue XR, Optovue Inc., Fremont, CA). Optical coherence tomography (OCT) images were taken in Enhanced Deep Imaging mode and transferred to Image J program. choroidal vascularity index (CVI) and subfoveal choroidal thickness (SFCT) measurements were evaluated. ResultsThe mean age of volunteers was 35.4 ± 7.2 years. There was a significant difference in CVI values 67.75±2.4 in the patients with vitamin D insufficiency and 69.22±1.75 in the control group. The SCFT of patients with vitamin D insufficiency and control group were 295.25±42.3 and 335.71±11.6 (p = 0.001, p<0.001 respectively). ConclusionOCT examination of patients with vitamin D insufficiency showed a decrease in CVI and SCFT values. These results are important in demonstrating the retinochoroidal effects of vitamin D insufficiency.

Impact of Valsalva manuever on choroidal vascularity index, central choroid and central macula

BackgroundEvaluation of the effects of the Valsalva maneuver on choroidal vascularity index, central choroid and the central macula. MethodsEighty-four eyes of 42 healthy volunteers were evaluated in this prospective study. The central macular layer was assesed using the retinal map mode of the spectral domain OCT (Optovue RTVue XR, Optovue Inc., Fremont, CA), OCT images taken in the Enhanced Deep Imaging mode were transferred to the Image J program and the choroidal vascularity index and subfoveal choroidal thickness measurements were calculated. ResultsThe mean age of volunteers was 35.4±7.2 years. Choroidal vascularity index, subfoveal choroidal thickness, central macular thickness and intraocular pressure measurements in the resting position were 67.99±2.1%, 337.73±12.8 µm, 232.04± 8.4 µm, 14.04±2.5 mmHg respectively, during Valsalva maneuver were 69.44±2.1%, 351.15±12.2 µm, 238.84±8.1 µm, 19.4±5.4 mmHg respectively. There was a statistically significant increase during Valsalva maneuver. ConclusionThe Valsalva maneuver may cause temporary changes in choroidal vascularity index, subfoveal choroidal thickness, central macular thickness and intraocular pressure. These measurements may be misinterpreted in situations where patients breath-hold inadvertantly causing the Valsalva maneuver.

Choroidal Vascularity Index and Choroidal Thickness Changes Following Renal Transplantation.

This study aimed to evaluate changes in subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), estimated glomerular filtration rate (GFR), mean arterial pressure (MAP), and intraocular pressure (IOP) after renal transplantation. A total of 49 renal transplantation patients were included in this prospective study. CVI and SFCT on enhanced-depth imaging optic coherence tomography (EDI-OCT), MAP at the cubital fossa, GFR, and IOP were measured preoperatively and at postoperative 1 week and 1 month. In the analysis of EDI-OCT images, luminal area (LA) and stromal area of the choroid were determined using the image binarization method. CVI was defined as the ratio of LA to total choroid area. The effects of GFR, IOP, and MAP on CVI and SFCT were investigated. The study included 23 women (47%) and 26 men (53%) with a mean age of 26.28±8.25 years (range: 18-52). Changes between preoperative, postoperative 1-week, and postoperative 1-month GFR values, CVI, and SFCT measurements were evaluated. There were significant differences between preoperative and postoperative GFR and SFCT measurements (p<0.001), but no significant differences between preoperative and postoperative CVI (p=0.09), MAP (p=0.14), or IOP (p=0.84) measurements. The present study demonstrated that SFCT increased significantly with GFR, while there was no change in CVI values.

Edi Mod Spectral Domain Optical Coherence Tomography Evaluation of The Choroid in Retinitis Pigmentosa: A Case-Control Study

Objective: The evaluation of choroidal thickness measurements became possible after the developments in optical coherence tomography (OCT) technology. This study aimed to evaluate choroidal features in Retinitis Pigmentosa subjects with EDI (Enhanced depth imaging) mode spectral domain optical coherence tomography (SD-OCT). Material and Method: A hundred and three eyes of 54 RP subjects underwent scanning with EDI-OCT for central retinal and choroidal thickness measurements and were compared with 40 healthy controls. Submacular choroidal thickness measurements were obtained beneath the fovea and at 500 µm intervals for 2.5 mm nasal and temporal to the center of the fovea. Results: Mean subfoveal choroidal thickness measurements were 253.2±74.9 µm in RP patients and 336.2±91.7 µm in control (p&lt;0.0001). There was no correlation between subfoveal choroidal thickness and visual acuity in RP patients. The choroid had an irregular shape in 85 % of RP patients. The thickest point of the choroid was not subfoveal as in healthy eyes, and excessive nasal thinning of the choroid was observed in 93 % of RP patients. Conclusion: Submacular choroidal thickness was significantly reduced but did not correlate with the visual acuity in RP patients.

Investigation of changes in retinal vascular parameters and choroidal vascular index values during the early recovery period of COVID-19: The COVID-OCTA study

BackgroundCOVID-19 effects microvasculature in many tissues. This study investigated whether the choroidal structure is also affected. MethodsThis cross-sectional study included 80 patients with COVID-19 and the same number of age- and gender-matched healthy individuals. All participants' right eye measurements were examined. Optical coherence tomography angiography (OCTA) was used for imaging. Otherwise, two independent researchers used the Choroidal vascular index (CVI) for choroidal parameters calculation. ResultsSuperior and deep flow values were lower in the COVID-19 group than in the control group, and vascular density (VD) values were lower in all regions in this group. Except for the superior mean VD, there was no statistically significant difference (p = 0.003). However, the COVID-19 group had significantly lower subfoveal choroidal thickness (SFChT) measurements than the control group (p = 0.001). In addition, no significant difference was observed between the groups in evaluating mean CVI values (p>0.05). ConclusionNoninvasive diagnostic tools such as OCTA and EDI-OCT can be used to monitor early changes in diseases affecting microvessels, such as from COVID-19.

Measurement of sub-foveal choroidal thickness in hyperthyroid patients with thyroid associated ophthalmopathy using spectral domain OCT

Measurement of sub-foveal choroidal thickness in hyperthyroid patients with thyroid associated ophthalmopathy using spectral domain OCT

Effect of panretinal photocoagulation on retina and choroid in diabetic retinopathy: An optical coherence tomography angiography study

BackgroundTo analyze the quantitative changes in both macular, and choroidal thickness, and microvascularization after panretinal photocoagulation (PRP) in eyes with proliferative diabetic retinopathy (PDR) or severe non-proliferative diabetic retinopathy (NPDR) by using optical coherence tomography angiography (OCT-A). MethodsThe patients diagnosed with severe NPDR or PDR according to the Early Treatment Diabetic Retinopathy Study (ETDRS) and decided to be treated with PRP were included in this prospective and observational study. Ten eyes of 10 patients with PDR and twelve eyes of 12 patients with severe NPDR were examined. Macular scans (6 × 6 mm) were obtained from OCT-A at baseline and at month 6 after PRP. Subfoveal choroidal thickness (SFCT) measurements that were obtained through the foveolar center on a high-definition line scan were recorded. ResultsBest-corrected visual acuity (BCVA) significantly decreased (p = 0.018), central foveal thickness and mean parafoveal thickness significantly increased (p < 0001 and p < 0.001, respectively) six months after PRP. The thickness of all parafoveal retinal quadrants (temporal, superior, nasal, inferior) increased (p = 0.001, p = 0.003, p < 0.001, p < 0.001, respectively) and mean parafoveal, parafoveal temporal, and parafoveal nasal vessel density of the deep capillary plexus (DCP) significantly decreased six months after PRP compared with the baseline values (p = 0.023, p = 0.041, p = 0.018, respectively). ConclusionsThe parafoveal vessel density of DCP decreased significantly 6 months after PRP in eyes with PDR or severe NPDR. While the difference in SFCT and choroidal flow density was not significant from the baseline; central and parafoveal retinal thickness increased and BCVA decreased significantly 6 months after PRP treatment.

Macula, choroid and retinal nerve fiber layer optical coherence tomography biomarkers in liver dysfunction

Abstract Objectives We aimed on evaluating the effect of liver dysfunction on retinal nerve fiber layer (RNFL), GCL++ (ganglion cell layer + RNFL + inner plexiform layer), central macular thickness (CMT) and subfoveal choroidal thickness (CT) measurements. Methods Fifty two patients with primary biliary cirrhosis (PBC group) and 61 healthy individuals (control group) were included in our study. Blood alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), total bilirubin, albumin, prothrombin time results as the international normalized ratio (INR), neutrophil (NEUT), lymphocyte (LYMP), neutrophil lymphocyte rate (NLR), platelet (PLT), mean platelet volume (MPV) levels were analyzed in both groups. RNFL, Inferior RNFL (IRNFL), Superior RNFL (SRNFL), GCL++, CMT and CT were measured by swept source optical coherence tomography (OCT). The choroidal vascular index (CVI) was also obtained. Results GGT (p=0.001), ALP (p&lt;0.001), albumin (p&lt;0.001), NEUT (p=0.046) and MPV (p&lt;0.001) values were higher in the PBC group. INR (p=0.017) and PLT (p=0.027) values were lower in the PBC group. CMT (p=0.015), CT (p=0.002), and GCL++ (p&lt;0.001) values were found lower in the PBC group. Conclusions OCT analyzes revealed thinning in CMT, CT and GCL++ in patients with liver dysfunction. OCT analyzes should be evaluated during periodic ocular examinations of PBC patients.

Evaluation of choroidal thickness and ocular manifestations in lipoid proteinosis.

To assess choroidal thickness in patients with lipoid proteinosis versus healthy subjects using enhanced depth imaging optical coherence tomography. Twenty eyes of 20 patients and the same number of age and sex-matched healthy individuals were enrolled. Comprehensive ocular examinations including measurement of best-corrected visual acuity, spherical equivalent values of refractive errors, and axial length were performed. Choroidal thickness at three points (subfoveal, 500µm nasal and temporal regions) were measured automatically using MATLAB software. The mean age was 15.68 ± 5.98years in the patient group and 16.48 ± 5.69years in the control group. Mean choroidal thickness was statistically significantly thicker at each point in patients with lipoid proteinosis compared to the healthy controls: subfoveal, temporal and nasal choroidal thickness measurements were 425.65 ± 51.42, 380.20 ± 69.66, 334.05 ± 49.98µm in the study group; 346.15 ± 47.76, 330.15 ± 44.35, 298.95 ± 44.21µm in the control group, respectively (P < 0.05). Patients with lipoid proteinosis have thicker choroid compared to control eyes. Hyalin deposition and ensuing potential inflammation in the disease process may explain this finding.

Evaluation of Choroidal Vascular Index in Amblyopic Patients.

Objectives:To compare subfoveal choroidal thickness (SFCT) and choroidal vascular index (CVI) in patients with hyperopic refractive and strabismic amblyopia and healthy subjects.Materials and Methods:The study included 17 patients with strabismic amblyopia (Group 1), 29 patients with hyperopic refractive amblyopia (Group 2), and 16 eyes of 16 healthy volunteers (Group 3). Best corrected visual acuity was noted in all patients and volunteers. In addition to detailed anterior and posterior segment examinations, macular images were obtained by enhanced-depth imaging mode of optical coherence tomography (OCT). SFCT measurements were made from these images and CVI was calculated using the Image J program.Results:No significant difference was found between the groups in terms of age, gender, and intraocular pressure (p=0.27, 0.64, and 0.85, respectively). Mean BCVAs in Group 1 were 0.57±0.16 (0.3-0.8) in the amblyopic eyes, 0.94±0.08 (0.8-1.0) in the fellow eyes, and in Group 2 were 0.61±0.17 (0.2-0.8) in amblyopic eyes, 0.92±0.1 (0.8-1.0) in fellow eyes. BCVA in Group 3 was 1.0±0 (1.0-1.0). Mean SFCT of the amblyopic eyes in Groups 1 and 2 was 341.50±60.4 (277-481) and 370.06±65.3 (247-462), respectively, and in the healthy eyes of Groups 1 and 2 and Group 3 was 321.92±68.26 (251-440), 330.35±74.00 (194-502), and 327.62±40.79 (238-385), respectively. SFCT was significantly greater in the amblyopic eyes of Group 2 compared to Group 3 (p=0.01). Mean CVI was 0.681±0.032 (0.642-0.736) in the amblyopic eyes and 0.685±0.054 (0.587-0.788) in the fellow eyes of Group 1 patients; 0.664±0.033 (0.592-0.719) in the amblyopic eye and 0.707±0.039 (0.625-0.779) in the fellow eye in Group 2 patients; and 0.689±0.031 (0.612-0.748) in Group 3 patients. CVI was significantly lower in the amblyopic eyes of Group 2 compared with fellow eyes (p=0.02) and Group 3 (p=0.025).Conclusion:Morphological changes may be seen in the choroid in amblyopic eyes. We observed that the choroidal stromal component is increased in hyperopic amblyopic patients especially.

Acute Effects of Coffee on Peripapillary and Subfoveal Choroidal Parameters in Young Healthy Subjects.

To evaluate the acute effects of coffee on peripapillary and subfoveal choroidal structures using spectral-domain optical coherence tomography (SD-OCT). A total of 28 healthy individuals (study group) and 28 healthy controls were enrolled in this study. The peripapillary and subfoveal choroidal thickness (SFCT) was measured at baseline, 30 min, 1 h, 2 h, and 4 h, following coffee (75 mg caffeine/200 ml) intake in the study group and the same amount of water in the control group. Choroidal images were binarized to the luminal area (LA), stromal area (SA), and total choroidal area (TCA) using ImageJ software. Similar to the CT, the peripapillary and subfoveal choroidal vascularity indices (CVIs) were calculated at the same time points in both groups. CT and CVI measurements of four peripapillary quadrants displayed no significant difference at baseline and all-time points in both groups (p > 0.05). In the study group, SFCT was found to be significantly lower (at 30 min, 1 h, 2 h, and 4 h) than the baseline measurement (p < 0.05). Additionally, subfoveal LA, TCA, and CVI decreased in all-time points compared with baseline measurements (p < 0.05, for all). This was not true for the subfoveal SA (p > 0.05). No significant difference was found between the respective SFCT and subfoveal CVI measurements in the control group (p > 0.05, for all). Our study revealed that peripapillary choroidal thickness and CVI did not change following a cup of coffee intake, while subfoveal CT, LA, TCA, and CVI significantly decreased for at least 4 h.

Retinal Optical Coherence Tomography Angiography Findings following Retinoblastoma Treatment by Chemotherapy.

To investigate the macular microvascular changes after different kinds of chemotherapy in patients with extramacular retinoblastoma (RB). In this study, 28 eyes of 19 patients with bilateral RB treated with intravenous systemic chemotherapy (IVSC group) and 12 eyes of 12 patients with unilateral RB treated with intra-arterial chemotherapy (IAC group) were compared with 6 normal fellow eyes of 6 patients with unilateral RB treated with IVSC (IVSC fellow eye group), and 7 normal fellow eyes of 7 unilateral RB patients treated with IAC (IAC fellow eye group), as well as 12 age-matched normal eyes. Enhanced depth imaging optical coherence tomography measurements of central macular and subfoveal choroidal thickness (CMT and SFCT) as well as optical coherence tomography angiography measurements such as retinal superficial capillary density (SCD), deep capillary density (DCD), and choriocapillaris density were documented. Images of 2 eyes in the IVSC group and 8 eyes in the IAC group were excluded from the final image analysis due to severe retinal atrophy. Overall, 26 eyes with bilateral RB treated with IVSC and 4 eyes of 4 patients with unilateral RB treated with IAC were compared with the mentioned control groups. Best-corrected visual acuity was 1.03 logMAR in the IAC patients compared to 0.46 logMAR in the IVSC group at the time of imaging. While the CMT and SFCT were lower in the IAC group in comparison with the IAC fellow eye and normal groups (P < 0.05 for all), no remarkable difference was observed between the IVSC group and the control groups based on the mentioned parameters. Although the SCD showed no significant difference between the IVSC and control groups, this parameter was significantly lower in the eyes receiving IAC relative to the corresponding fellow eye group (P = 0.042) and normal control eyes (P = 0.047). The mean DCD was considerably lower in both the treatment groups compared to the control groups (P < 0.05 for all). Our study showed a substantial decrease in SCD, DCD, CMT, and choroidal thickness in the IAC group, which may explain the lower visual outcome in this group.

The effect of branch retinal vein occlusion on the vascular structure of the choroid

ObjectiveOur aim is to examine choroidal structural changes in eyes with branch retinal vein occlusion (BRVO). Material and MethodThis retrospective, comparative study included 34 newly diagnosed unilateral BRVO patients and 40 healthy controls. Subfoveal choroidal thickness (SFCT) measurement was performed with enhanced depth imaging optical coherence tomography (EDI-OCT). The images were binarized using the ImageJ software program. Total choroidal area (TCA), stromal area (SA), and luminal area (LA) were calculated from the 1500 µm area. The choroidal vascular index (CVI) was determined as the LA/TCA ratio. All parameter values were compared between the BRVO eye and the fellow eye, and the control group eyes. ResultsEyes with BRVO had a greater SA compared to both fellow and control eyes; hence, the CVI was lower (p < 0.001). LA did not differ between eyes. TCA, although not statistically significant, was larger in eyes with BRVO than in both fellow and control eyes. SFCT was also greater in eyes with BRVO. No correlation was observed between CVI and SFCT and best-corrected visual acuity (BCVA). ConclusionBRVO affects the stromal part of the choroid rather than its vascular structure. SA increases due to choroidal exudation that occurs in response to retinal ischemia, and CVI decreases accordingly.

Short-term changes in retinal and choroidal relative flow volume after anti-VEGF treatment for neovascular age-related macular degeneration

The effects of anti-vascular endothelial growth factor (anti-VEGF) agents on the native ocular vasculature are poorly understood. This pilot study aimed to assess short-term changes in retinal and choroidal perfusion after anti-VEGF treatment for neovascular exudative age-related macular degeneration (nAMD) using the relative flow volume (RFV) parameter derived from laser speckle flowgraphy. Ten treatment-naïve nAMD patients underwent measurements of mean, maximum, minimum, and differential RFV within a retinal arteriolar segment and a choroidal vessel segment outside the neovascular area. Measurement of retinal RFV (rRFV), choroidal RFV (cRFV), and subfoveal choroidal thickness (SCT) was repeated 9 and 35 days after a single anti-VEGF injection. The treatment caused a statistically significant decrease in the mean rRFV, mean cRFV, and SCT during the follow-up (p < 0.05). At the intermediate visit, the mean cRFV and SCT were − 17.6% and − 6.4% compared to baseline, respectively. However, at the final measurement, the mean cRFV was not different from the baseline value, which indicated waning of the anti-VEGF effect. In conclusion, a single anti-VEGF injection in treatment-naïve nAMD resulted in a decrease in retinal arteriolar and choroidal perfusion, according to the RFV parameter, which is a promising tool to simultaneously assess retinal and choroidal perfusion changes in response to anti-VEGF therapy.