Choroidal Thickness Increases During Parasympathetic Dominance After Immersion of the Foot in Warm Water.

PURPOSE: This study aimed to assess the course of changes in choroidal morphology after immersion of the foot in warm water at 40°C using enhanced depth imaging optical coherence tomography (EDI-OCT). METHODS: Forty-three right eyes of 43 healthy participants were included. Changes in choroidal morphology were determined using EDI-OCT to evaluate subfoveal choroidal thickness (SCT). Systolic, diastolic, and mean blood pressures (SBP, DBP, and MBP, respectively) were also measured to determine systemic circulatory dynamics at baseline, immediately after immersion (0 min), and 10, 20, and 30 min after immersion. RESULTS: Immediately after immersion, SBP, DBP, and MBP were significantly declined versus baseline. In contrast, the SCT was significantly increased after warm water immersion. However, all these parameters did not change significantly compared to the baseline within 30 min. CONCLUSION: In the normal eye, parasympathetic nerve activity induced by warming stimuli increases choroidal morphology in response to a decrease in systemic circulatory activity, which normalizes within 30 min. The findings of this study may provide basic data for the prevention and treatment of various choroidal diseases in which sympathetic hyperactivity is involved in the pathogenesis.

The Association Between Choroidal Thickness and Meniere's Disease: A Cross-Sectional Study.

OBJECTIVE: To evaluate and compare choroidal thickness (CT) between patients with Meniere's disease (MD) and a control group. METHODS: This case-control analytical study was conducted on 37 subjects with MD and 37 healthy subjects. Subfoveal CT (SCT), large choroidal vessel (LCV) layer thickness, and mean subfoveal LCV thickness/mean SCT ratio were measured using enhanced-depth imaging optical coherence tomography (EDI-OCT) in the eyes on the MD side (ipsilateral), the contralateral eyes, and the control group. RESULTS: A statistically significant difference was observed in the mean SCT values between the ipsilateral and control groups after adjustment for age, sex, and migraine (p = 0.04). Moreover, there was a statistically significant difference between the mean subfoveal LCV thickness values and the mean subfoveal LCV thickness/mean SCT ratio between the ipsilateral and control groups (p = 0.006, and p < 0.001, respectively). Patients with a duration of disease over three years had a greater mean subfoveal LCV thickness/mean SCT ratio (67.35 ± 11.56 and 60.66 ± 11.27, respectively), which was statistically insignificant (p = 0.08). CONCLUSION: We found a thicker choroid and Haller layer, and a greater subfoveal LCV thickness/SCT ratio on the MD side compared to the controls. Furthermore, patients with a greater duration of disease had a lower subfoveal LCV thickness/SCT ratio. These findings may reflect the role of the trigeminal vascular system (TVS) and neurovascular pathophysiology in MD patients. More extensive studies are required to reach more definitive conclusions about the association between CT and MD. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1889-1893, 2024.

Choroidal Morphology and Systemic Circulation Changes During the Menstrual Cycle in Healthy Japanese Women.

PURPOSE: Changes in systemic circulatory dynamics and choroidal thickness are poorly understood. This study aimed to investigate the time course of changes in choroidal morphology during normal menstrual cycles in healthy women using enhanced depth imaging optical coherence tomography (EDI-OCT). MATERIALS AND METHODS: This prospective study included 15 left eyes of 15 healthy Japanese women (mean age, 20.2 ± 0.8 years) with a normal menstrual cycle. Using EDI-OCT, the subfoveal choroidal thickness (SCT) was manually measured during the late follicular and mid-luteal phases. Intraocular pressure (IOP), systolic, diastolic, and mean blood pressure (SBP, DBP, and MBP), and heart rate (HR) were also evaluated during these phases. RESULTS: SBP, DBP, and MBP were significantly elevated in the mid-luteal phase. The average SCT was significantly decreased in the mid-luteal phase. In contrast, there were no significant changes in IOP or HR. CONCLUSION: These findings indicate that choroidal thickness decreases during the mid-luteal phase in healthy Japanese women with normal menstrual cycles depending on systemic circulatory dynamics. However, since the difference in the SCT values between the late follicular and the mid-luteal phase is not large (7 µm), the menstrual cycle may have little influence on the interpretation of choroidal thickness data in clinical practice.

Retinal and Choroidal Changes Following Implantable Collamer Lens V4c Implantation in High Myopia Patients-A 1-Year Follow-Up Study.

This prospective study aimed to evaluate the impact of Visian Implantable Collamer Lens (ICL) V4c implantation on retinal and choroidal morphology in patients with high myopia. A total of 97 eyes from 52 high myopic patients who underwent ICL V4c implantation were followed up for 12 months. Preoperative and postoperative evaluations included comprehensive ophthalmic assessments and enhanced depth imaging optical coherence tomography (EDI-OCT) to analyze changes in central retinal thickness (CRT), retinal volume (CRV), choroidal thickness (ChT), total choroidal area (TCA), luminal area (LA), and choroidal vascular index (CVI). Repeated measures mixed-effects models were used for comparing pre- and postoperative measurement variables and exploring relationships among age, axial length (AL), spherical equivalent refraction (SER), and postoperative retinal and choroidal changes, with statistical significance set at p < 0.05. Follow-up assessments were conducted at various time points, with participation rates ranging from 21% to 98%. Baseline characteristics showed a median age of 26.7 years, -10.14 diopters of SER, and an AL of 27.44 mm. Throughout the 12-month follow-up, CRT and 3.0 mm CRV consistently increased compared to the baseline, with statistically significant rises observed at postoperative day 1, week 1, and month 12. Most ChT measurements, including subfoveal ChT, declined over the 12 months, except at postoperative 6 months. Horizontal and vertical TCA and LA values significantly increased throughout the follow-up, except for month 6. After surgery, both horizontal and vertical CVI parameters exhibited an increase compared to the baseline, with some changes reaching statistical significance. Correlation analysis performed by repeated measures mixed-effects models showed that no relationship was found between age, AL, and SER and changes in postoperative retinal parameters and CVI parameters. However, postoperative changes in ChT and choroidal area parameters showed a negative correlation with AL and a positive correlation with SER. Our research demonstrated that ICL V4c implantation resulted in noteworthy alterations in retinal and choroidal morphology over a 1-year follow-up period. Moreover, in patients with high myopia, individuals with longer AL and higher degrees of myopia exhibited more pronounced postoperative changes in the choroid and retina. Further studies with extended follow-up durations are necessary to comprehensively understand the long-term effects of ICL implantation on retinal and choroidal morphology and function.

Evaluation of Choroidal Vascularity Index in Keratoconus Patients: Does Choroidal Vascularity Change in Keratoconus?

Purpose: To investigate the choroidal structure in keratoconic patients with different severity using the choroidal vascularity index (CVI) derived from image binarization on enhanced depth imaging optical coherence tomography scans (EDI-OCT). Methods: Sixty-eight eyes from 34 keratoconus (KCN) patients and 72 eyes from 36 healthy subjects were recruited in this prospective, noninterventional, comparative cross-sectional study. EDI-OCT was employed to measure choroidal parameters, including choroidal thickness (CT), total choroidal area (TCA), luminal area, stromal area, and CVI. Results: Subfoveal CT was 354.6 ± 66.8 µm in the control group and 371 ± 64.5 µm in the KCN group (P = 0.86). There was no significant difference between control and KCN groups in terms of TCA (0.66 ± 0.14 mm2 vs. 0.7 ± 0.12 mm2; P = 0.70), luminal area (0.49 ± 0.10 mm2 vs. 0.53 ± 0.08 mm2; P = 0.67), and stromal area (0.16 ± 0.05 mm2 vs. 0.17 ± 0.05 mm2; P = 0.84). CVI was also comparable in the control group (75.4% ±3.4%) and the KCN group (75.6% ±4.5%; P = 0.43). There was also no significant correlation between other choroidal parameters and KCN severity indices. Conclusion: It seems that CVI as well as other choroidal biomarkers were not significantly different between patients with KCN and healthy subjects.

Effects of Sinovac-Coronavac and Pfizer-BioNTech mRNA vaccines on choroidal and retinal vascular system.

PURPOSE: To evaluate the effects of Sinovac-Coronavac and Pfizer-BioNTech mRNA vaccines on choroidal and retinal vascular system using enhanced depth imaging optical coherence tomography (EDI-OCT) and optical coherence tomography angiography (OCTA). METHODS: In this prospective cross-sectional study, 63 healthy participants (29 with Pfizer-BioNTech, 34 with Sinovac-CoronaVac) were evaluated after the first dose of vaccination. Vessel density (VD) of the superficial (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) were measured with OCTA. Choroidal thickness (CT) were measured with EDI-OCT. Measurements were performed at the 2nd week and the 4th week after vaccinations and compared to pre-vaccination values. RESULTS: Regarding Pfizer-BioNTech vaccination, CT in the subfoveal and nasal region significantly increased between the pre-vaccination and post-vaccination 2nd week and then significantly decreased to pre-vaccine values at 4th week. The SCP-VD (whole image, fovea, parafovea, perifovea temporal) variables showed a significant decrease at 2nd week. The DCP-VD inferior hemi, parafovea inferior hemi, parafovea inferior variables demonstrated a significant decrease at 2nd week. The perifovea DCP-VD variables also showed a significant decrease at 2nd week, and these variables returned to pre-vaccination values after 4 weeks. The CC-VD variables showed a significant decrease between pre-vaccine and 2nd week post-vaccination. Regarding the Sinovac-CoronaVac vaccination, there was no statistically significant difference in CT and VD values before and after vaccination (p> 0.05). CONCLUSION: Our study showed significant alterations in retinal vascular density and CT for the Pfizer-BioNTech vaccine at the 2nd week, and these parameters became compatible with pre-vaccination values at the 4th week. In contrast, no differences were observed after the Sinovac-Coronovac vaccination.

Choroidal thickness and choroidal vascularity index changes in children with type 1 diabetes mellitus without retinopathy.

BACKGROUND: Diabetic retinopathy is one of the most important causes of low vision in the working age group. Retinopathy findings start earlier and have a worse prognosis in type 1 DM. The aim of the this study was to compare the choroidal thickness (CT) and choroidal vascular index (CVI) values of type 1 diabetes mellitus (DM) patients without retinopathy findings in pediatric patients and healthy children. METHODS: The study included 89 children, including 43 type 1 DM patients and 46 healthy controls. The age, gender, duration of DM, hemoglobin A1c (HbA1c), refractive error, intraocular pressure (IOP) and axial length (AL) of the participants were noted. CT measurements were performed subfoveally, 1000 µm from the fovea in the nasal and temporal quadrants. The total choroidal area (TCA), luminal area (LA) and stromal area (SA) were calculated using the binarization method using the image J program. The CVI was determined by dividing the luminal area by the total choroidal area. RESULTS: There were no significant differences between the participants in terms of age, gender, spherical equivalent, IOP, and AL. There was no significant difference between the groups in terms of CT. TCA, LA and SA values were significantly higher in the Type 1 DM group (p=0.034, p=0.036, p=0.037, respectively). There was no significant difference between the groups in terms of the CVI. CONCLUSIONS: The TCA, LA, and SA values were significantly higher in the type 1 DM group. LA/SA and CVI values were lower in the type 1 DM group, although not significantly. There was a negative correlation between the duration of DM and LA/SA as well as CVI. This suggests that vascular reduction starts in the early stages.

Concomitant paracentral acute middle maculopathy and acute macular neuroretinopathy in eyes post-blunt trauma.

Purpose: To analyze the imaging characteristics and the clinical course of patients showing concomitant paracentral acute middle maculopathy (PAMM) and acute macular neuroretinopathy (AMN) post-blunt trauma. Methods: PAMM and AMN lesions post-blunt trauma diagnosed on enhanced depth imaging optical coherence tomography (EDI-OCT) were recruited for the study. Results: : Thirteen eyes of 13 individuals with a history of blunt trauma were included in the study, of whom 11 (85%) were males. Mean age of the patients was 33.62 (range 16-67) years. Mean visual acuity at presentation and the last visit was 1.67 log of minimum angle of resolution (logMAR) and 0.82 logMAR, respectively. Mean interval between trauma and imaging was 5.08 (range 1-15) days. All patients had unilateral involvement, with the right eye being involved in 10 patients (77%). All patients had concomitant PAMM and AMN lesions. Conclusion: : Presence of coincident PAMM and AMN suggests a common pathophysiologic etiology, but the description of concomitant PAMM and AMN in the setting of blunt trauma to eye is hitherto unreported. Identifying AMN in a setting of PAMM requires meticulous examination of the OCT and OCTA images. It can be a cause of suboptimal visual recovery in such eyes.

Quantitative Assessment of Choroidal Thickness and Choroidal Vascular Features in Healthy Eyes Based on Image Binarization of EDI-OCT: A Single-Center Cross-Sectional Analysis in Chinese Population.

PURPOSE: To quantify the structural changes in choroidal vessels and to observe choroid microstructural changes in different age and sex groups in a healthy Chinese population. METHODS: Enhanced depth imaging optical coherence tomography (EDI-OCT) was employed to analyze the luminal area, stromal area, total choroidal area, subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), large choroidal vessel layer (LCVL), choriocapillaris-medium choroidal vessel layer, and LCVL/SFCT of the choroid in the subfoveal macular area within 1500 µm of the macula. We analyzed the age- and sex-related changes in the subfoveal choroidal structure. RESULTS: A total of 1566 eyes from 1566 healthy individuals were included. The mean age of the participants was 43.62 ± 23.29 years, the mean SFCT of healthy individuals was 269.30 ± 66.43 µm, LCVL/SFCT percentage was 77.21 ± 5.84%, and the mean macular CVI was 68.39 ± 3.15%. CVI was maximum in the 0-10 years group, decreasing with age, and the lowest values occurred in the >80 years group; LCVL/SFCT was the lowest in the 0-10 years group, increasing with age and reaching a maximum in the >80 years group. CVI showed a significant negative correlation with age, and LCVL/SFCT showed a significant positive correlation with age. There was no statistically significant difference between males and females. Interrater and intrarater reliability was less variable with CVI than with SFCT. CONCLUSIONS: The choroidal vascular area and CVI decreased with age in the healthy Chinese population, of which the age-related decrease in vascular components maybe dominated by the decrease in choriocapillaris and medium choroidal vessels. Sex had no effect on CVI. The CVI of healthy populations showed better consistency and reproducibility when compared with SFCT.

Optical coherence tomography enhanced depth imaging of chorioretinal folds in patients with orbital tumors.

AIM: To characterize spectral-domain optical coherence tomography (SD-OCT) features of chorioretinal folds in orbital mass imaged using enhanced depth imaging (EDI). METHODS: Prospective observational case-control study was conducted in 20 eyes of 20 patients, the uninvolved eye served as a control. All the patients underwent clinical fundus photography, computed tomography, EDI SD-OCT imaging before and after surgery. Two patients with cavernous hemangiomas underwent intratumoral injection of bleomycin A5; the remaining patients underwent tumor excision. Patients were followed 1 to 14mo following surgery (average follow up, 5.8mo). RESULTS: Visual acuity prior to surgery ranged from 20/20 to 20/200. Following surgery, 5 patients' visual acuity remained unchanged while the remaining 15 patients had a mean letter improvement of 10 (range 4 to 26 letters). Photoreceptor inner/outer segment defects were found in 10 of 15 patients prior to surgery. Following surgical excision, photoreceptor inner/outer segment defects fully resolved in 8 of these 10 patients. CONCLUSION: Persistence of photoreceptor inner/outer segment defects caused by compression of the globe by an orbital mass can be associated with reduced visual prognosis. Our findings suggest that photoreceptor inner/outer segment defects on EDI SD-OCT could be an indicator for immediate surgical excision of an orbital mass causing choroidal compression.

Insights into the underlying choroid in different stages of idiopathic epiretinal membranes after Viteromacular surgery.

PURPOSE: The purpose of the study was to longitudinally investigate the correlation between choroidal morphologic and vascular parameters and postoperative visual outcome in different stages of idiopathic epiretinal membranes (iERMs). METHODS: A prospective, observational, institutional case series of 102 consecutive patients diagnosed with unilateral iERMs were recruited at Peking University Third Hospital and were followed up for 12 months after surgical treatment with vitrectomy. Participants were classified into four stages according to current staging scheme. All eligible subjects underwent standardized imaging evaluation of choroidal parameters including subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), and choroidal capillary perfusion (CCP) at baseline and each follow-up by enhanced depth optical coherence tomography (EDI-OCT) and OCT angiography (OCTA). Longitudinal follow-up of choroidal parameters over 12 months was analysed, and their correlations with best-corrected visual acuity (BCVA) were also assessed for predictive prognostic value. RESULTS: CVI and CCP were significantly correlated with BCVA at each follow-up examination (all p < 0.05). However, SFCT exhibited no variation among different stages of iERMs at baseline (p = 0.981) or during follow-up (p = 0.520). The preoperative CVI correlated with 12-month postoperative BCVA (p < 0.001) and its predictive prognostic effect on BCVA was validated in multiple regression analysis (p = 0.006). CONCLUSION: CVI varied among different stages of iERM and was significantly correlated with visual outcomes after the surgery. CVI could serve as a predictive prognostic marker in iERMs, which further indicates the underlying choroid should be taken into consideration in clinical evaluation of iERMs.

Changes in peripapillary choroidal thickness within one year of the first episode of acute primary angle closure glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the changes in peripapillary choroidal thickness(pCT)within 1a of the first episode of acute primary angle closure glaucoma(APACG).METHODS: A prospective cohort study. A total of 31 patients with APACG who admitted to the ophthalmology department of Shijiazhuang People's Hospital from October 2015 to September 2019 were selected, with 31 eyes in attack group, 31 fellow eyes in preclinical group and 30 cases(30 eyes)in control group. pCT of the three groups was measured respectively at the attack period, 1wk, 1, 3, 6mo and 1a after surgery.RESULTS: The pCT of the attack group was thicker than that in the attack period when at 1wk after surgery, and continued to become thinner within the following 1a(P&#x0026;#x003C;0.05). The pCT of the attack group was thicker than that of the other two groups during the attack period and at 1wk after surgery, while it became thinner at 1a(P&#x0026;#x003C;0.05). In the attack group, the average pCT was positively correlated with the duration of intraocular hypertension and negatively correlated with the anterior chamber depth(P&#x0026;#x003C;0.05).CONCLUSION: For patients with first episode of APACG, pCT was diffusely thickened during attack and at 1wk after surgery. The pCT returned to normal at 1mo, while it became thinner at 1a. Furthermore, the average pCT was positively correlated with the duration of intraocular hypertension, and the choroidal thickness may play an important role in the attack of APACG.

Research progress on the application of deep learning in choroidal segmentation / 国际眼科杂志(Guoji Yanke Zazhi)

In recent years, ophthalmology, as one of the medical fields highly dependent on auxiliary imaging, has been at the forefront of the application of deep learning algorithm. The morphological changes of the choroid are closely related to the occurrence, development, treatment and prognosis of fundus diseases. The rapid development of optical coherence tomography has greatly promoted the accurate analysis of choroidal morphology and structure. Choroidal segmentation and related analysis are crucial for determining the pathogenesis and treatment strategies of eye diseases. However, currently, choroidal mainly relies on tedious, time-consuming, and low-reproducibility manual segmentation. To overcome these difficulties, deep learning methods for choroidal segmentation have been developed in recent years, greatly improving the accuracy and efficiency of choroidal segmentation. The purpose of this paper is to review the features of choroidal thickness in different eye diseases, explore the latest applications and advantages of deep learning models in measuring choroidal thickness, and focus on the challenges faced by deep learning models.

Choroidal and retinal thickness variations in ocular albinism.

Purpose: To study the retinal and choroidal thickness variations on enhanced depth imaging optical coherence tomography scans in ocular albinism (OA) and compare with age-matched healthy subjects. Methods: This retrospective observational study had 48 eyes of 24 patients diagnosed clinically as OA and age, sex, and axial length-matched control healthy subjects. All patients underwent detailed ophthalmic examination and a single-line horizontal-raster enhanced depth imaging - optical coherence tomography scan (Spectralis, Heidelberg Engineering). Retinal and choroidal thickness was measured, compared, and analyzed between the two groups. Mann-Whitney U test was used for analysis between the two groups. P < 0.05 was considered significant. Results: The mean age was 28.3 ± 11.6 and 29.9 ± 10.6 years in the OA group and control group, respectively. Spherical equivalents ranged from -8.5D to +10.5D in the OA group and from -8.0D to +10.0D in the control group. The mean axial length between the two groups (P = 0.652) were comparable. The average retinal thickness (272 ± 34.3 vs. 213 ± 13.8 µm; P < 0.001) was greater in the OA group as compared to controls. The mean choroidal thickness (184 ± 78.4 vs. 287 ± 46.4 µm; P < 0.001) was significantly thinner in the OA group. Conclusion: Acquisition of OCT scans in OA can be challenging. This study showed that the subfoveal retinal thickness and choroidal thickness measured across the scans were significantly different in the OA group compared to controls. In the future, more studies are required to evaluate the role of the choroid and its relationship to emmetropization in albinism.

How does anisometropia affect the choroidal vascularity index?

Purpose: To investigate the choroidal vascularity index (CVI) and morphological features of the choroid in anisometropic amblyopia. Methods: In this prospective cross-sectional study, 39 patients with unilateral anisometropic amblyopic patients and 33 eyes of 33 healthy control participants were involved. These participants were examined in terms of axial length (AL), spherical equivalent (SE), central macular thickness (CMT), choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), LA/SA ratio, and CVI. All parameters were compared between amblyopic eyes, healthy fellow eyes, and healthy control eyes. The Shapiro-Wilk tests, Chi-square test, the paired t-test, Wilcoxon signed-rank test, Mann-Whitney U test, Kruskal-Wallis test, and Pearson/Spearman correlation tests were used. Results: In the hyperopic patients; SE, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA, and CMT were greater in amblyopic eyes than in healthy fellow eyes and control eyes (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively), and CVI, LA/SA ratio, and AL were smaller in amblyopic eyes than in healthy fellow eyes and control eyes ([P < 0.001, P = 0.006], P < 0.001, and P < 0.001, respectively). In the myopic patients, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA values were statistically smaller in amblyopic eyes than in healthy eyes and control eyes ([P < 0.001, P = 0.002), [P = 0.004, P = 0.012], [P = 0.012, P = 0.032], [P < 0.001, P = 0.013], [P < 0.001, P = 0.024], and [P < 0.001, P = 0.047], respectively). The differences in the AL and choroidal parameters were due to myopia and hyperopia. Conclusion: The choroidal structural parameters of the amblyopic eyes were different from that of the healthy eyes.

Choroidal Thickness in Emmetropia: An Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography-Based Study.

Objectives: To investigate and determine the choroidal thickness (CT) in healthy emmetropic Turkish subjects aged between 20 and 40 years using Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography (EDI-OCT). Methods: This study included 194 eyes of 194 healthy emmetropic subjects. All participants underwent a detailed ophthalmologic examination. Axial length (AL) was measured with optical biometry. CT measurements were performed at subfoveal, 1.0 mm temporal, and 1.0 mm nasal using the EDI-OCT. Central macular thickness (CMT) measurements were also performed at the same time. Participants were divided into two groups; Group 1 (age between 20 and 30 years) and Group 2 (age between 31 and 40 years). CT and CMT were compared among two groups. Results: The mean age of all the subjects was 26.61±6.08 years, the mean AL was 23.44±0.72 mm, and the mean spherical equivalent was -0.11±0.28 Diopter. The mean subfoveal, nasal, and temporal CT was 389.27±86.61 µm, 354.54±86.86 µm, and 368.25±78.69 µm, respectively. Subfoveal and nasal CT of female participants were found thinner than male participants (p=0.013 and p=0.008, respectively). CT and CMT were found similar between Group 1 and Group 2. Conclusion: This study showed that mean subfoveal CT and CMT was 389.27±86.61µm and 268.17±18.76 µm, respectively, among healthy emmetropic Turkish subjects. Females had thinner CT in subfoveal and nasal quadrants. In addition, age did not affect CT between 20 and 40 years.

Disc-fovea distance and choroidal thickness: is there a relationship?

Background: The distance between the optic disc center and the fovea is a biometric parameter; however, it is unclear whether DFD (disc-fovea distance) affects the choroidal thickness. Objective: The aim of this study is to investigate the association between DFD and choroidal thickness. Design: This is a prospective, and cross-sectional study. Methods: Two hundred fifty eyes of 250 healthy participants were examined in terms of DFD, age, axial length, spherical equivalent, and choroidal thickness. Inclusion criteria included aged between 20-40 years, no posterior segment disorders, and participants with best-corrected visual acuity (10/10 according to Snellen's chart). Participants with high hypermetropia (>4 diopter) or myopia (>6 diopter) or any systemic disease likely to affect choroidal thickness were excluded. Choroidal thickness measurements were performed at subfoveal, 1.0 mm temporal, and 1.0 mm nasal using the enhanced-depth imaging optical coherence tomography. Results: The mean age of all the participants was 26.21 ± 5.73 years, mean DFD was 4634.29 ± 274.70 µm, mean axial length was 23.62 ± 0.83 mm, and mean spherical equivalent was -0.61 ± 1.06 diopter. The mean subfoveal, nasal, and temporal choroidal thicknesses were 388.73 ± 90.15 µm, 351.26 ± 88.09 µm, and 366.50 ± 79.56 µm, respectively. A negative correlation was found between subfoveal, nasal, and temporal choroidal thicknesses and axial length (r = -0.157, p = 0.013; r = -0.168, p = 0.008; r = -0.174, p = 0.006, respectively). Insignificant correlation was found between choroidal thicknesses and spherical equivalent (p > 0.05). There was not a statistically significant correlation between DFD and subfoveal, nasal, and temporal choroidal thicknesses (r = -0.028, p = 0.655; r = 0.030, p = 0.641; r = -0.025, p = 0.699, respectively). In addition, there was not a statistically significant correlation between age and choroidal thickness. Conclusion: This study shows that DFD and spherical equivalent do not affect choroidal thickness; axial length negatively affects choroidal thickness. In addition, age does not affect choroidal thickness between 20 and 40 years.

Choroidal structural alterations in diabetic patients in association with disease duration, HbA1c level, and presence of retinopathy.

PURPOSE: To assess choroidal structural changes in diabetic patients in association with disease duration, HbA1c level, and presence of retinopathy. METHODS: This retrospective cross-sectional study included treatment-naive patients with non-proliferative DR (NPDR) (group 1), diabetic patients without DR (group 2), and healthy subjects (group 3). Patients were also grouped according to the duration of diabetes: long-term group (> 15 years, n = 32) and short-term group (˂ 15 years, n = 28). The choroidal thickness was measured at three points; subfoveal, 1500 µm nasal, and 1500 µm temporal to the fovea. The choroidal area, stromal area, luminal area (LA), and choroidal vascularity index (CVI) were quantified using ImageJ. Partial correlation analysis and one-way analysis of covariance test were performed for statistical analysis. RESULTS: The study included 30 eyes of 30 treatment-naive patients with NPDR (group 1), 30 eyes of 30 diabetic patients without DR (group 2), and 30 eyes of 30 healthy persons (group 3). The mean subfoveal, nasal, and temporal choroidal thicknesses were decreased in group 1 in comparison with controls (p < 0.001, p = 0.035, and p = 0.005, respectively). The mean LA in group 1 and group 2 were both significantly lower compared to group 3 (group 1 vs. group 3, p = 0.004; group 2 vs. group 3, p = 0.020). CVI was significantly lower in group 1 and group 2 than in controls (group 1 vs. group 3, p = 0.019; group 2 vs. group 3, p = 0.025). CVI was significantly lower in the long-duration group than in the short-duration group (p < 0.001). A moderate negative correlation was found between the duration of diabetes and CVI (r = - 0.467, p < 0.001). A moderate negative correlation was found between HbA1c level and luminal area and CVI (r = - 0.466, p < 0.001, and r = - 0.425, p < 0.001, respectively). CONCLUSION: Choroidal structure and CVI are altered even in the absence of clinically confirmed retinopathy and these alterations are related to the duration of diabetes.

Comparison of Choroidal Thickness, Foveal Avascular Zone, and Macular Capillary Density in Macular Edema Secondary to Branch Retinal Vein Occlusion Treated with Ranibizumab or Aflibercept-A Prospective Study.

This prospective comparative case series aims to compare best-corrected visual acuity (BCVA), retinal microvasculature, and retinal structural changes in patients treated with either ranibizumab or aflibercept for macular edema (ME) secondary to treatment-naïve branch retinal vein occlusion (BRVO) by optical coherence tomography angiography (OCTA). Ten patients were enrolled with macular capillary density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) and foveal avascular zone (FAZ) measured in both eyes before and after treatment. Final central retinal thickness and BCVA improved significantly (p < 0.05), and densities of SCP and DCP of BRVO sectors were significantly lower at baseline than fellow eye counterparts and remained persistently lower during treatment, particularly in the aflibercept group (p < 0.05). SCP density, DCP density of both BRVO sectors (p = 0.0001, p < 0.0001), and non-BRVO sectors (p < 0.0001, p < 0.0001) were significantly correlated with final BCVA for diseased eyes. Using multivariate general linear model analysis, and including OCTA parameters only, but not all of the available clinical data, DCP density of BRVO sectors in both eyes was the most predictive factor for final visual outcome (probability p < 0.0001). OCTA offered further qualitative and quantitative evaluation of treatment-naïve BRVO. Judging by OCTA parameters, not only in the diseased eye but also in the fellow eye, DCP density of BRVO sectors was the most predictive factor of final visual outcome.

CVIS: Automated OCT-scan-based software application for the measurements of choroidal vascularity index and choroidal thickness.

PURPOSE: To develop an automated image recognition software for the objective quantification of choroidal vascularity index (CVI) and choroidal thickness (CT) at different choroidal locations on images obtained from enhanced depth imaging optical coherence tomography (EDI-OCT), and to validate its reliability and investigate the difference and correlation between measurements made by manual and software. METHODS: A total of 390 EDI-OCT scans, captured from 130 eligible emmetropic or myopic subjects, were categorized into four grades in terms of their accessibility to identify the choroidal-scleral interface (CSI) and were further assessed for CT and CVI at five locations (subfoveal, nasal, temporal, superior and inferior) by the newly developed Choroidal Vascularity Index Software (CVIS) and three ophthalmologists. Choroidal parameters acquired from CVIS were evaluated for its reliability and correlation with ocular factors, in comparison to manual measurements. Distribution of difference and correlation coefficient between CVIS and manual measurements were also analysed. RESULTS: Choroidal Vascularity Index Software (CVIS) demonstrated excellent intra-session reliability for CT (ICC: 0.992) and CVI (ICC: 0.978) measurements, compared to the relatively lower intra- and inter-observer reliability of manual measurements. Choroidal Vascularity Index Software (CVIS) and manual assessments had the highest correlation at nasal choroid (CT: r = 0.829, p < 0.001; CVI: r = 0.665, p < 0.001). Choroidal parameters identified with CVIS showed stronger correlations with axial length than manual measurements. CONCLUSION: This automated software, CVIS, exhibited excellent reliability compared to manual measurements, which are subject to image quality and clinical experience. With its validated clinical relevance, CVIS holds promise to serve as a flexible and robust tool in future vitreoretinal and chorioretinal studies.