Enhanced Depth Imaging Optical Coherence Research Articles

The relationship between reduced choroidal thickness due to high plasma asymmetrical dimethylarginine level and increased severity of diabetic retinopathy.

To evaluate the relationship between subfoveal choroidal thickness and plasma asymmetrical dimethylarginine level and the severity of diabetic retinopathy in patients with type 2 diabetes mellitus. A total of 68 cases, including 15 patients without diabetic retinopathy, 17 patients with nonproliferative diabetic retinopathy, 16 patients with type 2 diabetes mellitus and proliferative diabetic retinopathy, and 20 healthy patients (control group), were enrolled in this study. Subfoveal choroidal thickness was measured manually using the enhanced depth imaging optical coherence tomography scanning program, and plasma asymmetrical dimethylarginine level was measured using a commercial micro enzyme-linked immunosorbent assay kit. The subfoveal choroidal thickness values and plasma asymmetrical dimethylarginine levels were significantly different between the four groups (p<0.001 and p<0.001). The subfoveal choroidal thickness values were significantly lower in the proliferative diabetic retinopathy group than in the other three groups (no diabetic retinopathy, nonproliferative diabetic retinopathy, and control groups; p<0.001, p=0.045, and p<0.001, respectively). The plasma asymmetrical dimethylarginine levels were significantly higher in the proliferative diabetic retinopathy group than in the other three groups (p<0.001, p<0.04, and p<0.001, respectively). In addition, a significant negative correlation was also found between plasma asymmetrical dimethylarginine level and subfoveal choroidal thickness (p<0.001, r=-0.479). Asymmetrical dimethylarginine is an important marker of endothelial dysfunction and endogenous endothelial nitric oxide synthase inhibitor. The severity of diabetic retinopathy was related to increased plasma asymmetrical dimethylarginine level and reduced subfoveal choroidal thickness in type 2 diabetic patients with diabetic retinopathy.

Farklı Beden Kitle İndeksi Gruplarında Koroid Vaskülarite İndeksi Değişiklikleri: Olgu Kontrol Çalışması

Objective: Comparing Choroidal Vascularity Index (CVI) values in groups with different body mass index (BMIs). Material and Methods: In this prospective study, we compared choroidal thickness (CT) and CVI values of those with different BMI. The weight and height of all patients were measured, and BMI was calculated. All volunteers were examined with a detailed eye examination. In addition, enhanced depth imaging optical coherence tomography (EDI-OCT) of all individuals was evaluated. Results: The study included 157 right eyes of 157 volunteers. Of these, 30 were normal, 30 were overweight, 30 were class 1 obese, 22 were class 2 obese, and 45 were morbidly obese. CVI and CT of all groups were compared with EDI-OCT. There was a statistically significant difference in CT between the groups in the temporal CT 500 μm, temporal CT 1,000 μm, temporal CT 1,500 μm, and nasal CT 500 μm regions (p<0.005). The CVI and luminal area/stromal area (LA/SA) groups also found a statistically significant difference (p<0.005). In the correlation analysis with BMI, a statistically significant weak negative correlation was found between BMI, CVI, and LA/SA (r=-0.304, p<0.001 and r=-0.255, p=0.001, respectively). In addition, a positive correlation was found between BMI in temporal CT 500 μm, temporal CT 1,000 μm and temporal CT 1,500 μm and nasal CT 1,000 μm and nasal CT 1,500 μm measurements. Conclusion: There is a negative correlation between BMI and CVI. In addition, a statistically significant difference was found between the morbidly obese group and the normal weight BMI groups regarding choroidal structures.

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

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). 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. 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. It seems that CVI as well as other choroidal biomarkers were not significantly different between patients with KCN and healthy subjects.

How does Covid-19 affect the choroidal structures at the early post-infectious period?

To evaluate choroidal thickness (CT) and choroidal vascularity index (CVI) in patients recovered from COVID-19 using enhanced depth imaging optical coherence tomography in the early postinfectious period. Sixty-five patients recovered from COVID-19 and 72 healthy subjects were included in the study. A full ophthalmic examination including best-corrected visual acuity (BCVA), slit lamp biomicroscopy, and dilated fundus examination was performed. CT was measured at 3 points as follows: subfoveal, 1000μm nasal and temporal to the fovea. The total choroidal area (TCA), luminal area (LA), stromal area (SA), and CVI were measured with Image-J. The mean age was 39.09±11.27 years in the COVID-19 group and 39.61±11.43 years in the control group. The mean time from the first positive RT-PCR was 49.54±26.82 days (range 18-120) in the COVID-19 group. No statistically significant difference was detected between the groups with regard to axial length, spherical equivalent, and BCVA (all P>0.05). CT was found to be lower in the COVID-19 group compared to the control group in all quadrants, but this difference was not significant (all P>0.05). The mean TCA, LA, and CVI were statistically significantly reduced in the COVID-19 group (all P<0.001); however, SA showed no statistically significant difference (P=0.064). In asymptomatic or mild COVID-19, CVI and LA decrease significantly, while CT thins in the early postinfectious period but not significantly.

The choroid vascular index and its association with visual acuity in children and young adults with high myopia.

To explore the relationship between the choroid vascular index (CVI) and best corrected visual acuity (BCVA) in a young population with high myopia (HM). Three hundred twenty-six patients with HM were recruited. All subjects underwent a comprehensive ophthalmic examination and enhanced depth imaging optical coherence tomography (EDI-OCT). The horizontal and vertical subfoveal choroidal areas within a 3-mm diameter centred over the fovea were selected. Choroid thickness (ChT), horizontal and vertical total choroidal area (TCAH and TCAV), luminal area (LAH and LAV) and stromal area (SAH and SAV) within the 3-mm diameter were assessed. CVI values (CVIH and CVIV), defined as the ratio of LA to TCA, were also calculated. The correlations among choroid parameters and ocular characteristics were analysed. The median age, spherical equivalent (SE) and BCVA were 22.4 years, -10.1 dioptres and 0.099 logMAR, respectively. The ChT was thickest on the temporal and superior sides of the macula and thinnest in the nasal region, with a significant difference. The value of CVIH was significantly greater than that of CVIV because SCAH was smaller than SCAV. Both CVIH and CVIV were closely correlated with BCVA in all patients. The CVI is significantly related to BCVA but is not affected by age, axial length or SE, suggesting that the CVI could be used as an adjunct tool for assessing the visual acuity status in patients with HM.

A Comparison of Diagnostic Accuracy of Imaging Modalities to Detect Optic Disc Drusen: The Age of Enhanced Depth Imaging Optical Coherence Tomography

To identify the most accurate diagnostic imaging modality to detect optic disc drusen (ODD) between B-scan ultrasonography (US), fundus photography, fundus autofluorescence (FAF), and enhanced depth imaging optical coherence tomography (EDI-OCT). Comparative diagnostic analysis. Two hundred five eyes of 105 patients referred to 2 tertiary care neuro-ophthalmology clinics for suspected ODD were recruited: 108 eyes had ODD and 97 did not have ODD. All eyes received a full in-person ophthalmic exam with 3D view of the optic nerve and all 4 imaging modalities. Images were independently reviewed by 3 masked neuro-ophthalmologists to determine the presence or absence of ODD. Final interpretation was made through consensus. The reference standard was defined as the attending ophthalmologist's clinical judgement based on open chart review, with access to all image modalities and clinical information, including disease course. Main outcome measures were sensitivity, specificity, accuracy, and precision for each imaging modality. Examiner confidence was quantified as the proportion of eyes in which the reviewers were certain of their decision. The EDI-OCT had the highest sensitivity and accuracy (95%, 97%) to detect ODD, compared with FAF (84%, 92%), US (74%, 86%), and fundus photography (38%, 66%), respectively. All image modalities had high specificity (> 97%) and precision (> 93%). The EDI-OCT also had highest examiner confidence (96%) compared with all others (88%). Among all modalities, EDI-OCT was the imaging modality with the highest diagnostic utility for the detection of ODD and should be considered as the preferred initial diagnostic modality.

Multimodal Imaging of Severe Oxalate Retinopathy in a 20-Month-Old Boy

Primary hyperoxaluria type 1 (PH1) is a rare disease due to alanine glyoxylate aminotransferase enzyme deficiency caused by mutations in AGXT gene. Increased oxalate causes crystalline deposits in the eye particularly in conjunctiva, cornea, iris, retina, and choroid. A 20-month-old boy was referred with a diagnosis of infantile PH1. There were numerous yellowish crystalline deposits at the posterior pole and hyperpigmented lesions were detected around the macula. Enhanced depth imaging optical coherence tomography (EDI-OCT) revealed dome-shaped retinal pigment epithelium elevations, subretinal and intraretinal hyperreflective material and also choroidal hyperreflective lesions. To the best of our knowledge, this is the first case to document choroidal deposition by EDI-OCT at such an early period of life. [Ophthalmic Surg Lasers Imaging Retina 2022;53:697-700.].

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

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). 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. 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). 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.

Optic disc drusen in patients diagnosed with normal tension glaucoma.

To investigate the prevalence of optic disc drusen (ODD) and optic nerve head (ONH) morphology in patients diagnosed with normal tension glaucoma (NTG). In this prospective cross-sectional study, we included patients diagnosed with NTG from two glaucoma units. In both eyes, dense enhanced depth imaging optical coherence tomography volume scans of the ONH by means of standardized scanning guidelines were performed to examine for presence of ODD, and radial ONH scans were used for investigating parameters such as scleral canal diameter, cup/disc ratio and cup depth. We found ODD in 7 (3.6%) of 195 eyes, in 6 (6.1%) out of 98 patients diagnosed with NTG. The ODD were not ophthalmoscopically visible in five out of six patients. Eyes with ODD had lower cup/disc ratio, 0.44±0.4 (p=0.040), and less-prominent cup depth, 236.6±204.4μm (p=0.041) compared to eyes without ODD, 0.81±0.2 and 437.8±139.1μm, respectively. We found no significant difference in scleral canal diameter between the eyes without (1602.8±193μm) and those with ODD (1492±123.4μm, p=0.057). The prevalence of ODD in patients diagnosed with NTG is substantially higher than in the background population. A low cup/disc ratio correlates with ODD presence. Therefore, due to the challenges associated with NTG diagnosis, we recommend examining the deep layers of the ONH in NTG patients with a cup/disc ratio lower than 0.5 to avoid misdiagnosing ODD as NTG.

LONGITUDINAL ASSESSMENT OF CHOROIDAL STRUCTURE IN PATIENTS WITH MACULAR NEOVASCULARIZATION.

To investigate morphologic changes of choroidal structure through chronologic aspect in progression of macular neovascularization (MNV) with pachychoroid features. One hundred seventy-one MNV participants above 50 years old with or without pachychoroid features were included in the analysis. Age-matched 132 normal patients were analyzed as control group. The total choroidal area and ratio of Sattler's layer area to total choroidal area, derived by summing 25 horizontal raster scans of the 30° × 20° scan area on enhanced depth imaging optical coherence tomography, were calculated to compare the difference among the normal eyes and the MNV eyes with/without pachychoroid features. The mean ratio of Sattler's layer area to total choroidal area is maintained at around 40% in normal eyes and MNV eyes without pachychoroid features. In MNV with pachychoroid features, the ratio of Sattler's layer area to total choroidal area changes according to the disease activity. Ratio of Sattler's layer area to total choroidal area is 34.1 ± 4.4% at the time of onset, 37.2 ± 4.8% at the time of remission, and decreases during recurrence from 36.8 ± 3.8% to 33.4 ± 3.8% (all P < 0.001). MNV with pachychoroid features is a disease whose development and progression are related to a change in the choroidal interlayer area ratio following the relatively larger dilation of Haller's layer vessels.

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.

Differentiating a pachychoroid and healthy choroid using an unsupervised machine learning approach

The purpose of this study was to introduce a new machine learning approach for differentiation of a pachychoroid from a healthy choroid based on enhanced depth-optical coherence tomography (EDI-OCT) imaging. This study included EDI-OCT images of 103 eyes from 82 patients with central serous chorioretinopathy or pachychoroid pigment epitheliopathy, and 103 eyes from 103 age- and sex-matched healthy subjects. Choroidal features including choroidal thickness (CT), choroidal area (CA), Haller layer thickness (HT), Sattler-choriocapillaris thickness (SCT), and the choroidal vascular index (CVI) were extracted. The Haller ratio (HR) was obtained by dividing HT by CT. Multivariate TwoStep cluster analysis was performed with a preset number of two clusters based on a combination of different choroidal features. Clinical criteria were developed based on the results of the cluster analysis, and two independent skilled retina specialists graded a separate testing dataset based on the new clinical criteria. TwoStep cluster analysis achieved a sensitivity of 1.000 (95-CI: 0.938–1.000) and a specificity of 0.986 (95-CI: 0.919–1.000) in the differentiation of pachy- and healthy choroid. The best result for identification of pachychoroid was obtained for a combination of CT, HR, and CVI, with a correct classification rate of 0.993 (95-CI: 0.980–1.000). Based on the relative variable importance (RVI), the cluster analysis prioritized the choroidal features as follows: HR (RVI: 1.0), CVI (RVI: 0.87), CT (RVI: 0.70), CA (RVI: 0.59), and SCT (RVI: 0.27). After performing a receiver operating characteristic curve analysis on the cluster membership variable, a cutoff point of 389 µm and 0.79 was determined for CT and HR, respectively. Based on these clinical criteria, a sensitivity of 0.793 (95-CI: 0.611–0.904) and a specificity of 0.786 (95-CI: 0.600–0.900) and 0.821 (95-CI: 0.638–0.924) were achieved for each grader. Cohen's kappa of inter-rater reliability was 0.895. Based on an unsupervised machine learning approach, a combination of the Haller ratio and choroidal thickness is the most valuable factor in the differentiation of pachy- and healthy choroids in a clinical setting.

Peripapillary hyperreflective ovoid masslike structures (PHOMS) in a pediatric population referred for suspected papilledema

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are a new, benign entity identified in evaluation of the optic nerve, best described on enhanced depth imaging optical coherence tomography (EDI-OCT). PHOMS are now being considered the most common cause for pseudopapilledema in children. We chose to investigate pediatric patients with PHOMS referred for suspected papilledema.

Superficial Retinal Microvasculature and Choriocapillaris Alterations after Photodynamic Therapy in Chronic Central Serous Chorioretinopathy.

Purpose To compare superficial retinal vascular, choriocapillaris (CC), and choroidal thickness changes in chronic central serous chorioretinopathy (CSCR) patients after half-dose photodynamic therapy (PDT). Method In this prospective interventional case series study, fifteen eyes of 14 patients with chronic CSCR undergoing half-dose PDT treatment were enrolled. All patients underwent enhanced depth imaging optical coherence tomography angiography (EDI-OCT) and optical coherence tomography angiography (OCTA) at baseline and 3 months after treatment. Best-corrected visual acuity (BCVA), superficial retinal vascular density, CC vessel density, foveal avascular zone (FAZ), central macular thickness (CMT), and choroidal thickness were compared. Results Mean BCVA before and after PDT was 0.34 ± 0.26 and 0.19 ± 0.25 logMAR, respectively (p=0.011). Mean FAZ before treatment was 410.21 ± 117.00 μm2, which increased to 433.50 ± 116.76 μm2 (P=0.253). Mean vessel density at superficial capillary plexus (SCP) was 38.93 ± 11.12 at baseline, which increased to 39.04 ± 11.43 (P=0.886). Mean CC vessel density was 53.21 ± 4.14 at baseline, which significantly decreased to 51.85 ± 4.21 (P=<0.001). BCVA has no significant correlation with FAZ (P=0.282) and vessel density (P=0.0.241) at SCP. CMT significantly decreased from 380.87 ± 41.66 μ at baseline to 268.20 ± 28.07 μ at 3 months (P=0.132). We did not find any correlation between CMT and FAZ (P=0.040) and vessel density (P=0.686) at SCP. Mean subfoveal choroidal thickness reduced from 411 ± 171 μm before treatment to 372 ± 117 μm (P=0.106). Conclusion PDT treatment can affect retinal and choroidal structural parameters, but we could not find any significant influence on retinal vascular parameters, including FAZ area and vessel densityonly mean CC vessel density and subfoveal choroidal thickness decreased.

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.

Choroidal structural evaluation in inactive Graves’ ophthalmopathy

PurposeTo investigate the changes in the choroidal structure in patients with inactive Graves Ophthalmopathy (GO). DesignA prospective, masked, observational cross-sectional study. MethodsChanges in choroidal vascularity index (CVI) were studied in the patients with inactive GO using binarization on enhanced depth imaging optical coherence tomography (EDI-OCT) images. Choroidal area, subfoveal choroidal thickness (SFCT), stromal area, luminal area, CVI and retinal nerve fiber layer (RNFL) thickness was used to compare the eyes of sixty-four age-, gender-matched healthy subjects. All measurements were done separately both subfoveal (1500 µm) and total choroidal area (7500 µm). The relation between CVI or SFCT and age, gender, duration of disease, the severity of disease, TRAb (thyrotropin receptor autoantibody), smoking status, and exophthalmometer readings were evaluated. ResultsThere were 56 patients (30 female, 26 male; mean age: 39.5 ± 11.4 years) in the GO group and 64 patients (34 female, 30 male; mean age: 42.2 ± 5.6 years) in the healthy subject group. There was no statistically significant difference between subjects with GO and healthy controls regarding age (p = 0.24) and gender distribution (p = 0.55). Patients with GO had significantly higher intraocular pressure (p = 0.001) and exophthalmometer readings (p = 0.0001) than the healthy controls. The SFCT, CVI1500 and the stromal area1500 was significantly different between the groups (p = 0.009, p = 0.009, p = 0.011, respectively). Multivariate analysis showed that age (-0.871, p = 0.02) was highly correlated with the decreased SFCT, and duration of disease (0.524, p = 0.001) was significantly positively correlated with SFCT. Luminal area1500 (-0.416, p = 0.0001)and stromal area1500 (-0.657, p = 0.0001) were significantly negatively correlated with CVI1500 in the patients with GO. ConclusionAlthough higher CVI1500 was observed in GO patients than in healthy controls, the degree of increase was not the same in the CVI7500. Age and duration of disease significantly affect the SFCT, and luminal area1500 and stromal area1500 significantly affect the CVI1500.

Peripapillary Vessel Density in Relation to Optic Disc Drusen: A Multimodal Optical Coherence Tomography Study.

Optic disc drusen (ODD) are acellular calcified deposits within the optic nerve head known to cause visual field defects. An emerging gold standard for the diagnosis of ODD is enhanced depth imaging optical coherence tomography (EDI-OCT). The presence of ODD affects the adjacent peripapillary vasculature, which can be visualized using OCT angiography (OCTA). This study investigates the association between peripapillary vessel density and anatomical ODD location and volume using a newly developed method of multimodal OCT. A case-control study with 16 patients diagnosed with ODD in the period 2008-2017 and 24 healthy controls. All patients and controls had EDI-OCT, OCTA, and demographic data collected. Using EDI-OCT and the medical imaging segmentation tool ITK-SNAP, 3-dimensional (3D) visualization of ODD in patients were created. ODD 3D visualization and corresponding OCTA scans were superimposed, making it possible to correlate ODD volume to the peripapillary vessel density in the corresponding modified Garway-Heath segments of the optic disc. We found that mean peripapillary vessel density across all modified Garway-Heath segments were lower in ODD patients compared with controls with significant reduction of peripapillary vessel density in the superior segment ( P = 0.03) and globally ( P = 0.05). A significant inverse proportionality between ODD volume and peripapillary vessel density in the corresponding segment was seen ( P = 0.002). We found a reduced peripapillary vessel density in regions with close anatomical proximity to ODD and inverse proportionality between ODD volume and peripapillary vessel density.

Choroidal vascularity index after a single dose of intravitreal dexamethasone implant in patients with refractory diabetic macular oedema

PurposeTo evaluate choroidal vascularity index (CVI) after a single dose of intravitreal dexamethasone implant in refractory diabetic macular oedema (DME). MethodsTotal choroidal area, luminal area, and CVI were measured at baseline, 1st month, and at 3rd month after dexamethasone implant using binarization of enhanced depth imaging optical coherence tomography (EDI-OCT) images. ResultsA total of 25 eyes of 25 patients (mean age: 61.4 ± 8.3 years; 12 males, 13 females), were enroled in the study. All eyes had been previously treated with intravitreal aflibercept injections (mean number of injections 4.6 ± 2.5). Mean CVI was 70.3 ± 8.1 prior to intravitreal dexamethasone treatment. It was decreased to 66.1 ± 9.3 at 1 month and 63.5 ± 10.1 at 3 months after treatment. The mean CVI was significantly decreased at 3 months compared with pre-treatment measures (p = 0.033). ConclusionCVI was found to be decreased in patients who responded to intravitreal dexamethasone implant.

REGIONAL SCLERAL THICKNESS AS A RISK FACTOR FOR CENTRAL SEROUS CHORIORETINOPATHY.

To evaluate regional sclera thicknesses as possible risk factors for central serous chorioretinopathy (CSC). Patients with CSC and controls were evaluated with contact B-scan ultrasonography using a 20 Mhz concentric phased array ultrasound unit and enhanced depth imaging optical coherence tomography to measure the scleral thickness at the equator and posterior pole. The resultant data were evaluated using univariate analysis and generalized estimating equations. There were 40 patients with CSC with a mean age of 58 years and 23 controls with a mean age of 60.7 years (P = 0.31). The mean subfoveal scleral thicknesses were 1.3 mm in the CSC group and 0.86 mm in the control group (P < 0.001). The mean equatorial scleral thickness was 0.61 mm in the CSC group and 0.42 mm in the control group (P < 0.001). Using generalized estimating equations, the equatorial scleral thickness (P = 0.001), posterior scleral thickness (P < 0.001), and subfoveal choroidal thickness (P = 0.032) were independent predictors of CSC. Once these variables were entered into the equation, neither sex nor age were significant predictors. Generalized estimating equation analysis showed that equatorial, but not posterior, scleral thickness was a significant predictor of subfoveal choroidal thickness. Scleral thicknesses of the posterior and equatorial portions of the eye were found to be significant predictors of CSC, consistent with what was proposed in the theory of venous overload choroidopathy. Direct measurement by high resolution ultrasonography provides independent information about specific regions of the sclera and also avoids making speculative assumptions derived from anterior segment measurements.

Evaluation of Choroidal Thickness during Pregnancy and Postpartum: A Longitudinal Study.

To assess the longitudinal changes of choroidal thickness using enhanced depth imaging optical coherence tomography (EDI-OCT) during pregnancy and postpartum. The study included 23 eyes of 23 healthy pregnant women and 23 eyes of 23 healthy nonpregnant women. Choroidal thickness was measured manually with EDI-OCT at seven locations: The fovea, 500, 1000, and 1500 μm temporal (T) from the fovea and 500, 1000, and 1500 μm nasal (N) from the fovea. Measurements were obtained at each pregnancy trimester and 6 weeks postpartum and in the follicular phase of the menstrual cycle for the control group. The mean subfoveal choroidal thickness was 410.2 ± 82.4 μm, 434.8 ± 79.6 μm, 433.5 ± 80.3 μm, and 395.0 ± 71.1 μm in the first, second, and third trimesters and 6 weeks postpartum, respectively. In all seven measured locations, statistically significant changes were noted during pregnancy and postpartum in the choroidal thickness (P < 0.001). Choroidal thickness increased from the first trimester to the second and third trimester, after which it decreased at postpartum. Choroidal thickness was greater in the pregnant group during pregnancy and postpartum compared to the control group (P < 0.001). This study indicated significant change in choroidal thickness at seven locations measured with EDI-OCT throughout pregnancy and 6 weeks after delivery. We showed that 6 weeks after delivery, choroidal thickness remains significantly higher than nonpregnant subjects.