Optical Coherence Tomography Angiography Findings Research Articles

Optical Coherence Tomography Angiography in Diabetic Patients: A Systematic Review.

Background: Diabetic retinopathy (DR) is the leading cause of legal blindness in the working population in developed countries. Optical coherence tomography (OCT) angiography (OCTA) has risen as an essential tool in the diagnosis and control of diabetic patients, with and without DR, allowing visualisation of the retinal and choroidal microvasculature, their qualitative and quantitative changes, the progression of vascular disease, quantification of ischaemic areas, and the detection of preclinical changes. The aim of this article is to analyse the current applications of OCTA and provide an updated overview of them in the evaluation of DR. Methods: A systematic literature search was performed in PubMed and Embase, including the keywords “OCTA” OR “OCT angiography” OR “optical coherence tomography angiography” AND “diabetes” OR “diabetes mellitus” OR “diabetic retinopathy” OR “diabetic maculopathy” OR “diabetic macular oedema” OR “diabetic macular ischaemia”. Of the 1456 studies initially identified, 107 studies were screened after duplication, and those articles that did not meet the selection criteria were removed. Finally, after looking for missing data, we included 135 studies in this review. Results: We present the common and distinctive findings in the analysed papers after the literature search including the diagnostic use of OCTA in diabetes mellitus (DM) patients. We describe previous findings in retinal vascularization, including microaneurysms, foveal avascular zone (FAZ) changes in both size and morphology, changes in vascular perfusion, the appearance of retinal microvascular abnormalities or new vessels, and diabetic macular oedema (DME) and the use of deep learning technology applied to this disease. Conclusion: OCTA findings enable the diagnosis and follow-up of DM patients, including those with no detectable lesions with other devices. The evaluation of retinal and choroidal plexuses using OCTA is a fundamental tool for the diagnosis and prognosis of DR.

Aqueous angiopoietin-like levels correlate with optical coherence tomography angiography metrics in diabetic macular edema.

To quantitatively detect aqueous levels of angiopoietin-like (ANGPTL)3, ANGPTL4, and ANGPTL6 and investigate their correlation with optical coherence tomography angiography (OCTA) findings in patients with diabetic macular edema (DME). This cross-sectional study included 23 patients (27 eyes) with type 2 diabetes and 16 control subjects (20 eyes). All patients underwent OCTA imaging and ultra-wide field fundus photography. Diabetic patients were categorized into two groups according to the presence or absence of diabetic retinopathy (DME group, 14 patients, 16 eyes); and non-diabetic retinopathy (NDR) group, 9 patients, 11 eyes, respectively. Aqueous levels of ANGPTL3, ANGPTL4, and ANGPTL6 were assessed using suspension array technology, and foveal-centered 3×3 mm2 OCTA scans were automatically graded to determine the central, inner, and full vessel density (CVD, IVD, FVD); central, inner, and full perfusion density (CPD, IPD, FPD), foveal avascular zone (FAZ) area, FAZ perimeter, and FAZ circularity index (FAZ-CI) on superficial capillary plexuses. Additionally, central subfield thickness (CST), cube volume (CV), and cube average thickness (CAT) were measured in a model of macular cube 512×128. Aqueous ANGPTL3 levels were not significantly different among the three groups (P>0.05). ANGPTL4 levels were significantly higher in the DME group than the control and NDR groups (P<0.0001 and P<0.001), while ANGPTL6 levels were significantly higher in the DME group than the control group (P<0.05). In the whole cohort, the aqueous ANGPTL3 levels correlated negatively with the IVD, FVD, IPD, and FPD, and positively with the CV and CAT. The aqueous ANGPTL4 levels correlated negatively with the CVD, IVD, FVD, CPD, IPD, and FPD, and positively with the FAZ perimeter, CST, CV, and CAT. The aqueous ANGPTL6 levels correlated negatively with the IVD, FVD, IPD, FPD, FAZ-CI and positively with CST, CV, CAT. ANGPTL4 and ANGPTL6 may be associated with vascular leakage in DME and may represent good targets for DME therapy. In addition, OCTA metrics may be useful for evaluating macular ischemia in DME.

In depth understanding of retinitis pigmentosa pathogenesis through optical coherence tomography angiography analysis: a narrative review.

Retinitis pigmentosa (RP) is the most recognized inherited retinal disorder involving progressive photoreceptors degeneration which eventually causes blindness. However, the pathogenesis of RP is still unclear, making it difficult to establish satisfying treatments. Evidence have been found to support the theory that vascular dysfunction is associated with the progression of RP. Optical coherence tomography angiography (OCTA) is a newly developed technology that enables visualization as well as quantitative assessment of retinal and choroidal vasculature non-invasively. Advances in OCTA have opened a window for in-depth understanding of RP pathogenesis. Here, we propose a hypothesis of RP pathogenesis based on the current OCTA findings in RP, which includes four stages and two important key factors, vascular dysfunction and microglia activation. Further, we discuss the future animal experiments needed and how advanced OCTA technology can help to further verity the hypothesis. The final goal is to explore potential treatment options with enhanced understanding of RP pathogenesis.

Decreased retinal microvasculature densities in pterygium.

To investigate the retinal vascular network alterations in eyes of patients with pterygium. Totally 18 left eyes from 18 female pterygium patients and 18 left eyes from 18 female healthy control subjects were enrolled. Optical coherence tomography angiography (OCTA) images were generated of the superficial retinal layer and deeper retinal layer of the macular retina for each eye. The microvascular (MIR) and macrovascular (MAR) densities were calculated and MIR, MAR, and total microvascular (TMI) density was compared in the healthy control and pterygium groups. In pterygium group, in the superficial retinal layer, the vascular density in superficial MIR, superior right (SR), inferior right (IR), right (R), superficial central annuli (SC)1, SC2, and SC3 decreased significantly in the macular area (P<0.05). Furthermore, the vascular density in all those decreased regions except R, was significantly and negatively correlated with the disease course (r=-0.6038 to -0.7762, P=0.0008), and the area size of pterygium (r=-0.6043 to -0.9508, P<0.05). For the deeper retinal layer, the density of deep total microvessel (DTMI), deeper MIR, SR, IR, R, DC2, and DC3 decreased significantly in macular area of pterygium patients (P<0.05). Furthermore, the vascular density in all those decreased regions was significantly and negatively correlated with the disease course (r=-0.6901 to -0.7795, P=0.0015), and the area size of pterygium (r=-0.6043 to -0.9563, P<0.05). No statistically significant differences and correlation was found in other region density (|r|<0.47, P>0.05). OCTA findings suggest that pterygium patients present with decreased retinal MIR density, and the major vascular alterations occurr mainly on the bitamporal side. The vascular density of the superficial SC1, SC2, SC3 adjacent to the foveal and deep layer of DC2, DC2 regions, significantly decreased.

Abstract 12881: Abnormal Retinal Perfusion Indices by Optical Coherence Tomography Angiography (OCTA) Associate With Abnormal Coronary Flow Reserve

Background: Retinal microvascular evaluation could serve as a marker for cardiovascular disease risk. OCTA is a noninvasive method to quantitatively assess the retinal microvasculature. Coronary flow reserve (CFR), an integrated measure of focal, diffuse, and small-vessel coronary artery disease, identifies patients at risk for cardiac death. We aimed to identify associations between OCTA findings and CFR in patients undergoing cardiac positron emission tomography (PET) testing. Methods: Subjects (n=60) underwent a stress myocardial perfusion PET scan to quantify CFR and OCTA of both eyes on same day. CFR is the ratio of myocardial blood flow at peak stress compared to rest and adjusted for baseline cardiac work. OCTA scans were analyzed using a custom-built software to quantify foveal avascular zone (FAZ) geometry and vessel density metrics in the retina, reflecting retinal microvasculature. We used Spearman to correlate markers of retinal microvasculature with CFR. Results: Demographics of enrolled subjects are shown in Table I. Baseline cardiac risk factors were common and 22 (37%) subjects had an abnormal stress test. Retinal perfusion as indicated by the vessel index (ρ=0.35, p=0.006) and vessel diameter index (ρ=0.27, p=0.039) in the superficial 6x6 mm slabs were positively correlated with CFR. There was a trend towards negative association between FAZ area in the retina slab and CFR (ρ= -0.17, p=0.1). Conclusions: CFR was correlated with retinal perfusion indices based on OCTA, suggesting a relationship between coronary and retinal vascular health. These data provide potential insight into systemic vascular health and could provide an additional tool to assess cardiac risk.

Review of OCT Angiography Findings in Diabetic Retinopathy: Insights and Perspectives

Diabetes mellitus (DM), a disorder rapidly growing in prevalence, is linked to the retinal microvasculature complication diabetic retinopathy (DR). As one of the leading global causes of vision impairment and loss, imaging techniques to detect and monitor DR must continue to improve in order to address this growing burden. Optical coherence tomography angiography (OCTA) is a nascent imaging modality that generates three-dimensional visualizations of the retinal and choroidal microvasculature. Compared to fluorescein angiography, the gold-standard imaging modality for retinal vessels, OCTA offers the advantages of being non-invasive, quick, and able to resolve the multiple plexuses within the retina. Quantitative OCTA studies have explored parameters such as vessel density (VD), foveal avascular zone (FAZ), acircularity index, vessel tortuosity (VT), and fractal dimension (FD) amongst DR patients. This review synthesizes the main trends emerging from quantitative OCTA-based studies of DR and interrogates them within the context of DR pathophysiology. We offer a glimpse into how analysis techniques have shifted in the years since OCTA came into existence, while speculating on its future role in clinical practice.

Effect of Foveal Pit Restoration in Foveal Avascular Zone after Surgery for Idiopathic Epiretinal Membrane.

PurposeTo investigate the relationship between ophthalmic parameters—including optical coherence tomography (OCT) and OCT angiography findings—and foveal pit restoration in eyes that had undergone vitrectomy for idiopathic epiretinal membrane (iERM) removal.MethodsThis study retrospectively analyzed data of patients who underwent pars planar vitrectomy for the removal of epirentinal membrane. Only eyes with iERM above stage 2 with a follow-up over 6 months were included. Baseline data and changes in ophthalmic parameters were analyzed from 3 months before to 12 months after surgery. Additionally, we stratified iERM patients into two groups (foveal pit restoration and no restoration group). Longitudinal comparison analyses between the two groups were done in best-corrected visual acuity (BCVA), central foveal thickness (CFT) and foveal avascular zone (FAZ) areas measurements using swept-source OCT and OCT angiography.ResultsForty-three patients with a mean age of 75 ± 5 years were enrolled. After surgery, BCVA, FAZ, and CFT showed improvements over time (all p < 0.002). Thirty-one patients were designated into the foveal pit restoration (R) group and 12 patients into the no restoration (NR) group. Differences in BCVA and FAZ area in both groups existed up to 6 months. However, BCVA improved and FAZ expanded (R, 0.20 ± 0.05 vs. NR, 0.18 ± 0.04) in both groups showing no statistical difference 12 months postsurgery. The CFT decreased in both groups, but the R group was thinner at every point compared to the NR group (all p < 0.05).ConclusionsThe removal of epirentinal membrane in pars planar vitrectomy significantly improves BCVA, decreases the CFT and expands the FAZ. Foveal pit restoration improves BCVA, CFT, and FAZ area possibly at a faster rate in the early months but long-term improvements could be achieved regardless of the status of foveal pit restoration.

Optic Nerve Head Optical Coherence Tomography Angiography Findings after Coronavirus Disease.

PurposeTo quantify the microvasculature density of the optic nerve head (ONH) using optical coherence tomography angiography (OCTA) analysis in patients recovered from Coronavirus Disease 2019 (COVID-19).MethodsIn a comparative cross-sectional, observational study, patients recovered from COVID-19 whose initial diagnosis was confirmed by a rRT-PCR of a nasopharyngeal sample were included in this study. OCTA of ONH was performed in included patients and normal controls. Vascular density (VD) of the all vessels (AV) and small vessels (SV) inside the disc and radial peripapillary capillary (RPC) network density were measured in COVID-19 recovered patients and compared with similar parameters in an age-matched group of normal controls.ResultsTwenty-five COVID-19 patients and twenty-two age-matched normal controls were enrolled in the study and one eye per participant was evaluated. The mean whole image SV VD in the COVID-19 group (49.31 1.93) was not statistically significantly different from that in the control group (49.94 . 2.22; P = 0.308). A decrease in RPC VD was found in all AV and SV VD measured, which became statistically significant in whole peripapillary SV VD, peripapillary inferior nasal SV VD, peripapillary inferior temporal SV VD, peripapillary superior nasal SV VD, and grid-based AV VD inferior sector (P 0.05). Inside disc SV VD in the COVID-19 group (49.43 4.96) was higher than in the control group (45.46 6.22) which was statistically significant (P = 0.021).ConclusionUnremarkable decrease was found in ONH microvasculature in patients who had recovered from COVID-19. These patients may be at risk of ONH vascular complications. Increase in inner disc SV VD may be an indicator of ONH hyperemia and edema.

OCT ANGIOGRAPHY IN DISEASES OF THE VITREORETINAL INTERFACE.

Present the use of Optical Coherence Tomography Angiography (OCTA) in vitreoretinal interface diseases and results of macular capillary network evaluation before and after idiopathic macular hole surgery (IMD). Prospective evaluation of functional results, anatomical and OCTA findings before and after IMD surgery. The group consists of 8 eyes of eight patients. Preoperatively and 1, 3 and 6 months after surgery, the best corrected visual acuity (BCVA) was examined, fundus photography was performed, examination of the macula by spectral-domain optical coherence tomography (SD OCT), determination of the stage of IMD according to Gases and also OCTA examination. The area of the foveal avascular zone (FAZ) and vascular density (VD) were evaluated by using of the OCTA. The operation was performed in all cases by transconjunctival suture 25G vitrectomy by one surgeon, always peeling the inner limiting membrane. An expansive gas, 7x 20% SF6, 1x 15% C3F8, was used for vitreous tamponade. In all 8 cases, the primary closure of the IMD occurred after the operation. The mean BCVA improved statistically significantly from 0.74 to 0.48 logMAR (p = 0.0023). The average FAZ area decreased from 0.345 mm² to 0.25 mm² after surgery (p = 0.0458). The mean VD increased from 7.93 mm-1 to 8.38 mm-1 (p = 0.2959). Assessment of the macular capillary network in patients with diseases of the vitreoretinal interface offers new findings and important details that can lead to prognostic information and a better understanding of the pathogenesis of the disease. We demonstrated a statistically significant reduction in FAZ in the eyes after successful IMD surgery and an indirect relationship between the improvement of BCVA and the change in FAZ area in our cohort.

Update on Optical Coherence Tomography and Optical Coherence Tomography Angiography Imaging in Proliferative Diabetic Retinopathy.

Proliferative diabetic retinopathy (PDR) is a major cause of blindness in diabetic individuals. Optical coherence tomography (OCT) and OCT-angiography (OCTA) are noninvasive imaging techniques useful for the diagnosis and assessment of PDR. We aim to review several recent developments using OCT and discuss their present and potential future applications in the clinical setting. An electronic database search was performed so as to include all studies assessing OCT and/or OCTA findings in PDR patients published from 1 January 2020 to 31 May 2021. Thirty studies were included, and the most recently published data essentially focused on the higher detection rate of neovascularization obtained with widefield-OCT and/or OCTA (WF-OCT/OCTA) and on the increasing quality of retinal imaging with quality levels non-inferior to widefield-fluorescein angiography (WF-FA). There were also significant developments in the study of retinal nonperfusion areas (NPAs) using these techniques and research on the impact of PDR treatment on NPAs and on vascular density. It is becoming increasingly clear that it is critical to use adequate imaging protocols focused on optimized segmentation and maximized imaged retinal area, with ongoing technological development through artificial intelligence and deep learning. These latest findings emphasize the growing applicability and role of noninvasive imaging in managing PDR with the added benefit of avoiding the repetition of invasive conventional FA.

Plane-wave ultrasound assessment of ocular blood flow in preeclampsia and correlation with optical coherence tomography angiography

We examined both eyes of 58 post-partum subjects within 72 hours of delivery with plane-wave ultrasound and optical coherence tomography angiography (OCTA). 8 had preeclampsia (PE), 21 severe PE (sPE). 9 chronic or gestational hypertension and 21 were controls. We performed plane-wave ultrasound with a Verasonics Vantage-128 and L22-14vXLF 18 MHz linear array, acquiring 3-angle compound images of the region of the optic nerve and choroid at 6 kHz for 3 s. Data were post-processed to obtain pulsatile flow characteristics of the central retinal artery and vein, the short posterior ciliary arteries and the choroid. Ultrasound revealed significantly elevated blood flow velocity and reduced resistance in sPE compared to controls. Spectral domain OCTA images were acquired with a Zeiss Plex Elite immediately before or after ultrasound. We analyzed 6x6 images centered on the macula and optic nerve to determine vascular density of the superficial and deep retina, and 3 i 3 images centered on the macula to determine foveal avascular zone area and vascular density of the choriocapillaris. Comparison of ultrasound with OCTA findings revealed significant correlations between flow velocity and resistance with vascular density in the superficial retina and choriocapillaris. These findings demonstrate a relationship between functional (ultrasound flow) and structural (OCTA vascular density) parameters in the eye, and especially in the choriocapillaris which we hypothesized would play role in the reduced flow resistance observed in sPE.

Correlation between optical coherence tomography angiography and multifocal electroretinogram findings in patients with diabetes mellitus

BackgroundDiabetic retinopathy is characterized by microvascular, neural and glial cell damage. Optical coherence tomography angiography (OCTA) can detect subclinical microvasculopathy while multifocal electroretinography (mfERG) can detect subclinical local retinal dysfunction before onset of clinically observable retinopathy. Here, we investigated the relationship between retinal dysfunction in multifocal electroretinography and vascular changes in optical coherence tomography angiography. MethodsThe study included 63 eyes of 63 diabetic patients without retinopathy (DM+DR-) and 68 eyes of 68 patients with non-proliferative diabetic retinopathy (NPDR). In addition, 64 eyes of 64 age and sex-matched subjects were included as the control group (CG). All subjects were evaluated using OCTA and mfERG. ResultsThe vascular density in the superficial and deep capillary plexus was significantly decreased in the DM+DR-group and the NPDR group compared with the CG group (except for the superficial foveal area, NPDR group vs. CG group) (p < 0.05). The vascular density of the superficial and deep parafoveal region was significantly decreased in the NPDR group compared to the DM+DR-group (p < 0.05). In circles of 2-, 5- and 10°, the amplitudes of the N1 and P1 waves were statistically significantly decreased in both the DM+DR- group and the NPDR group compared with the CG (p < 0.05). When the NPDR group was compared with the DM+DR- group, there was a statistically significant decrease in the amplitude of the N1 and P1 waves in the circles of 2- and 5° (p < 0.05). According to the correlation analysis, the amplitude and implicit times of the N1 and P1 waves showed weak-to-moderate correlation with vascular density (p < 0.05). ConclusionsThe decreased peaks of mfERG wave provides evidence regarding neurodegenerative effect of DM-associated hyperglycaemia. The decreased vascular density caused by hyperglycaemia was topographically associated with the retinal dysfunction and neurodegeneration.

OCT-Angiography Findings in Patients with Amblyopia: Comparison between Healthy Controls, Treatment-Responsive, and Treatment-Unresponsive Amblyopic Patients.

There is no consensus on whether amblyopia affects the retinal vascular plexus and morphology. Previous studies focused on the differences between amblyopic patients and normal controls without evaluating amblyopic eyes after patching. To evaluate differences in the superficial vascular density of amblyopic eyes, normal eyes, and amblyopic eyes reaching normal BCVA after patch therapy, OCTA was used. All patients underwent a comprehensive ophthalmological examination, including visual acuity, refraction, ocular motility tests, and anterior and posterior segment examination. OCTA was performed by an expert physician using the Zeiss Cirrus 5000-HD-OCT Angioplex (Carl Zeiss, Meditec, Inc., Dublin, OH, USA). OCTA scans were performed using a 3 × 3 mm2 and 6 × 6 mm2 fovea-centered image setting. The mean outer macular vessel density in the previously amblyopic group was 19.15 ± 0.51%. This was statistically significantly higher than in both the amblyopic group (18.70 ± 1.14%) and the normal controls (18.18 ± 1.40%) (p = 0.014). The previously amblyopic group also significantly differed from both normal controls and amblyopic eyes with regards to the inner (p = 0.011), outer (p = 0.006), and full (p = 0.003) macular perfusion. Finally, linear regression analysis revealed that BCVA was linearly correlated to outer perfusion in amblyopic (p = 0.003) and ex amblyopic eyes (p < 0.001). Considering the cross-sectional nature of our study, from our results, we can only hypothesize a possible correlation between light stimulation and retinal vasculature development. However, further longitudinal studies are needed to support this hypothesis.

Choroidal features in flat irregular pigment epithelial detachment associated with Chronic central serous chorioretinopathy: Avascular versus vascularized.

PurposeTo investigate the differences in the choroidal biomarkers between two forms of flat irregular pigment epithelial detachment (FIPED): avascular (aFIPED) and vascularized (vFIPED) in eyes with chronic central serous chorioretinopathy (CSC).Materials and methodsEnhanced depth imaging optical coherence tomography (EDI-OCT) was done in eyes with FIPED correlated to chronic CSC, fellow eyes, and also in healthy eyes from gender- and age-matched subjects. Eyes with FIPED were classified into two subgroups based on optical coherence tomography angiography (OCTA) findings: vFIPED and aFIPED. Different choroidal biomarkers such as subfoveal choroidal thickness (SFCT), total choroidal area (TCA), and choroidal vascular index (CVI) were compared between the groups.ResultsForty-four eyes from 42 patients with chronic CSC and FIPED along with 40 eyes from 20 healthy subjects were included. OCTA identified vascularization in 14 eyes in the FIPED group (31.8%). Mean SFCT was higher in the FIPED group compared to two other groups (p = 0.005). In comparison to patients with aFIPED, patients with vFIPED had lower SFCT (p = 0.003) and higher CVI (p = 0.020) based on multivariate analysis.ConclusionsIt seems that measurement of CVI along with SFCT may help to differentiate aFIPED from vFIPED in patients with CSC. Further longitudinal studies would be required to confirm the clinical significance of these findings.

Acute Posterior Ocular Toxoplasmosis: An Optical Coherence Tomography Angiography and Dye Angiography Study

ABSTRACT Purpose To compare Indocyanine Green (ICGA) and fundus fluorescein angiography (FFA) with Optical Coherence Tomography Angiography (OCTA) findings in toxoplasmic chorioretinitis (TCR). Methods Patients affected by active TCR were included. FFA, ICGA, and OCTA images were analyzed and lesions were compared between different modalities. Satellite dark dots (SDD) were compared between modalities. Results Fifteen patients were enrolled. The mean lesion area was similar between fundus photography (FP), FFA, and OCTA-Retina. The mean lesion area was similar between ICGA and OCTA-Choroid slab. ICGA and OCTA-Choroid showed a larger extension of the lesion compared to FP, FFA, and OCTA-Retina (p = .01, 0.0001, and 0.0002 for ICG angiography and p = .03, 0.008, and 0.0002 for OCTA-Choroid, respectively). On OCTA B-scans, the retinal flow defects were smaller than the underlying choroidal non-perfusion. The number of SDD was similar between ICGA and OCTA. Conclusions OCTA is a reliable method to assess retinal and choroidal involvement in TCR. OCTA confirmed a wider involvement of the choroid than the retina.

Optical Coherence Tomography Angiography Findings in Polycystic Ovary Syndrome.

To evaluate microstructure and vascularity of macula and optic disc in polycystic ovary syndrome (PCOS) by optical coherence tomography (OCT) and OCT angiography (OCTA). Descriptive study. Department of Ophthalmology and Department of Obstetrics and Gynecology, University of Health Sciences, Yüksek lhtisas Training and Research Hospital, Bursa, Turkey between January and June 2019. Fifty-nine patients with PCOS and 35 healthy controls were enrolled in the study. Foveal avascular zone (FAZ), the capillary density assessed in the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in the macula and was also measured in optic disc using the OCTA. The thicknesses of the retinal nerve fiber (RNFL), ganglion cell complex (GCC), and macula were measured by OCT. The capillary density in the macula and optic disc region were not a significant difference between the PCOS patients and healthy controls.The parafoveal superior, inferior, and temporal quadrant thickness was significantly higher in the study group compared to control group (p=0.047, p=0.033,and p=0.033, respectively). In patients with PCOS, there were negative correlations between IR and inferior RNFL, total and superior GCC thickness (r=-0.29 p= 0.027, r=-0.27 p=0.050, r=-0.31 p=0.029, respectively). Although no microvascular macular abnormalities were seen in PCOS patients, the parafoveal thickness significantly increased in all quadrants, except the nasal quadrant. In patients with PCOS, IR, dyslipidemia may affect the structural integrity of the retina. Further longitudinal follow-up studies are needed to determine whether PCOS has any effect on OCTA findings. Key Words: Polycystic ovary syndrome, Retina, Optical coherence tomography, Optical coherence tomography angiography.

Optical Coherence Tomography and Optical Coherence Tomography Angiography Findings in Amblyopic Patients

Abstract Background: Amblyopia is a unilateral or bilateral decrease of visual acuity caused by deprivation of pattern vision or abnormal binocular interaction, for which no cause can be detected by physical examination of the eye and which in some cases, can be reversed by therapeutic measures. Aim of Study: To examine amblyopic eyes in a comparative study with age matched controls to detect possible changes in macular, Ganglion cell layer (GCL), choroid, peripapillary retinal nerve fiber layer (RNFL) measurements using optical coherence tomography (OCT), and foveal avascular zone (FAZ) area using optical coherence tomography angiography (OCTA). Patients and Methods: A case control observational study. Forty eyes of forty participants divided into 4 groups. 30 patients with unilateral amblyopia due to strabismus, ani-sometropia and sensory deprivation (each group included 10 patients) compared with 10 controls. OCT & OCTA were done using (Heidelberg Engineering, OCT spectralis, Germany). Results: As regard mean GCL thickness and FAZ area in superficial capillary plexus (SCP) and deep capillary plexus (DCP), there was no statistically significant difference between patients' groups and control group. Also there was no statisti-cally significant difference in RNFL thickness between am-blyopic groups and control group except nasal quadrant in strabismic and sensory deprivative groups, there was statisti-cally significant difference. For sub-foveal thickness there was statistically significant difference in strabismic, anisome-tropic groups, but no significant difference in sensory depriv-ative group. Conclusion: Patients with unilateral amblyopia were prone to have a higher central macular thickness in sensory depriv-ative group only, with no difference in thickness regarding other groups, and thinner nasal quadrant RNFL thickness in strabismic and sensory deprivative groups only, when compared to control eyes.

Examination of Age-Related Retinal Vascular Changes in the Macula Using Optical Coherence Tomography Angiography of the Eyes After Cataract Surgery.

PurposeOptical coherence tomography angiography (OCTA) allows noninvasive observation of the retinal vasculature, and image analysis can be used to calculate the retinal vessel density and foveal avascular zone (FAZ) area. A previous study showed that macular vessel density and the signal strength index (SSI) of OCTA images increased significantly after cataract surgery. However, the effect of aging on OCTA analysis remains unclear. This study aimed to investigate age-related changes in macular vascularization while excluding the effects of cataracts.Patients and MethodsOCTA imaging of the macula was performed in adult patients who had undergone cataract surgery between February 2018 and May 2019 and in young healthy participants between April 2017 and April 2018.ResultsThe median (quartiles) age of the overall study population was 59.0 (27.0, 69.0) years, and no severe refractive error was observed (axial length: 24.2 ± 1.3 [mean ± SD] mm; spherical equivalent: 0.75 [−2.25, 0.00] diopter). When we investigated the relationship between macular vessel density and age after excluding the effects of cataracts, we found that the macular vessel density showed age-related changes even in the absence of the effects of the SSI. However, the FAZ area was not affected by age.ConclusionMacular vessel density decreased with age, even when the effects of cataracts were excluded. The effects of age and cataracts should be considered when designing studies and interpreting OCTA findings of the retinal vasculature.

Optical Coherence Tomography and Optical Coherence Tomography Angiography Findings in Multiple Sclerosis Patients

ABSTRACT In addition to ocular neurodegeneration in multiple sclerosis (MS), accompanying microvascular changes in the retina are thought to occur. In this study we sought to compare retinal neurodegenerative changes using optical coherence tomography (OCT) and microvascular changes using OCT angiography (OCTA) of MS patients and healthy controls. This cross-sectional study included 164 eyes of 83 MS patients and 114 eyes of 57 healthy control subjects. There were significant differences in retinal nerve fibre layer (RNFL), ganglion cell complex (GCC), and radial peripapillary capillary (RPC) vessel density (VD) between the MS group and the control group, but no significant differences in superficial capillary plexus (SCP) VD and deep capillary plexus (DCP) VD, foveal avascular zone (FAZ), non-flow area (NFA), and choriocapillary flow (CCF) values. Comparing the eyes with and without previous optic neuritis showed no significant differences in the OCT and OCTA measurements. A negative correlation was found between the expanded disability status scale score and disease duration and the RNFL and GCC values. A positive correlation was found between the RNFL and GCC values and the SCP VD and RPC VD. In MS patients, RPC VD values decreased in correlation with decreases in RNFL and GCC. This reduction increased as the disease duration and disability criteria increased. OCT and OCTA may be important biomarkers in MS.

UNCOMPLICATED PACHYCHOROID IN RELATION TO OBSESSIVE-COMPULSIVE DISORDER: AN OCT-ANGIOGRAPHY STUDY

BackgroundThe aim of this study was to evaluate potential changes in choroidal flow in patients with newly diagnosed obsessive-compulsive disorder based on optical coherence tomography angiography findings and to investigate the relationship between subfoveal choroidal thickness and choriocapillaris flow area. MethodsThis prospective study included newly diagnosed obsessive-compulsive disorder patients and healthy controls. All patients underwent enhanced depth imaging-optical coherence tomography imaging to assess the subfoveal choroidal thickness and optical coherence tomography angiography imaging to evaluate the choriocapillaris flow area. ResultsA total of 55 patients with obsessive-compulsive disorder and 50 controls were included. The mean subfoveal choroidal thickness was significantly greater in the obsessive-compulsive disorder group compared to the control group (p˂0.001). Regarding the choriocapillaris flow area, the values for area with a radius of 1 mm, 2 mm and 3 mm were significantly lower in the obsessive-compulsive disorder group than in the control group (p=0.019, p=0.014, and p=0.004, respectively). There was a significant negative correlation between subfoveal choroidal thickness and choriocapillaris flow area with a radius of 1mm (r=-0.387, p=0.024). ConclusionChoroidal changes in obsessive-compulsive disorder patients suggest the choroidal features of uncomplicated pachychoroid. Obsessive-compulsive disorder may be prone to a spectrum of conditions characterized by pachychoroid features.