Swept source optical coherence tomography angiography in patients treated with hydroxychloroquine: correlation with morphological and functional tests

Optical coherence tomography and optical coherence tomography angiography findings in optic nerve hypoplasia and their relationships with visual acuity

This study aimed to quantitatively assess the thickness of the peripapillary retinal nerve fiber layer (pRNFL) thickness, as well as the microvascular alterations in the macula and peripapillary regions, in optic nerve hypoplasia (ONH) patients compared to normal controls. This was achieved through the utilization of spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA), with a specific focus on elucidating the association between these structural alterations and visual acuity. We included a total of 17 eyes of 12 ONH patients, and 34 eyes of age-matched 34 healthy controls. The pRNFL thickness was quantified using SD-OCT, while OCTA facilitated the visualization and measurement of the microvascular structure images of the superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and radial peripapillary capillary (RPC) segment in the macula and peripapillary area. pRNFL thickness was measured for eight sectors (superior, temporal, inferior, nasal, superotemporal, superonasal, inferotemporal, and inferonasal). SRCP, DRCP, and RPC were measured for four sectors (superior, temporal, inferior, and nasal). Age, gender, and spherical equivalent refractive errors were statistically adjusted for the analysis. Associations of structural parameters with visual acuity in ONH patients were analyzed using Spearman correlation analysis. pRNFL thickness was significantly thinner in ONH patients than in controls for all sectors. Vessel densities of temporal and nasal sectors in DRCP were significantly higher in ONH patients, but vessel densities of the inferior sector in RPC were significantly lower than those in controls. For all sectors, pRNFL thickness was strongly associated with visual acuity in ONH patients. ONH patients showed significant pRNFL thinning and microvascular alterations compared to controls, and pRNFL thickness was strongly associated with visual function. OCT and OCTA are useful tools for evaluating optic disc hypoplasia and its functional status.

MICROVASCULATURE ALTERATIONS OF PERIPAPILLARY RETINA AND MACULA IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITHOUT OCULAR INVOLVEMENT BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PURPOSE

To evaluate microvasculature alterations of the peripapillary retina and macula and to assess whether the changes can detect preclinical retinopathy in systemic lupus erythematosus patients.

METHODS

Cross-sectional study of 32 systemic lupus erythematosus patients without retinopathy and 22 normal controls. Optical coherence tomography angiography was used to measure the microvasculature of the peripapillary retina and macula. Vessel densities (VD, %) and fractal dimensions of superficial capillary plexus (SCP) and deep capillary plexus were calculated.

RESULTS

Compared with controls, macular vessel densities of the whole image SCP (macular vessel density of SCP-wi) and macular vessel density of inferior SCP (macular vessel density of SCP-i) were significantly reduced in systemic lupus erythematosus patients ( P < 0.05). The peripapillary vessel densities (peripapillary vessel density [pVD]) of a 2.5-mm circle of SCP (pVD of SCP Φ2.5 ), pVD of SCP Φ3.5 , and pVD of inferior region of the inner circle of SCP (pVD of SCP-ii) were significantly reduced in patients treated with hydroxychloroquine >5 years. Macular vessel density of SCP-wi declined with age (β = -0.12; P < 0.01) and pVD of SCP-ii declined with hydroxychloroquine cumulative dose (β = -0.01; P < 0.01). Macular vessel density of SCP-i had the best discrimination power of 0.77 ( P < 0.01).

CONCLUSION

Systemic lupus erythematosus patients without ocular involvement had microvasculature alterations that were particularly evident in the SCP. Peripapillary retina microvasculature may be reduced in patients with longer hydroxychloroquine treatment.

Effects of hydroxychloroquine therapy on choroidal volume and choroidal vascularity index

PURPOSE

To determine changes in choroidal volume (CV) and choroidal vascularity index (CVI) in patients on hydroxychloroquine (HCQ) therapy.

METHODS

Retrospective analysis of patients on HCQ therapy. CV and CVI were assessed below the central foveal region on spectral-domain optical coherence tomography using an automatic denoising and localization algorithm. CV and CVI were compared with age-matched controls. Regression analyses were performed to generate associations between CV and CVI with demographics and HCQ treatment parameters. Associations were assessed using a generalized estimating equation model adjusted for intra-subject inter-eye correlations.

RESULTS

A total of 137 adult patients (23 males and 114 females) were included. Mean age was 45.6 ± 13.7 years and most patients identified as Caucasian (79%). Total duration of HCQ therapy ranged from 3 months to 20 years. Daily HCQ intake varied from 150-600 mg (mean = 304 mg), while cumulative doses ranged from 18-2,800 g. At presentation, the median CV was 0.51 (IQR:0.356-0.747) mm, and median CVI was 0.559 (IQR:0.528-0.578). Increased cumulative HCQ dose was associated with decreased CV (p = 0.006). Compared to age-matched controls, CV, CVI, and luminal area were significantly lower in the study group (p = 0.0003, 0.0001, and 0.0002).

CONCLUSION

In this study, we present a novel analysis of key biomarkers which predate the occurrence of HCQ retinopathy. Choroidal volume and vascularity index are significantly reduced in patients on HCQ therapy, especially at higher cumulative doses. These findings suggest new tools to guide medical decision-making for patients receiving HCQ therapy for rheumatologic diseases.

Quantitative assessment of retinal vasculature changes in systemic lupus erythematosus using wide-field OCTA and the correlation with disease activity

Purpose

To assess the retinal vasculature changes quantitatively using wide-field optical coherence tomography angiography (OCTA) in systemic lupus erythematosus (SLE), and explore its correlation with systemic clinical features.

Design

Prospective, cross-sectional, observational study.

Participants and controls

Patients with SLE who presented to the Ophthalmology Department of Peking Union Medical College Hospital from November 2022 to April 2023 were collected. The subjects were divided into retinopathy and without retinopathy groups. Age and gender-matched healthy subjects were selected as controls.

Methods

Patients with SLE and control subjects were imaged with 24×20 mm OCTA scans centered on the fovea and 6×6 mm OCTA scans centered on the optic disc. The sub-layers of OCTA images were stratified by the built-in software of the device and then the retinal thickness and vessel density were measured automatically. The characteristics of retinal OCTA parameters of SLE and its correlation with systemic clinical indicators of patients without retinopathy were analyzed.

Main outcome measures

OCTA parameters, visual acuity, intraocular pressure, and systemic clinical indicators of patients such as disease activity index, autoimmune antibodies, and inflammatory marker levels were collected.

Results

A total of 102 SLE patients were included, 24 of which had retinopathy, and 78 had unaffected retina. Wide-field OCTA could effectively detect retinal vascular obstruction, non-perfusion area, and morphological abnormalities in patients with lupus retinopathy. SLE patients without retinopathy had significantly higher retinal superficial vessel density (SVD) in foveal (P=0.02), para-foveal temporal (P=0.01), nasal (P=0.01), peripheral foveal temporal (P=0.02), and inferior areas (P=0.02), as well as subregion temporal (P=0.01) and inferior areas (P=0.03) when compared with healthy controls (n=65 eyes from 65 participants). The area under curve (AUC) value of subregion inferior SVD combined parafoveal temporal SVD was up to 0.70. There was a significantly positive correlation between SVD and disease activity in SLE without retinopathy group. Patients with severe activity had the most significant increase in SVD.

Conclusion

Wide-field OCTA can provide a relatively comprehensive assessment of the retinal vasculature in SLE. In the absence of pathological changes of the retina, the SVD was significantly increased and was positively correlated with the disease activity of SLE.

Evaluation of early retinal changes in patients on long-term hydroxychloroquine using optical coherence tomography angiography

Background

Connective tissue diseases (CTD), including systemic lupus erythematosus and rheumatoid arthritis (RA), have long been treated with hydroxychloroquine (HCQ). However, prolonged HCQ use poses a risk of adverse effects, particularly retinopathy.

Objective

To detect early retinal changes assessed by optical coherence tomography angiography (OCTA) in CTD patients with long-term HCQ treatment and to explore the relationship between OCTA parameters and the concentrations of HCQ and its metabolites.

Design

A cross-sectional study conducted from March 2020 to October 2021 at the First Affiliated Hospital of Anhui Medical University.

Methods

The area and perimeter of the foveal avascular zone (FAZ), the thickness of the fovea and parafovea, and the vascular density of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in each area of the macula were measured by OCTA in 43 CTD patients treated with HCQ for over 6 months. Meantime, blood concentrations of HCQ and its metabolites were determined by high-performance liquid chromatography-tandem mass spectrometry, and the clinical documents of all 43 involved patients were collected.

Results

There is no significant correlation between OCTA outcomes and the patient's age, disease duration, and weight-dependent dose. HCQ cumulative duration positively correlated with FAZ area and perimeter (r = 0.419, p = 0.005 and r = 0.407, p = 0.007, respectively) and negatively correlated with the foveal vessel density in DCP (r = -0.378, p = 0.012). HCQ cumulative dose had a positive correlation with FAZ area and perimeter (r = 0.445, p = 0.003 and r = 0.434, p = 0.004, respectively) and had a negative correlation with foveal vessel density in SCP and DCP (r = -0.383, p = 0.011 and r = -0.424, p = 0.005, respectively). OCTA outcomes did not correlate with HCQ and its metabolite concentrations.

Conclusion

OCTA could be used to detect microvascular changes in the macula of CTD patients with long-term HCQ therapy. It was not found the concentrations of HCQ and its metabolites were associated with retinal vascular changes.

Astigmatism Influences Quantitative and Qualitative Analysis in Optical Coherence Tomography Angiography Imaging

Purpose

The purpose of this paper was to study the influence of astigmatism in optical coherence tomography angiography (OCTA) images in a quantitative and qualitative analysis.

Methods

This was a prospective, cross-sectional study. We included 110 eyes of 110 patients: 20 eyes without astigmatism and 90 eyes with astigmatism ≥0.5 diopters (D). We performed a macula centered OCTA as a reference image. In patients without astigmatism, registered follow-up scans were performed after induction of -1 and -2 D astigmatism. In patients with astigmatism, we performed the follow-up scan after astigmatism correction. We used a set of cylindrical lenses attached to the camera head of the SPECTRALIS (Heidelberg Engineering, Heidelberg, Germany). A quantitative and qualitative analysis of the superficial vascular complex (SVC) and deep vascular complex (DVC) was performed. The main outcome measures were vessel density (VD), image quality, and the presence of artifacts.

Results

Mean VD of the SVC was significantly higher in the reference images compared with the images after induction of -2 D. Differences with -1 D were nonsignificant. Higher degrees of astigmatisms had higher VD dropout (0.012-0.02 per diopter in SVC). Astigmatism axis showed no relevance in our cohort. Image quality assessed by two independent observers was graded as higher in images without astigmatism. Defocus and attenuation were more prevalent in images with astigmatism.

Conclusions

Astigmatism of -2 D affects quantification of VD in OCTA images, mainly affecting the SVC, as well as the subjective quality assessment. Correction of this refractive error might be necessary for an accurate quantitative assessment of OCTA images.

Translational Relevance

Correcting astigmatism of 2 D or greater appears to be necessary when analyzing OCTA images.

Subclinical macular vessel density alterations in patients with juvenile systemic lupus erythematosus

OBJECTIVE

The aim is to evaluate subclinical alterations of macular microvasculature in patients with juvenile systemic lupus erythematosus (JSLE).

METHODS

This is a cross-sectional study of 29 eyes of 29 patients diagnosed with JSLE and 29 eyes of 29 healthy controls. The vessel density (VD) of the superficial capillary plexus (SCP), intermediate capillary plexus (ICP), deep capillary plexus (DCP), choriocapillaris (CC), and area of foveal avascular zone (FAZ) was measured using optical coherence tomography angiography (OCTA). A multiple linear regression analysis was performed to evaluate the effects of disease duration and activity on OCTA parameters.

RESULTS

The VD of total (p = .007) and the superior (p = .014) and inferior (p = .004) quadrants in SCP was significantly lower in children with JSLE. The VD of total and all quadrants in ICP decreased (p = .015, p = .0045, p = .015, p = .033), except that of the temporal quadrant (p = .366). The total (p = .011) and superior quadrant (p<.01) DCP-VD showed a significant decrease in children with JSLE. The decrease in VD in the total (p = .003) and nasal quadrant (p = .017) of CC was also remarkable. No significant difference in the FAZ area was found between the two groups (p = .774). Multiple linear regression analyses adjusted for age, spherical equivalent, and intraocular pressure were conducted. No contributing factor to OCTA parameters was found.

CONCLUSIONS

We demonstrated decreased VD in all layers of the retina and CC in patients with JSLE without ocular involvement. Early screening and close follow-up were recommended.

The association between cardiovascular risk profile and ocular microvascular changes in patients with non-ST elevation myocardial infarction

PURPOSE

We aimed to evaluate the association between ocular microvasculature (vascular density) on optical coherence tomography-angiography (OCT-A) and the cardiovascular risk profile of patients hospitalized for non-ST-elevation myocardial infarction (NSTEMI) patients.

METHODS

Patients admitted to the intensive care unit with the diagnosis of NSTEMI and undergoing coronary angiography were divided into 3 groups as low, intermediate, and high risk according to the SYNTAX score. OCT-A imaging was performed in all three groups. Right-left selective coronary angiography images of all patients were analyzed. The SYNTAX and TIMI risk scores of all patients were calculated.

RESULTS

This study included opthalmological examination of 114 NSTEMI patients. NSTEMI patients with high SYNTAX risk scores had significantly lower deep parafoveal vessel density (DPD) than patients with low-intermediate SYNTAX risk scores (p < 0.001). ROC curve analysis found that a DPD threshold below 51.65 % was moderately associated with high SYNTAX risk scores in patients with NSTEMI. In addition, NSTEMI patients with high TIMI risk scores had significantly lower DPD than patients with low-intermediate TIMI risk scores (p < 0.001).

CONCLUSIONS

OCT-A may be a non-invasive useful tool to assess the cardiovascular risk profile of NSTEMI patients with a high SYNTAX and TIMI score.

Retinal alterations in evaluation of rheumatoid arthritis with chloroquine treatment: A new approach

OBJECTIVE

To evaluate the effect of hydroxychloroquine on conjunctival and retinal microvascular density in rheumatoid arthritis (RA) patients.

METHODS

Ten healthy controls, 10 RA patients who had not been treated with hydroxychloroquine, and 10 RA patients who had been treated with chloroquine for more than 5 years were recruited. Optical coherence tomography (OCTA) was used to examine the conjunctival and superficial and deep retinal microvascular density and compared the differences in microvascular density between the three groups.

RESULTS

The vascular density in RA group in superficial microvascular was significantly lower than that in control group (p < 0.001). Compared with RA group, the chloroquine group showed statistically significantly lower microvascular (p < 0.001) and deep microvascular (p = 0.018). Superficial microvascular was positively correlated with conjunctival vessel density in RA patients (r = 0.868, p = 0.0048).

CONCLUSIONS

The use of chloroquine could further reduce the vascular density in the absence of statistical difference in the course of the disease.

Application of optical coherence tomography angiography for microvascular changes in patients treated with hydroxychloroquine: a systematic review and meta-analysis

BACKGROUND

Retinal toxicity with long-term hydroxychloroquine (HCQ) treatment is a major concern. This systematic review aims to assess the application of optical coherence tomography angiography (OCTA) to detect microvascular alterations in patients under HCQ.

METHODS

PubMed, Scopus, Web of Science, and Cochrane Library databases were systematically searched until January 14, 2023. Studies using OCTA as a primary diagnostic method to evaluate the macular microvasculature of HCQ users were included. Primary outcomes were macular vessel density (VD) and foveal avascular zone (FAZ) at the superficial (SCP) and deep (DCP) capillary plexus. Meta-analysis was performed using a random-effects model.

RESULTS

Of 211 screened abstracts, 13 were found eligible, enrolling 989 eyes from 778 patients. High-risk patients due to longer duration of treatment presented lower VD in the retinal microvasculature than those with low-risk in SCP (P = 0.02 in fovea; P = 0.004 in parafovea) and in DCP (P = 0.007 in fovea; P = 0.01 in parafovea). When compared with healthy controls, HCQ users had lower VD in both plexus-no quantitative synthesis was presented.

CONCLUSIONS

Microvascular changes were found in autoimmune patients under HCQ treatment without any documented retinopathy. However, the evidence produced so far does not allow to draw conclusion concerning the effect of drug as studies were not controlled for disease duration.

Preclinical ocular changes in systemic lupus erythematosus patients by optical coherence tomography

OBJECTIVE

The aim of the present study was to detect preclinical changes in SLE patients in retinal microvascularization or retinal and optical nerve structure by optical coherence tomography.

METHODS

This cross-sectional, single-centre study aimed to describe structural changes [macular and retinal nerve fibre layer (RNFL) thickness] by structural spectral-domain optical coherence tomography (SD-OCT) and perifoveal vascular [vessel density (VD) and vascular perfusion (VP) and foveal avascular zone (FAZ) structural parameters] findings by OCT angiography (OCTA) in 78 SLE patients and 80 healthy volunteers. In addition, we analysed their association with clinical and laboratory parameters, medications received, disease duration, and SLE activity and damage.

RESULTS

Structural parameters by SD-OCT and perifoveal vascular parameters by OCTA were decreased in SLE patients compared with controls. OCTA parameters (VD, VP and FAZ circularity) and macular thickness were also decreased in patients with longer disease duration (>10 years). The presence of aPLs was associated with a decreased RNFL thickness, mainly in the inferior quadrants. Patients developing APS also showed decreased RNFL thickness and OCTA flow changes. SD-OCT and OCTA results were not associated with disease activity. Foveal structural parameters were lower in patients with higher damage score.

CONCLUSION

SD-OCT and OCTA can detect preclinical structural and microcirculatory changes in SLE patients. Structural and perifoveal vascular macular changes in SLE patients are related to disease duration. Macular structural parameters were impaired in patients with higher disease damage. APS seems to be associated with preclinical damage to the optic nerve and impairment of the perifoveal microvasculature.

Subclinical retinopathy in systemic lupus erythematosus patients - optical coherence tomography study

Introduction

The aim was to detect subclinical structural retinal abnormalities in optical coherence tomography (OCT) in ophthalmologically asymptomatic systemic lupus erythematosus (SLE) patients without signs of lupus retinopathy or drug toxicity in fundus examination and in OCT and to assess the relationship between OCT parameters and disease activity, therapy type and burden on other organs to demonstrate the utility of OCT in early retinal impairment in SLE patients.

Material and methods

Cross-sectional study. Thirty-three SLE patients (57 eyes) and 31 healthy individuals (56 eyes) were enrolled in the study. We excluded patients with evidence of lupus retinopathy or hydroxychloroquine (HCQ) toxicity on OCT or fundus examination to reveal any subclinical changes. All patients underwent full ophthalmologic examination in the slit lamp including best corrected visual acuity, tonometry, and OCT. The Kolmogorov-Smirnov distribution test was used to assess the normal distribution in quantitative values. The differences between the individual measured parameters in the groups were analyzed using the Mann-Whitney U test. Spearman's rank correlation test was used to assess the correlation between the measured parameters and quantitative clinical data.

Results

There was no difference in the OCT findings between SLE and healthy control groups. Among the study group a negative correlation was found between disease duration and age and retinal nerve fiber layer thickness in the inferior quadrant (p = 0.0063, p = 0.0036). No correlations were observed between examined retinal parameters and duration of hydroxychloroquine therapy, hydroxychloroquine as well as chloroquine cumulative dose and disease activity indices.

Conclusions

Optical coherence tomography is a widespread ophthalmic modality used for SLE retinopathy and HCQ toxicity screening. Our study did not demonstrate its clinical potency in diagnosis of subclinical retinal involvement. An optical coherence tomography device seems to be less sensitive in subclinical retinal impairment detection than optical coherence tomography angiography.

Review of Retinal Imaging Modalities for Hydroxychloroquine Retinopathy

This review provides an overview of conventional and novel retinal imaging modalities for hydroxychloroquine (HCQ) retinopathy. HCQ retinopathy is a form of toxic retinopathy resulting from HCQ use for a variety of autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus. Each imaging modality detects a different aspect of HCQ retinopathy and shows a unique complement of structural changes. Conventionally, spectral-domain optical coherence tomography (SD-OCT), which shows loss or attenuation of the outer retina and/or retinal pigment epithelium-Bruch's membrane complex, and fundus autofluorescence (FAF), which shows parafoveal or pericentral abnormalities, are used to assess HCQ retinopathy. Additionally, several variations of OCT (retinal and choroidal thickness measurements, choroidal vascularity index, widefield OCT, en face imaging, minimum intensity analysis, and artificial intelligence techniques) and FAF techniques (quantitative FAF, near-infrared FAF, fluorescence lifetime imaging ophthalmoscopy, and widefield FAF) have been applied to assess HCQ retinopathy. Other novel retinal imaging techniques that are being studied for early detection of HCQ retinopathy include OCT angiography, multicolour imaging, adaptive optics, and retromode imaging, although further testing is required for validation.

Analysis of choroidal thickness in juvenile systemic lupus erythematosus and its correlation with laboratory tests

BACKGROUND

The aim of this study is to investigate the alterations of choroidal thickness (CT) in juvenile systemic lupus erythematosus (JSLE) using enhanced depth imaging optical coherence tomography (EDI-OCT). We also aimed to assess whether CT parameters correlated with systemic health status in JSLE patients.

METHODS

JSLE patients and age- and sex-matched healthy subjects were recruited. A detailed ophthalmological examination was applied to all participants. CT measurements were acquired in the macular region using EDI-OCT. Moreover, a spectrum of laboratory tests was examined to evaluate the systemic conditions, and the Th1/Th2/Th17/Treg cytokine profiles in the peripheral blood were also analyzed in JSLE group.

RESULTS

A total of 45 JSLE patients with no visual impairment and 50 healthy individuals were enrolled in the study. CT values in the macular region were decreased in JSLE patients when compared with healthy controls, even adjusting for age, axial length and refraction. There were no significant correlations between CT and cumulative dose of hydroxychloroquine or duration of hydroxychloroquine use (all P > 0.05). The average macular, temporal and subfoveal CT in JSLE group was negatively correlated with IL-6 and IL-10 (all P < 0.05), but had no significant correlations with other laboratory results (all P > 0.05).

CONCLUSIONS

JSLE patients without ocular involvement may have significant variations in choroidal thickness at the macular area. Choroidal alterations might be associated with the systemic cytokine profiles in JSLE.

The Impact of Systemic Medications on Retinal Function

This study will provide a thorough review of systemic (and select intravitreal) medications, along with illicit drugs that are capable of causing various patterns of retinal toxicity. The diagnosis is established by taking a thorough medication and drug history, and then by pattern recognition of the clinical retinal changes and multimodal imaging features. Examples of all of these types of toxicity will be thoroughly reviewed, including agents that cause retinal pigment epithelial disruption (hydroxychloroquine, thioridazine, pentosan polysulfate sodium, dideoxyinosine), retinal vascular occlusion (quinine, oral contraceptives), cystoid macular edema/retinal edema (nicotinic acid, sulfa-containing medications, taxels, glitazones), crystalline deposition (tamoxifen, canthaxanthin, methoxyflurane), uveitis, miscellaneous, and subjective visual symptoms (digoxin, sildenafil). The impact of newer chemotherapeutics and immunotherapeutics (tyrosine kinase inhibitor, mitogen-activated protein kinase kinase, checkpoint, anaplastic lymphoma kinase, extracellular signal-regulated kinase inhibitors, and others), will also be thoroughly reviewed. The mechanism of action will be explored in detail when known. When applicable, preventive measures will be discussed, and treatment will be reviewed. Illicit drugs (cannabinoids, cocaine, heroin, methamphetamine, alkyl nitrite), will also be reviewed in terms of the potential impact on retinal function.

CHOROIDAL VASCULARITY INDEX IN HYDROXYCHLOROQUINE TOXIC RETINOPATHY: A Quantitative Comparative Analysis Using Enhanced Depth Imaging In Spectral Domain Optical Coherence Tomography

PURPOSE

To investigate choroidal involvement in eyes of patients treated with hydroxychloroquine (HCQ), by quantifying the choroidal vascularity index (CVI) and other choroidal biomarkers.

METHODS

Vertical enhanced depth imaging spectral domain optical coherence tomography (SD-OCT) scans were performed in eyes with either advanced-stage or mild HCQ toxic retinopathy, as well as in healthy age-matched and sex-matched controls. Based on SD-OCT scans, the subfoveal and mean choroidal thickness (ChT) was measured. The CVI, total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were calculated based on a binarization image process. These variables were computed and compared between the three groups (i.e., advanced stage, mild toxicity, and healthy controls).

RESULTS

Forty-eight eyes of 47 patients under HCQ (26 eyes presented with advanced stage HCQ toxicity and 22 eyes with mild toxicity) and 34 eyes of 31 healthy controls were included. Both CVI and ChT were significantly different between the three groups ( P < 0.001, P < 0.001). When comparing the advanced stage toxicity group to healthy controls, both the subfoveal and the mean ChT were diminished ( P < 0.001). The CVI, TCA, LCA, and SCA were significantly lower in the advanced stage of toxicity group when compared with controls ( P < 0.001, <0.00001, <0.0001, and P = 0.0094, respectively).

CONCLUSION

Our study suggests that eyes with HCQ toxic retinopathy, especially at advanced stages, present with choroidal impairment, giving further pathophysiological insights into the unfolding of this retinal toxicity.

Optical coherence tomography angiography quantitative analysis of retinal and choroidal microvasculature in patients with dyslipidemia

INTRODUCTION

The purpose of this investigation was to report swept source-optical coherence tomography angiography (SS-OCTA) quantitative information of retinal and choroidal microvascularization in patients with dyslipidemia (DL).

METHODS

We performed a retrospective study. The study enrolled 37 eyes of 20 patients with DL and 40 eyes of 23 healthy subjects. OCTA quantitative parameters (vessel density (VD) and foveal avascular zone (FAZ) area of superficial capillary plexus (SCP), middle capillary plexus (MCP), deep capillary plexus (DCP) and choriocapillaris (CC)) in 6 mm × 6 mm and 4,5 mm × 4,5 mm cubes were recorded.

RESULTS

No differences in VD in SCP, MCP and DCP were demonstrated between DL group and control group (p > 0,05). Conversely, VD in the central region at CC was diminished in patients with DL in both cubes (p < 0,05). Moreover, total VD in CC was decreased in the DL group in 6 mm × 6 mm cube (p < 0,05). Regarding FAZ area, we demonstrated and enlargement of FAZ in each retinal capillary plexus, but it did not reach statistical significance (p > 0,05).

CONCLUSION

We objectified a diminution of VD in the CC, suggesting that DL mainly affects the choroidal microvasculature. Nonetheless, further studies with a larger population are needed.

Evaluation of Subclinical Retinal Disease in Patients Affected by Systemic Lupus Erythematosus with No Evidence of Ocular Involvement-An Optical Coherence Tomography Angiography Original Study

Lupus retinopathy is the second most common eye involvement in systemic lupus erythematosus (SLE), associated with significant visual deterioration and well-known negative prognostic factor for survival. Ocular manifestation in SLE, relating the retina, ranges from asymptomatic vascular involvement to vision devastating vascular occlusions. Subclinical microvascular changes are undetectable in slit lamp examination, hence are underdiagnosed. Optical coherence tomography angiography (OCTA) is a novel, easy to interpret and non-invasive technique that allows retinal vessels visualization. OCTA simplifies clinical approach and measures the severity of decreased perfusion. The aim of the study was to demonstrate the retinal vascularization in a subclinical stage of ocular involvement in a cohort of SLE patients. Thirty-three patients (57 eyes) diagnosed with SLE were enrolled into the study group and 31 healthy individuals (56 eyes) into the control group. Vessel density reduction in parafovea, inferior and nasal quadrants of superficial retinal capillary plexus in a cohort of SLE patients was found. Among study group kidney involvement was associated with further microvasculature reduction. Knowing that retinal involvement may precede other organs impairment, early detection of retinal impairment and use of OCTA as a screening modality, may decrease overall disease morbidity.

Subclinical Retinal Capillary Abnormalities in Juvenile Systemic Lupus Erythematosus without Ocular Involvement

PURPOSE

This study aimed to evaluate subclinical retinal microvascular changes with OCTA in juvenile systemic lupus erythematosus (JSLE) patients without ocular involvement.

METHODS

Ten eyes of 10 JSLE and 13 eyes of 13 age and sex-matched healthy controls (HCs) were enrolled. The superficial (SCP) and deep capillary plexus (DCP), FAZ parameters, the flow area of the outer retina, and choriocapillaris were evaluated using OCTA.

RESULTS

All vessel density (VD) parameters in DCP were significantly lower in JSLE group compared to HCs. There was no significant difference between the groups in VD parameters of both SCP and ONH, FAZ, outer retina and choriocapillaris flow area. All DCP VD parameters showed a good ability to differentiate JSLE from HCs.

CONCLUSION

OCTA could detect retinal vascular impairment in the deep macular region in JSLE patients with normal ocular examination. Furthermore, all DCP VD parameters have a good ability to discriminate JSLE from HCs.

Choriocapillaris Flow Deficits Quantification in Hydroxychloroquine Retinopathy Using Swept-Source Optical Coherence Tomography Angiography

This study aims to quantitatively analyze choriocapillaris (CC) alterations using swept-source optical coherence tomography angiography (SS-OCTA) in eyes presenting with hydroxychloroquine (HCQ) toxic retinopathy and to compare it to patients under HCQ without toxic retinopathy and to healthy controls. For image analysis, CC en-face slabs were extracted from macular 6 × 6 mm SS-OCTA scans and a compensation method followed by the Phansalkar local thresholding was performed. Percentage of flow deficits (FD%) and other related biomarkers were computed for comparison. Fourteen eyes (7 patients) presenting with HCQ toxic retinopathy, sixty-two eyes (31 patients) under HCQ without signs of toxicity, and sixty eyes of 34 healthy controls were included. With regards to FD%, FD average size, and FD number there was a significant difference between the three groups (p < 0.05 with radius 4 and radius 8 pixels). Eyes presenting with HCQ toxicity had significantly higher FD% and average size, and a significantly lower number of FDs, with both radius 4 and 8 pixels. In conclusion, FD quantification demonstrates that CC involvement is present in HCQ toxic retinopathy, therefore giving pathophysiological insights with regards to the CC as being either the primary or secondary target of HCQ toxicity.

Evaluation of subclinical ocular involvement in patients with deficiency of adenosine deaminase 2 (DADA2)

PURPOSE

To evaluate changes in the peripapillary, macular, and choroidal microvasculature in the eyes of patients with deficiency of adenosine deaminase 2 (DADA2) and no clinical signs of ocular involvement.

METHODS

The study included 12 eyes of 12 patients with DADA2 and 24 eyes of 24 healthy subjects. The foveal avascular zone (FAZ), macular vessel densities (VDs) in the superficial and deep retinal capillary plexuses, peripapillary VDs, and choroidal thickness were evaluated by optical coherence tomography angiography (OCTA). Measurements were compared between DADA2 patients and healthy controls.

RESULTS

The median age was 17 (8-25) years in DADA2 patients and 17.5 (7-23) years in control group at the OCTA visit (p = 0.934). FAZ area did not differ between the groups (p = 0.224). In the superficial capillary plexus, whole-image, foveal, and parafoveal VD values were slightly lower in DADA2 patients than in controls (p = 0.054, p = 0.052, p = 0.117). In the deep capillary plexus, whole-image and parafoveal VD values were significantly lower in DADA2 patients than controls (p = 0.010, p = 0.001). VD in the radial peripapillary capillary plexus was also lower in DADA2 patients, with significantly lower peripapillary VD (p = 0.002). Subfoveal choroidal thickness was significantly higher in patients with DADA2 (p < 0.001).

CONCLUSIONS

This OCTA study demonstrates that both retinal and choroidal involvement may occur in DADA2 patients before the emergence of evident clinical findings.

Evaluation of subclinical retinal microvascular changes in systemic lupus erythematosus patients using optical coherence tomography angiography and its relationship with disease activity

Objective

This study aimed to investigate subclinical retinal microvascular changes with optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE) and healthy controls (HCs), and to evaluate the relationship between OCTA findings and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K).

Materials and Methods

In this study, 47 eyes of SLE and 41 eyes of healthy control (HC) were evaluated. The SLE patients were divided into two subgroups: low disease activity (LDA) (SLEDAI≤5) and high disease activity (HDA) (SLEDAI>6). The results of OCTA were compared between SLE patients and HCs as well as the SLE subgroups. The relationship between OCTA results and SLEDAI-2K was evaluated.

Results

There were no differences in foveal avascular zone (FAZ) areas between the SLE patients and HCs. Central foveal thickness (CFT) was lower in SLE patients ( p = .046). Superficial capillary plexus (SCP) vessel density (VD) in SLE patients was significantly lower only in the foveal area compared to that in HCs ( p = .006). Deep capillary plexus (DCP) VD in SLE patients was significantly lower in all areas except the temporal parafoveal area compared to that in the HCs. There was no statistically significant difference between SLE groups with LDA and HDA in FAZ or any of the other areas, including SCP and DCP. When the correlation between OCTA findings and SLEDAI-2K was examined, both SCP and DCP VD were found to be negatively correlated.

conclusions

It was observed that DCP VDs were affected in SLE patients with LDA, and SCP VDs were also affected in addition to DCP with HDA. This suggests that DCP may be the first capillary plexus to be comprised in SLE. VDs were negatively correlated with disease activity. It was concluded that OCTA can be a useful tool in assessing subclinical retinal microvascular pathology and disease activity in patients with SLE.

New insights in pathogenic mechanism of hydroxychloroquine retinal toxicity through optical coherence tomography angiography analysis

INTRODUCTION

There is only a unique report with a small sample size studying hydroxychloroquine (HCQ) retinal toxicity with swept-source (SS) optical coherence tomography angiography (OCTA). The aim of this study was to quantify OCTA quantitative parameters in patients who underwent HCQ therapy.

METHODS

We conducted a retrospective study. The study included 43 eyes of 22 patients taking HCQ for more than 5 years (high-risk group), 57 eyes of 29 patients taking HCQ for 5 years or less (low-risk group) and 25 eyes of 50 age-matched healthy controls. OCTA quantitative parameters (vessel density (VD) and foveal avascular zone (FAZ) area in superficial capillary plexus (SCP), middle capillary plexus (MCP), deep capillary plexus (DCP), total capillary plexus (TCP), and choriocapillaris (CC)) were recorded.

RESULTS

In the low-risk group, VD in the SCP and MCP was increased compared to control group (p value <.05). In the high-risk group, VD in the SCP, MCP and TCP was increased (p value <.05). The subgroup analysis revealed an increased VD at SCP in systemic lupus erythematosus (SLE) high-risk patients, an increased VD at TCP and CC in rheumatoid arthritis (RA) high-risk subjects, and a decreased VD at CC level in the high-risk group patients with Sjögren's syndrome (SS) and connective tissue disease (CTD) (p value <.05). Furthermore, we demonstrated a significant enlargement of FAZ area at MCP level in the high-risk group patients with SS and CTD (p value <.05).

CONCLUSION

We demonstrated an increase of VD in patients who underwent HCQ treatment, so we suggest that HCQ retinal toxicity is not vascular mediated.

Optical coherence tomography angiography in primary eye care

Optical coherence tomography angiography (OCT-A) is a non-invasive imaging modality for assessing the vasculature within ocular structures including the retina, macula, choroid and optic nerve. OCT-A has a wide range of clinical applications in various optometric conditions which have been independently reported in the literature. This paper aims to present a review of the current literature on the clinical application of OCT-A in optometric practice as well as to analyse and evaluate the quality of the available evidence. This review included 78 articles from a literature search conducted on 26 May 2019 across the following databases: Cochrane Library of Systematic Reviews, Medline, Scopus and Web of Science. Primary ocular pathologies discussed in this review include glaucoma, diabetic retinopathy, age-related macular degeneration, myopia, acquired and congenital macular dystrophies, epiretinal membrane, retinal vein occlusion, retinitis pigmentosa, choroidal melanoma, uveitis, central serous chorioretinopathy, amblyopia and optic neuropathies. Primary outcome variables included vessel density, foveal avascular zone area and diameter, flow velocity and flow index. This review aims to evaluate the evidence available for OCT-A applications in diagnosis and prognosis of ocular conditions in an optometric setting.

OCT retinal angiography features in patients with rheumatoid arthritis: A pilot study

PURPOSE

To evaluate the superficial (SCP) and deep retinal capillary plexus (DCP) by mean of optical coherence tomography angiography (OCTA) in treatment-naïve patients affected by rheumatoid arthritis (RA).

METHODS

Between March 2019 and January 2020, patients with recent diagnosis of "definite RA" based on 2010 Rheumatoid Arthritis Classification Criteria were included in a Prospective, observational single center case-control study carried out at G.B. Bietti Foundation. Data were compared with those of 16 healthy age- and sex-matched subjects. Values of the vessel density (VD) of SCP and DCP, central foveal thickness (CFT), foveal avascular zone (FAZ) were collected by mean of OCTA. Main outcome measure was the VD alteration of SCP and DCP in treatment-naïve RA-patients.

RESULTS

No difference in age, sex-distribution, best-corrected visual acuity, CFT was registered between the two groups. OCTA data analysis showed in RA-patients a statistically significant reduction in the VD in the mean global area, inner ring, especially in the superior quadrant of the SCP. A trend of VD reduction was also registered in temporal, nasal, and inferior quadrants, respectively, although it did not reach a statistically significant value. Assessment of VD of DCP and FAZ area did not evidence any difference among the groups.

CONCLUSIONS

OCTA allows to highlight the vascular remodeling of the retinal microcirculation in RA-patients, even in early stages of the disease, demonstrating a reduction of VD. Outcomes of the current investigation can provide new insight in the pathogenetic mechanism of RA and extend the potential applications of this diagnostic tool.

Optical Coherence Tomography Angiography as a New Tool for Evaluation of the Subclinical Retinal Involvement in Patients with Systemic Lupus Erythematosus-A Review

Knowing the proven relationship between lupus retinopathy and systemic changes and disease activity, it is crucial to find the possibility of early diagnosis of retinal changes at a subclinical level in order to provide faster medical intervention and protect the patient from irreversible changes in the eye and other organs. The aim of this review is an analysis of studies investigating early pathological changes in retinal vascularization obtained by optical coherence tomography angiography (OCTA) and their relationship to the systemic lupus erythematosus (SLE). A literature search was performed to identify all relevant articles, regarding detection of subclinical retinal changes using OCTA in systemic lupus erythematosus listed in PubMed database. Seven out of seven papers found showed a decrease in superficial capillary plexus in ocular asymptomatic patients diagnosed with SLE. A decrease in retinal vessel density measured by OCTA may be a good marker of SLE activity and poor prognosis. OCTA in a safe manner can give clinicians a new perspective on processes of vessel remodeling and answer the question of how SLE might impact the eye from a structural point of view. Adding OCTA to the standard diagnostic process of SLE patients, may detect systemic changes early and prevent further visual deterioration by stopping progression of lupus retinopathy.

Evaluation of optical coherence tomography angiography parameters in patients treated with Hydroxychloroquine

Background

One of the major side effects of Hydroxychloroquine (HCQ) is retinopathy. The aim of this study was to evaluate the Optical coherence tomography angiography (OCTA) parameters in a group of patients who have Hydroxychloroquine-induced retinopathy based on Multifocal electroretinography (mfERG) with a group who do not have retinopathy.

Method

This is a Cross-Sectional Study. In this study, patients with Rheumatoid arthritis (RA) or Systemic lupus erythematosus (SLE) who had been taking Hydroxychloroquine for at least 7 years were included. MfERG and OCTA imaging were performed for all patients. Patients were divided into Normal mfERG and Abnormal mfERG groups based on mfERG results. OCTA parameters were studied in these two groups.

Result

Sixty-one patients (61 eyes) were included. Forty-one patients had SLE and 20 patients had RA. Forty patients (66.7%) had Abnormal mfERG. The mean vascular density (VD) in Superficial capillary plexus (SCP) layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). Mean VD in SCP layer was not significantly different between Normal mfERG and Abnormal mfERG groups (P-Value> 0.05). In RA subgroup, mean VD in SCP layer in PeriFovea region in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). Mean VD in deep capillary plexus (DCP) layer in Whole Image, Superior Hemi, Inferior Hemi, PeriFovea area in Abnormal mfERG group was significantly lower than normal group (P-Value < 0.05). This discrepancy was also observed in the RA subgroup but not in the SLE subgroup. The mean of none of the parameters of foveal avascular zone (FAZ) (mm2), Flow Area of Outer Retina (mm2) and Flow Area of Choriocapillaris (mm2) were not statistically significant between the groups Abnormal mfERG and Normal mfERG. (p-value> 0.05).

Conclusion

VD in the DCP layer decreased in abnormal mfERG patients compared to patients with normal mfERG. But it seems that VD in SCP layer, FAZ Area and Flow Area are similar in both groups. OCTA may be used as a non-invasive tool in the diagnosis of early stages of HCQ-induced retinopathy, especially in RA patients, but further studies are needed.

Changes in parafoveal and peripapillary perfusion after decompression surgery in chiasmal compression due to pituitary tumors

We evaluated changes in parafoveal and peripapillary vessel density in chiasmal compression after decompression surgery using optical coherence tomography angiography (OCT-A). Sixty-two eyes with chiasmal compression for which preoperative and postoperative (4–6 months) OCT, OCT-A, visual field (VF), and comprehensive ophthalmic data were available, and 44 healthy eyes were evaluated. Vessel densities of the superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and radial peripapillary capillary (RPC) segment were assessed using OCT-A. The postoperative measurements were compared with preoperative data. Preoperative peripapillary retinal nerve fiber layer, macular ganglion cell-inner plexiform layer thickness, and vessel densities of SRCP and RPC segments in patients’ eyes were significantly reduced compared to those of healthy controls (P < 0.0001, P < 0.0001, P = 0.0052, and P = 0.0085, respectively). Vessel densities were significantly decreased in the SRCP (P < 0.0001), DRCP (P = 0.0017), and RPC segments (P < 0.0001) after surgery compared to the preoperative values. Significant associations between the postoperative SRCP and DRCP vessel density changes and preoperative SRCP (r =  − 0.3195, P = 0.0114) and DRCP (r =  − 0.5165, P < 0.0001) vessel densities were found, respectively. There were also significant associations between postoperative SRCP vessel density changes and VF changes (r =  − 0.2586, P = 0.0424). These findings indicate that decreased perfusion around the optic nerve head and on the macula associated with chiasmal compression could further progress after decompression surgery. Further functional and longer-term clinical studies are needed to elucidate the clinical implications of these findings.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Evaluation of the different thresholding strategies for quantifying choriocapillaris using optical coherence tomography angiography

Background

In this paper, we evaluate the different thresholding strategies that have been used for the quantification of the choriocapillaris (CC) and explore their repeatability and the interchangeability of the measurements resulting from its application.

Methods

Observational study. Eighteen eyes from nine healthy volunteers aged >18 years were imaged four consecutive times with a SD-OCTA system (Heidelberg Engineering, Germany) using a 10°×10° high-resolution protocol centered on the fovea. Projection artifacts were removed, and the CC was bracketed between 10 and 30 µm below Bruch's membrane. For the quantification of CC, we used four flow deficits (FD) parameters: FD number, mean FD size, total FD area and FD density. We performed a systematic review of literature to collect the thresholding methods that have been used for the quantification of CC. The CC quantification parameters were then evaluated after applying each of the thresholding strategies. Intraclass correlation coefficient (ICC) and Pearson's correlation analysis were used to compare the repeatability and interchangeability among the different thresholding strategies for quantifying the CC.

Results

A total of 72 optical coherence tomography angiography (OCTA) examinations were considered. The systematic review allowed us to conclude that three local thresholding strategies (Phansalkar, mean and Niblack) and three global thresholding strategies (mean, default, Otsu) have been used for CC quantification. These strategies were evaluated in our observational study. We found a high agreement within the same method in the quantification of FD number, mean FD size, total FD area and FD density but a poor agreement with different strategies. Local strategies achieved a significantly superior ICC than global ones in CC quantification.

Conclusions

In conclusion, the interchangeability of the CC quantification using different thresholding strategies is low, and direct comparisons should not be performed. Local thresholding strategies are significantly superior to global ones for quantifying CC and should be preferred. There is an unmet need for a uniform strategy to quantify CC in future studies.

Is optical coherence tomography angiography a useful tool in the screening of hydroxychloroquine retinopathy?

PURPOSE

To detect the early changes in retinal vasculature via optical coherence tomography angiography (OCTA) by comparing the quantitative OCTA parameters in the group of patients who were using hydroxychloroquine (HCQ) or not.

METHODS

This was a cross-sectional, comparative, and observational study. The patients who were newly or previously prescribed HCQ for an autoimmune disease were included. OCTA imaging was performed via OCT RT XR Avanti with AngioVue software (Optivue Inc, Freemont, CA). The study group had two groups: a control group (patients newly diagnosed and who were not taking any medication) and a treatment group (patients who were receiving HCQ treatment). The main outcome measure was OCTA parameters.

RESULTS

A total of 102 eyes of 102 patients were included. There were 70 patients in the treatment group and 32 patients in the control group. All of the vascular density values were similar between the control and treatment groups (p > 0.05 for all). However, the superficial whole thickness, superficial parafoveal thickness, superficial perifoveal thickness, deep whole thickness, deep parafoveal thickness, and deep perifoveal thickness were thinner in the treatment group than the control group (p < 0.05 for all).

CONCLUSION

Vascular density parameters did not differ between the control and treatment groups. However, the retinal thickness values were lower in the treatment group.

Altered microvascular density in patients with systemic lupus erythematosus treated with hydroxychloroquine-an optical coherence tomography angiography study

Purpose

To evaluate the retinal microvascular density using optical coherence tomography angiography (OCTA) in patients with systemic lupus erythematosus (SLE) treated with hydroxychloroquine (HCQ).

Methods

Nineteen eyes of 19 patients with SLE (study group) without HCQ retinopathy and 19 eyes of 19 healthy subjects (control group) were included in this study. The study group was divided into patients using HCQ for > 5 years (high-risk group) and < 5 years (low-risk group). The VD data of the 3 × 3 mm OCT angiogram of the superficial capillary plexus (SCP) and the choriocapillaris (VD-CC), the foveal avascular zone (FAZ) area and the central retinal thickness (CRT) were extracted and analyzed.

Results

VD in the en face SCP was significantly reduced in the high-risk group and the low-risk group compared with that in the control group (p < 0.001, p = 0.001) and in the high-risk group compared with the low-risk group (p = 0.007). Correlation analysis between the cumulative dose of HCQ and the VD of the study group revealed a negative correlation, but no statistical significance (p = 0.074). However, a significant positive correlation was observed for the low-risk group (p = 0.035). In patients with SLE, VD-CC was lower (p = 0.042) and the FAZ area larger (p = 0.019). CRT showed no difference between the groups (p = 0.183).

Conclusion

In this study, SLE patients showed a reduced VD in both groups. In patients treated with HCQ < 5 years, HCQ might have a protective effect on retinal microvasculature. Analysis of retinal microvascular density using OCTA could be useful in the diagnosis and monitoring of vascular alteration in patients with SLE.

Swept-source optical coherence tomography imaging of the retinochoroid and beyond

Introduction: Swept-source optical coherence tomography (SS-OCT) imaging has ushered in an era of rapid and high-resolution imaging of the retinochoroid that provides detailed patho-anatomy of various layers.Areas covered: In this detailed review, the technology of swept-source imaging including its principles and working has been discussed. The applications of SS-OCT in various conditions including age-related macular degeneration, diabetic retinopathy, pachychoroid spectrum of diseases, and inflammatory vitreoretinal conditions have been elaborated. For each disease, a brief review of literature along with the utility of SS-OCT and optical coherence tomography angiography has been provided with supporting figures. The advantages of SS-OCT over spectral-domain have been discussed if there is sufficient evidence in the literature. Finally, the review summarizes the technological advantages in this field of retinal imaging.Expert opinion: The introduction of SS-OCT in our clinics has added newer devices in our armamentarium that can provide high-quality images of the deep retina and choroid. These advances in medical devices can help in improving our knowledge relating to the pathophysiology of diseases and their evolution. In the near future, rapid and high-resolution imaging may provide real-time volumetric information of the whole retina and the choroid that can be readily used for patient care.

Parafoveal and Peripapillary Perfusion Predict Visual Field Recovery in Chiasmal Compression due to Pituitary Tumors

Background: To evaluate the potential of vessel density alterations for predicting postoperative visual field (VF) improvement in chiasmal compression using optical coherence tomography angiography (OCT-A). Methods: The study investigated 57 eyes of 57 patients diagnosed with pituitary tumors and 42 eyes of 42 age and refractive error matched controls. All eyes with chiasmal compression for which preoperative optical coherence tomography (OCT) and OCT-A, and pre- and postoperative VF data were available. Preoperative vessel densities of superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and radial peripapillary capillary (RPC) segment were utilized by OCT-A. Results: Preoperative peripapillary retinal nerve fiber layer and ganglion cell layer complex thickness and vessel densities of SRCP and RPC segments in eyes with chiasmal compression were significantly reduced compared with healthy controls (p < 0.001, p < 0.001, p = 0.007, and p = 0.020, respectively). In multivariate regression analysis, preoperative perimetric mean deviation (MD) (p = 0.002) and vessel density of SRCP (p = 0.025) were correlated significantly with postoperative perimetric MD. Spearman’s correlation analysis revealed significant correlations between preoperative MD on perimetry (r = 0.443, p = 0.001), vessel densities of SRCP (r = 0.288, p = 0.035) and RPC segment (r = 0.347, p = 0.009), and postoperative perimetric MD. Conclusions: Structural degeneration referred to as microvascular alterations measured by OCT-A and preoperative VF defects were associated with worse postoperative VF prognosis. Parafoveal and peripapillary vessel densities may serve as a sensitive, structural prognostic factors in the preoperative judgement of chiasmal compression.

Analysis of Optic Chiasmal Compression Caused by Brain Tumors Using Optical Coherence Tomography Angiography

We have quantitatively evaluated the macular and peripapillary microvascular changes in eyes with chiasmal compression caused by brain tumors compared with healthy control eyes using optical coherence tomography angiography (OCT-A) and correlated them with other ocular parameters. This cross-sectional study involved the analysis of 36 eyes of 36 patients with chiasmal compression and age and refractive error-matched 35 healthy control eyes. OCT-A was used to generate microvascular images of the superficial and deep retinal capillary plexus (SRCP, DRCP) and the radial peripapillary capillary (RPC) segment in the macula and peripapillary areas. Automated segmentation and vessel density measurements facilitated the analysis of each layer. Macular OCT-A analysis revealed a significant reduction in vessel density in the SRCP (P = 0.004) of the nasal quadrant (P < 0.001) and in the same quadrant of the DRCP (P = 0.019) in the eyes with chiasmal compression compared with the control eyes. The RPC segment vessel density has also been significantly reduced in the eyes with chiasmal compression (P < 0.001). The RPC segment and the SRCP vessel densities were correlated with the peripapillary retinal nerve fiber layer and the ganglion cell layer complex thicknesses. The RPC segment and the nasal quadrant SRCP and the DRCP vessel densities were correlated with visual field defect. Significant microvascular alterations have been detected in the eyes with chiasmal compression compared with the control eyes. This study confirmed that chiasmal compression caused by brain tumors not only induced a loss of ganglion cells but also resulted in intra-retinal microvascular changes.