Changes in peripapillary choroidal thickness in patients with multiple sclerosis

Evaluation of choroidal thickness and retinal nerve fiber layer thickness in Chinese pregnant women and healthy non-pregnant women

Purpose

To evaluate choroidal thickness and retinal nerve fiber layer (RNFL) thickness in different trimesters using enhanced depth imaging optical coherence tomography (EDI-OCT).

Methods

A prospective comparative study included 45 healthy pregnant women in the first trimester, 45 women in the second, 45 women in the third and 45 healthy non-pregnant women as the control group. Macular choroidal thickness was measured at three locations: The subfoveal, 1 ​mm temporal, and 1 ​mm nasal from the fovea with EDI-OCT. Peripapillary choroidal thickness (PPCT) and RNFL thickness parameters were automatically calculated by the Spectralis OCT.

Results

The subfoveal, temporal and nasal macular choroidal thickness were all significantly thicker in the second trimester, compared with those parameters in the first, the third trimesters and the control group (all P ​< ​0.05). The PPCT was significantly increased in the second trimeter compared with the control group at global, temporal, temporal inferior, nasal and nasal inferior positions (all P ​< ​0.05). The RNFL thickness was also significantly increased in pregnant women at nasal superior and nasal inferior quadrants (all P ​< ​0.05).

Conclusions

The choroidal thickness in pregnant women was found to be thicker than the control group, regardless of macular or optic disc location. Findings of RNFL thickening might indicate subclinical involvement of the central nervous system.

Impact of obesity on peripapillary choroidal thickness, macular choroidal thickness, and lamina cribrosa morphology

BACKGROUND

Obesity is known to be a significant risk factor for many ocular diseases. In order to understand the mechanism of obesity-related ocular diseases, we examined the lamina cribrosa morphology, peripapillary choroidal thickness (PPCT), and macular choroidal thickness (MCT) in obese women using optical coherence tomography (OCT).

METHODS

This comparative cross-sectional study included the right eyes of 72 obese women and 63 healthy women classified based on body mass index (BMI). Each participant underwent a thorough ophthalmological examination and enhanced depth (EDI) OCT imaging, including measurements of PPCT from a total of 12 regions, MCT from a total of 7 regions, Bruch's membrane opening (BMO), lamina cribrosa thickness (LCT), lamina cribrosa depth (LCD), intraocular pressure (IOP), and central corneal thickness (CCT).

RESULTS

The mean age and BMI of the obese group were 32.36±7.38 years and 35.11±4.39 kg/m², while those of the control group were 31.64±7.78 years and 20.88±1.72 kg/m² (p = 0.658, and p<0.001, respectively). PPCT N1000, PPCT N1500, PPCT S1500, and PPCT T1500 were statistically significantly thinner in the obese group than the control group (p values were 0.039, 0.012, 0.027, and 0.036, respectively). IOP and CCT were significantly higher in the obese group than the control group (p = 0.016, and p = 0.019, respectively). There was no statistically significant difference between the two groups in terms of MCT, BMO, LCT, and LCD.

CONCLUSION

We discovered thinning in the PPCT, which indicates microvascular abnormalities in the optic disc head. Microvascular alteration in the peripapillary region may be a potential initial event in the pathogenesis of several obesity-related ocular diseases, especially glaucoma.

Optical coherence tomography as retinal imaging biomarker of neuroinflammation/neurodegeneration in systemic disorders in adults and children

The retina and the optic nerve are considered extensions of the central nervous system (CNS) and thus can serve as the window for evaluation of CNS disorders. Spectral domain optical coherence tomography (OCT) allows for detailed evaluation of the retina and the optic nerve. OCT can non-invasively document changes in single retina layer thickness and structure due to neuronal and retinal glial cells (RGC) modifications in systemic and local inflammatory and neurodegenerative diseases. These can include evaluation of retinal nerve fibre layer and ganglion cell complex, hyper-reflective retinal spots (HRS, sign of activated microglial cells in the retina), subfoveal neuroretinal detachment, disorganization of the inner retinal layers (DRIL), thickness and integrity of the outer retinal layers and choroidal thickness. This review paper will report the most recent data on the use of OCT as a non invasive imaging biomarker for evaluation of the most common systemic neuroinflammatory and neurodegenerative/neurocognitive disorders in the adults and in paediatric population. In the adult population the main focus will be on diabetes mellitus, multiple sclerosis, optic neuromyelitis, neuromyelitis optica spectrum disorders, longitudinal extensive transverse myelitis, Alzheimer and Parkinson diseases, Amyotrophic lateral sclerosis, Huntington's disease and schizophrenia. In the paediatric population, demyelinating diseases, lysosomal storage diseases, Nieman Pick type C disease, hypoxic ischaemic encephalopathy, human immunodeficiency virus, leukodystrophies spinocerebellar ataxia will be addressed.

Choroidal Thickness in Multiple Sclerosis: An Optical Coherence Tomography Study

Background and Purpose

To identify changes in the choroidal thickness (CT) in multiple sclerosis (MS) patients with and without optic neuritis (ON) using enhanced-depth-imaging optical coherence tomography (EDI-OCT).

Methods

This cross-sectional study included 96 eyes with MS and 28 eyes of healthy controls. All participants underwent an ophthalmologic examination and EDI-OCT scanning (Spectralis, Heidelberg Engineering, Germany) to assess the CT and the retinal nerve fiber layer (RNFL) thickness. MS patients were divided into two groups: 1) with and 2) without a history of ON. The CT was evaluated in the fovea and at six horizontal and six vertical points at 500, 1,000, and 1,500 µm from the fovea. Paired t-tests were used to compare the groups, and p-value<0.05 was considered as significant.

Results

At all 13 measurements points, the CT was thicker in MS patients than in the healthy controls and was thinner in eyes with ON than in the contralateral eyes, but these differences were not statistically significant. However, the CT was always larger in all points in eyes with a history of ON than in the control eyes. The RNFL was significantly thinner (p<0.05) in both MS and ON eyes than in the control eyes.

Conclusions

The CT did not differ between MS and control eyes, but it was significantly larger in patients with a history of ON, in whom the RNFL was thinner. Further studies are necessary to establish the possible role of the choroid in MS.

Evaluation of peripapillary and subfoveal choroidal vascularity index in patients with multiple sclerosis

PURPOSE

To evaluate the changes in the peripapillary choroidal vascularity index (PCVI) and subfoveal choroidal vascularity index (SFCVI) in multiple sclerosis (MS) patients and healthy subjects METHODS: A total of 145 eyes of 73 patients were investigated in this cross-sectional study. 78 eyes of 39 MS patients (Group 1) and 67 eyes of 34 healthy subjects (Group 2) were evaluated. MS patients with a history of optic neuritis (ON) constituted Group 1a, those without a history of ON constituted Group 1b.

RESULTS

The mean PCVI was significantly lower in Group 1 than Group 2 (61,39±3,00 % vs 64,49±2,29 % respectively, p<0.001). The mean SFCVI scores of Group 1 was significantly lower than Group 2 (64,01±2,66 % vs. 66,87±2,14 % respectively, p<0.001). The mean PCVI of Group 1a (59,26±2,85 %) was significantly lower compared to Group 1b (62,87±2,08 %) and Group 2 (64,49±2,29 %, p1<0.001, p2<0.001). The mean SFCVI of Group 1a was significantly lower than Group 2 (64.26±2.75 % vs. 66.87±2.14 % respectively, p<0.001).

CONCLUSION

PCVI and SFCVI scores were significantly lower in MS patients compared to healthy controls. PCVI scores of MS patients who had a history of ON were significantly lower than those of patients without a previous ON attack, as were SFCVI scores. We consider that evaluation of PCVI and SFCVI might be useful for monitoring ocular involvement in patients with MS.

Choroidal Thickness Profile in Chorioretinal Diseases: Beyond the Macula

Enhanced depth imaging optical coherence tomography (EDI-OCT) and swept-source OCT (SS-OCT) have emerged as essential diagnostic tools in the study and management of various chorioretinal diseases. Evidence from early clinical studies using EDI-OCT and SS-OCT indicates that choroidal dysfunction plays a major role in the pathogenesis of chorioretinal diseases. Measurement of choroidal thickness (CT) has already become a major research and clinical method, and CT is considered as an indicator of choroidal status in a variety of ophthalmic diseases. Recently, CT measurement has also been proposed as a non-invasive marker for the early detection and monitoring of various systemic diseases. Among the several possible CT measurement locations, subfoveal CT has rapidly become a reliable parameter for measuring CT in healthy and diseased eyes. Moreover, recent advancements in OCT technology have enabled faster and wider imaging of the posterior part of the eye, allowing the various changes in CT as measured outside the macula to be shown accordingly. In this review, we first provide an overview of the results of clinical studies that have analyzed the healthy macular choroid and that in various chorioretinal diseases, and then summarize the current understanding of the choroid outside the macula. We also examine the CT profile as an index that encompasses both within and outside of the macula. Furthermore, we describe the clinical applications of ultrawide OCT, which enables visualization of the far periphery, and discuss the prospects for the development of more reliable choroidal parameters that can better reflect the choroid's characteristics.

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.

Angiography with optical coherence tomography as a biomarker in multiple sclerosis

PURPOSE

To investigate superficial retinal microvascular plexuses detected by optical coherence tomography angiography (OCT-A) in multiple sclerosis (MS) subjects and compare them with healthy controls.

METHODS

A total of 92 eyes from 92 patients with relapsing-remitting MS and 149 control eyes were included in this prospective observational study. OCT-A imaging was performed using Triton Swept-Source OCT (Topcon Corporation, Japan). The vessel density (VD) percentage in the superficial retinal plexus and optic disc area (6 x 6 mm grid) was measured and compared between groups.

RESULTS

MS patients showed a significant decrease VD in the superior (p = 0.005), nasal (p = 0.029) and inferior (p = 0.040) parafoveal retina compared with healthy subjects. Patients with disease durations of more than 5 years presented lower VD in the superior (p = 0.002), nasal (p = 0.017) and inferior (p = 0.022) parafoveal areas compared with healthy subjects. Patients with past optic neuritis episodes did not show retinal microvasculature alterations, but patients with an EDSS score of less than 3 showed a significant decrease in nasal (p = 0.024) and superior (p = 0.006) perifoveal VD when compared with healthy subjects.

CONCLUSIONS

MS produces a decrease in retinal vascularization density in the superficial plexus of the parafoveal retina. Alterations in retinal vascularization observed in MS patients are independent of the presence of optic nerve inflammation. OCT-A has the ability to detect subclinical vascular changes and is a potential biomarker for diagnosing the presence and progression of MS.

Early diagnosis of multiple sclerosis by OCT analysis using Cohen's d method and a neural network as classifier

BACKGROUND

The consequences of inflammation, demyelination, axonal degeneration and neuronal loss in the central nervous system, typical of the development of multiple sclerosis (MS), are manifested in thinning of the retina and optic nerve. The purpose of this work is to diagnose early-stage MS patients based on analysis of retinal layer thickness obtained by swept-source optical coherence tomography (SS-OCT).

METHOD

OCT (Triton® SS-OCT device -Topcon, Tokyo, Japan-) recordings were obtained from 48 control subjects and 48 recently diagnosed MS patients. The following thicknesses were measured on a 45 × 60 grid: retinal nerve fibre layer (RNFL), ganglion cell layer (GCL+), GCL++, retinal thickness and choroid. Using Cohen's d effect size, it was determined the regions and layers with greatest capacity to discriminate between control subjects and patients. Points exceeding the threshold set were used as inputs for an automatic classifier: support vector machine and feed-forward neural network.

RESULTS

In MS at clinical onset the layer with greatest discriminant capacity is GCL++ [AUC = 0.83] which exhibits a horseshoe-like macular topographic distribution. It is followed by retina, GCL+ and RNFL; choroidal thicknesses do not provide discriminatory capacity. Using a neural network as a classifier between controls and MS patients, obtains sensitivity of 0.98 and specificity of 0.98.

CONCLUSIONS

This work suggest that OCT may serve as an important complementary role to other clinical tests, particularly regarding neurodegeneration. It is possible to characterise structural alterations in retina and diagnose early-stage MS with high degree of accuracy using OCT and artificial neural networks.

Optical coherence tomography angiography in multiple sclerosis: A cross-sectional study

OBJECTIVES

To evaluate retinal axonal density and retinal capillary flow density (CFD) variations in patients affected by multiple sclerosis (MS) as documented by Optical Coherence Tomography Angiography (OCT-A).

MATERIAL AND METHODS

A cross-sectional study was performed in a tertiary university eye hospital on 94 eyes from 48 MS patients compared to 37 eyes from 23 matched controls. MS patients were divided in two groups: those with previous episodes of optic neuritis (MS ON+, 71.4%) and those without any previous visual complaint (no optic neuritis group, MS ON, 28.6%). Patients underwent macular and optic nerve head OCT-A with Optovue XR Avanti (Optovue, Freemont, California) after that preliminary evaluation of the ganglion cell complex (GCC) and of the retinal nerve fiber layer (RNFL) was achieved for each single eye by SD-OCT. CFD was evaluated in three different retinal layers of MS patients and controls: superficial capillary plexus (SCP), deep capillary plexus (DCP) and the choriocapillaris layer (CL). Each layer was analyzed in 18 preset subregions automatically detected by the system. CFD values were then correlated to the RNFL thickness and GCC thickness in the groups: p values were computed by t-tests between each group of MS patients and controls. A p-value of <0.05 was considered significant.

RESULTS

A significant difference in the overall CFD values was found between ON+ and ON- patients when compared to controls in 18 subregions of SCP. Furthermore, a significant difference was found between MS patients and controls in 16 subregions analyzed corresponding to the CL layer without difference between the two MS subgroups (ON+ and ON-).

CONCLUSIONS

OCT-A when performed at the optic nerve head level and at the macular region is characterized by a reduction of retinal perfusion in a significant portion of MS patients independently if they had a previous history of optic nerve inflammation or not.