Optical coherence tomography in the diagnosis of scleritis and episcleritis

Lycium barbarum L. and Salvia miltiorrhiza Bunge extract ameliorates retinitis pigmentosa in rd10 mice by affecting endoplasmic reticulum stress

ETHNOPHARMACOLOGICAL RELEVANCE

Lycium barbarum L. and Salvia miltiorrhiza Bunge (Gouqi and Danshen, LS) have led to their inclusion in the pharmacopoeia and healthcare systems of numerous countries globally. Traditional herbs known as LS are used in China to treat retinitis pigmentosa (RP). However, the mechanism is not clear.

AIM OF THE STUDY

This study is to investigate the mechanism by which LS improves RP using rd10 mice as a model.

MATERIALS AND METHODS

LS extract was used to treat the rd10 mice for four weeks. Fundus photographs, optical coherence tomography, electroretinography, histopathological examination, TUNEL apoptosis assay, digital PCR analysis, western blotting, and immunofluorescence double staining were performed.

RESULTS

The outer nuclear layer (ONL) thickness of the retina was significantly increased by the LS extract, improving atrophy, and both the ONL and the retinal pigment epithelium (RPE) layer were visible. Following treatment with LS extract, there was a notable increase in the magnitudes of ERG a- and b-waves in the retina, along with a significant reduction in the quantity of TUNEL-positive cells. Additionally, LS extract significantly reduced the levels of ER stress-related factors in rd10 mice. The results of immunofluorescence double staining further confirm that LS extract inhibits the GRP78/PERK/ATF4/CHOP pathway.

CONCLUSION

In this study, the protective effects of LS extract on the retina were uncovered, suggesting that its mechanism could involve decreasing retinal cell apoptosis through the inhibition of the ER stress pathway.

Biometry-Based Technique for Determining the Anterior Scleral Thickness: Validation Using Optical Coherence Tomography Landmarks

Purpose

Considering the potential role of anterior scleral thickness (AST) in myopia and the ubiquitous use of optical biometers, we applied and validated a biometry-based technique for estimating AST using optical coherence tomography (OCT) landmarks.

Methods

The AST was determined across four meridians in 62 participants (aged 20-37 years) with a swept-source OCT and a noncontact optical biometer at a mean ± SD distance of 3.13 ± 0.88 mm from the limbus. The biometer's graticule was focused and aligned with the anterior scleral reflex, which led to the generation of four prominent A-scan peaks: P1 (anterior bulbar conjunctiva), P2 (anterior episclera), P3 (anterior margin of anterior sclera), and P4 (posterior margin of anterior sclera), which were analyzed and compared with the corresponding OCT landmarks to determine tissue thickness.

Results

The AST measurements between biometer and OCT correlated for all meridians (r ≥ 0.70, overall r = 0.82; coefficient of variation [CV], 9%-12%; P < 0.01). The mean difference ± SD between two instruments for overall AST measures was 3 ± 2.8 µm (range, -18 to +16 µm; lower limits of agreement, -89 to +83 µm; P = 0.23) across all meridians. The mean ± SE AST with both instruments was found to be thickest at the inferior (562 ± 7 µm and 578 ± 7 µm) and thinnest at the superior (451 ± 7 µm and 433 ± 6 µm) meridian. The biometer demonstrated good intrasession (CV, 8.4%-9.6%) and intersession (CV, 7.9%-13.3%) repeatability for AST measurements across all meridians.

Conclusions

The noncontact optical biometer, which is typically used to determine axial length, is capable of accurately estimating AST based on OCT landmarks.

Translational Relevance

The high-resolution optical biometers can demonstrate wider application in the field of myopia research and practice to determine AST.

Scleral changes in systemic lupus erythematosus patients using swept source optical coherence tomography

Purpose

This study aims to examine scleral thickness in patients with systemic lupus erythematosus (SLE) without clinically evident scleritis and episcleritis, utilizing swept-source optical coherence tomography (SS-OCT).

Methods

This cross-sectional single center study compared scleral thickness (Nasal scleral thickness 1mm, 2mm, 3mm, 6mm from scleral spur; Temporal scleral thickness 1mm, 2mm, 3mm, 6mm from scleral spur) in 73 SLE patients without clinically evident scleritis and episcleritis and 48 healthy volunteers with SS-OCT. Further, we investigated the correlation between scleral thickness in SLE patients and various parameters including laboratory markers, disease duration, disease activity, and organ involvement.

Results

Across all measured sites (nasal scleral thickness at distances of 1mm, 2mm, 3mm, and 6mm from the scleral spur, and temporal scleral thickness at the same distances), the scleral thickness in the SLE group was significantly greater than that in the control group (all p-values <0.001). SLE patients with a disease duration of 5 years or less exhibited a higher scleral thickness compared to those with a more prolonged disease duration. Patients with a higher erythrocyte sedimentation rate (ESR) had a thinner temporal scleral thickness. However, no significant associations were identified between scleral thickness and disease activity, organ involvement, or other laboratory markers.

Conclusion

Scleral thickness measured by SS-OCT was higher in SLE patients than healthy controls. Changes in scleral thickness in SLE patients are related to disease duration and ESR. SS-OCT can detect asymptomatic structural changes in SLE patients and may be a useful tool in the evaluation of early scleral abnormality.

Role of anterior segment optical coherence tomography in scleral diseases: A review

BACKGROUND

Scleritis and episcleritis are an overlapping spectrum of diseases and accurate diagnosis is of utmost importance as the treatment and prognosis are vastly different. Predominantly a clinical diagnosis, the challenge lies in those cases with equivocal clinical features. Furthermore, clinical grading of scleritis is subjective and hence is neither very reliable nor reproducible. Existing modalities such as slit lamp examination and clinical photographs in scleritis describe macroanatomy but do not provide details on the microanatomy of the sclera. A recent adjusted algorithm for anterior segment optical coherence tomography (AS-OCT) imaging has improved the ability of this device to aid in the diagnosis of all the major forms of scleritis.

PURPOSE

To highlight the role of AS-OCT in delineating various anatomical forms of episcleritis and scleritis and explore this tool in monitoring disease course and response to therapy.

METHODS

A comprehensive literature search was carried out in various medical databases using keywords AS-OCT and scleritis; AS-OCT and episcleritis; anterior segment imaging in scleritis; scleritis and episcleritis; Recent advances in anterior segment imaging. Original articles and novel reports describing the potential role of AS-OCT in the diagnosis and management of scleritis and episcleritis were included.

RESULTS

After a thorough assessment, it was clear that published literature lacks guidelines for uniform interpretation and also for classification and follow-up in scleritis. We describe a uniform protocol for AS-OCT image acquisition, interpretation of images and list the advantages and limitations.

CONCLUSIONS

AS-OCT can be used to localize the level of scleral inflammation thus helping in the diagnosis of scleral inflammatory disease. It can be a valuable tool in studying progression.

Monitoring therapy in anterior necrotizing scleritis with inflammation with anterior segment optical coherence tomography

INTRODUCTION

Early diagnosis and initiation of immunosuppression can prevent the necessity of surgical intervention in necrotizing scleritis with inflammation and lowers the risk of perforation and loss of vision. However, clinical signs for early diagnosis and methods for monitoring response to immunosuppressive therapy are missing.

METHODS

Here, we present a case of necrotizing scleritis with inflammation where avascular plaques precede scleral defects. We use slit lamp imaging and anterior segment optical coherence tomography to evaluate evolution lesions depth and impact on scleral structure.

RESULTS

The patient presented 5 months after detection of avascular plaques with a new scleral ulcer of the left eye. After 3-day-administration of i.v. corticosteroids anterior segment optical coherence tomography showed progressive scleral thickening. The patient was therefore spared surgical intervention and discharged resulting in complete remission under decreasing doses of oral corticosteroids.

CONCLUSIONS

Avascular plaques can precede necrotizing scleritis with inflammation by several months and may therefore qualify as early clinical signs. Anterior segment optical coherence tomography enables objective evaluation of scleral structure for making rational decisions about surgical intervention.

Optical coherence tomography versus ophthalmic examination findings in the management of anterior scleritis: A prospective study

PURPOSE

The goal of this work was to analyze optical coherence tomography (OCT) findings compared to ophthalmic examination results in the management of anterior scleritis.

METHODS

We carried out a prospective study including patients presenting with anterior scleritis who underwent complete clinical examinations and OCT at baseline and at the final follow-up visit.

RESULTS

The mean age was 46years. The superior and temporal quadrants were clinically the most involved regions and showed the greatest thickness on the OCT images. Nodules were observed clinically in 6 patients, while OCT revealed them in 9 cases. OCT revealed 3 cases of sub-clinical necrosis. Separation of fibers, scleral edema, dilated vessels, fluid pockets and increased scleral thickness were the most common signs of the disease. Mean total scleral thickness and mean scleral-episcleral complex thickness were significantly improved after treatment (P=0.001 and P=0.00; respectively). Post-streptococcal syndrome (PSS) was diagnosed in 3 cases of non-necrotizing anterior scleritis. Necrotizing forms were low-grade and were associated with systemic diseases in 2 out of 3 patients. OCT signs persisted for a substantial time after resolution of clinical signs.

CONCLUSION

OCT helped to distinguish necrosis and scleral nodules in subclinical cases. Non-necrotizing forms of scleritis supported the diagnosis of PSS, while necrotizing forms suggested systemic diseases. Complete resolution of a scleral inflammation could be followed more objectively with OCT than by clinical examination.

The relationship of ocular parameters with clinical parameters and disease-related quality of life in patients with systemic sclerosis: A cross-sectional study

OBJECTIVE

To evaluate choroidal thickness (CT), corneal parameters, and scleral thickness (ST) in patients with systemic sclerosis (SSc) and to determine their relationship with disease-related quality of life (QoL).

METHODS

The study included 38 patients with SSc and 40 healthy controls. A detailed ocular examination was performed on all participants. Corneal parameters such as K1, K2, Km, corneal volume (CV), central corneal thickness (CCT), and ST at a distance of 1000, 2000, and 3000 μm from the scleral spur were measured. CT was measured at five points, including the subfoveal area and the temporal and nasal points at radii of 750.0 and 1500.0 μm. The scleroderma health assessment questionnaire (SHAQ) was administered to SSc patients to investigate the disease-related QoL.

RESULTS

Individuals with SSc had thicker ST at all distances from the scleral spur (P=0.008, P=0.001, P=0.002, respectively). All corneal parameters were significantly lower in the SSc group than in the control group (P < 0.05). Moreover, SSc patients had significantly lower median CT at N750.0, N1500.0, T750.0, and T1500.0 points and thinner subfoveal CT than healthy controls (P < 0.05). There was a weak-moderate negative correlation between ST and the components of the SHAQ scale and SHAQ-global.

CONCLUSION

Despite not having ocular involvement, SSc patients had thicker ST but thinner CT and corneal parameters than healthy controls. This may indicate subclinical inflammation in patients with SSc. Only ST was affected by organ involvement and QoL among the ocular parameters.

Optical Coherence Tomography Findings in Nodular Anterior Scleritis due to Post-Streptococcal Syndrome

Purpose

To report a case of nodular anterior scleritis due to poststreptococcal syndrome using optical coherence tomography imaging.

Case Report

A 41-year-old woman with a history of acute rheumatic fever presented with a nodular anterior scleritis. Common causes were excluded. Optical coherence tomography of sclera showed enlarged vessels, inflammatory infiltrates, separated fibers, and a serous detachment. Laboratory investigations showed an elevated erythrocyte sedimentation rate, raised anti-streptolysin O titer, and the presence of group A streptococcus in the throat. The scleritis rapidly improved with penicillin treatment.

Conclusion

Poststreptococcal syndrome should be considered in the etiology of non-necrotizing anterior scleritis.

Recent Advances in Diagnosis and Treatment of Infectious Uveitis Prevalent in Asia-Pacific Region

ABSTRACT

The role of infections in intraocular inflammation is being increasingly recognized across the world. The Asia-Pacific region, being the single largest and most populous geographical entity on the planet, is home to a wide variety of such infections. Not surprisingly, there has been an explosion in the literature on infectious uveitis emerging from Asia-Pacific countries. In this review, we have covered recent advances in the diagnosis, treatment, and pathogenesis of common forms of infectious uveitis from the Asia-Pacific region. Much of the literature is focussed on the diagnosis of these infections by clinical criteria and laboratory investigations. There has also been an increased emphasis on the application of newer modes of ocular imaging and understanding pathomechanisms of ocular inflammation in these infections. Together this research has significantly improved our understanding of the diagnosis and management of infectious uveitis.

Measurements of scleral thickness and corneal optic densitometry in patients with systemic lupus erythematosus

BACKGROUND

This study aimed to evaluate the scleral thickness and corneal parameters of patients with systemic lupus erythematosus (SLE).

METHODS

Forty-seven eyes of 47 SLE patients and 44 eyes of healthy controls were included in this cross-sectional study. Anterior segment optical coherence tomography (AS-OCT) was used to measure the corneal and scleral thickness. Scleral thickness (ST) was measured based upon the segmentation at 1000 to 5000 μm from the scleral spur. Pentacam HR was used to measure corneal parameters.

RESULTS

There was no statistically significant difference between SLE group and control group according to age and sex (P > .05). The ST measurements at all distances from scleral spur were found to be thicker in patients with SLE (P < .05). Central corneal thickness (CCT), cornea volume (CV), corneal densitometry (CD), and peripheral corneal thickness (PCT) measurements were similar between the groups (P > .05).

CONCLUSION

ST was thicker in SLE patients compared with healthy controls. AS-OCT seems helpful in selecting optimal sites for pharmaceutical or surgical intervention in SLE patients, since it shows thickness variations in anterior sclera.

Current insights in the pathogenesis of scleritis

Scleritis is a sight-threatening inflammation characterized by severe pain and redness of the eye. It can cause blindness by severe complications like scleral and corneal necrosis, keratitis, and uveitis. The pathogenesis of scleritis is largely unknown due to a combination of the rarity of the disease, the little available human tissue-based research material, and the lack of animal models. The immune system is assumed to play a crucial role in the pathogenesis of scleritis. Multiple clues indicate probable antigenic stimuli in scleritis, and the involvement of matrix metalloproteinases in the destruction of scleral tissue. In this article we review the current insights into the pathogenesis of scleritis, and we suggest new hypotheses by implementing knowledge of systemic autoimmune disease pathogenesis. Understanding the pathogenesis of scleritis is crucial to improve the clinical management, as well as to find novel treatment modalities.

Anterior Segment Optical Coherence Tomography Angiography and Optical Coherence Tomography in the Evaluation of Episcleritis and Scleritis

Purpose: To evaluate the feasibility of using anterior segment optical coherence tomography (AS-OCT) and AS-OCT angiography (AS-OCTA) in assessing patients with episcleritis and scleritis.Methods: Degree of vascularity [vessel density index (VDI)], measured with AS-OCTA, and sclera thickness [conjunctiva epithelium (CE), conjunctiva/episclera complex (CEC), and episclera/sclera complex (ESC)], measured with AS-OCT were compared.Results: A total of 37 eyes (13 episcleritis, 11 scleritis, 13 controls) were analyzed. VDI was lowest for controls for the various tissue depths (p < .001). Episcleritis versus scleritis revealed a significant difference in VDI at ESC (38.1 ± 11.4% vs 46.4 ± 6.4%; p = .03). Mean sclera thickness was lower in controls for CE (p < .001), CEC (p < .001) but not for ESC (p = .54).Conclusions: The degree of vascularity and tissue thickness were different between episcleritis, scleritis and controls. AS-OCTA and AS-OCT may potentially be useful in evaluating patients with scleral inflammation.

Anterior segment optical coherence tomography and its clinical applications

Anterior segment optical coherence tomography (AS-OCT) has become one of the cornerstones of non-contact imaging modalities for assessing such structures as the cornea, anterior chamber angle, aqueous outflow pathway, sclera, and ocular surface structures. As such, it has a broad range of clinical applications, which have been independently reported in the literature. This paper aims to present a review of extant literature on the utility of AS-OCT and its efficacy in clinical applications, and to evaluate the quality of available evidence. The following databases were searched from inception to 24 June 2018: Medline via Ovid, Cochrane Central Register of Controlled Trials, PubMed, World Health Organization International Clinical Trials Registry Platform, EMBASE, and CINAHL. Bibliographies of identified papers were hand searched. Inclusion criteria: articles describing or assessing the use of OCT for visualising the AS. The authors excluded studies without an identified primary outcome variable. One author independently selected studies, extracted data, and assessed for risk of bias using PRISMA guidelines. This review included 82 studies, of which there were 11 cohort studies, 37 case series, 10 case studies, 21 comparative observational studies, and three non-systematic review articles. Primary outcome variables included anterior chamber angle, angle opening distance, angle recess area, trabecular iris angle, trabecula-iris space area, corneal thickness, tear meniscus height, tear meniscus area, tear meniscus volume, and the morphology of AS structures, including the ocular surface, blebs, flaps, and graft sites. This review attempts to encompass the breadth and depth of evidence for AS-OCT in the arena of diagnostics, therapeutics, and prognostics. At the same time, it brings to light the dearth of high-level evidence on this topic, suggesting the important role of randomised controlled trials and meta-analyses for the future validation of this technology.

[Diagnosis and treatment of episcleritis and scleritis]

Episcleritis is a benign and self-limiting disease, often with a recurrent course, manifesting mainly in young adults. In less than a third of patients, an associated systemic disease can be found. In contrast, scleritis is observed mainly in patients between the 4th and 6th decade of life, may lead to severe ocular complications, and is often associated with a systemic rheumatological disease. Diffuse, nodular, and necrotizing forms of scleritis can be differentiated. Necrotizing and posterior scleritis have a higher risk of complications and worse visual outcome. In most cases, medical history and slit lamp examination allow differentiation of episcleritis and scleritis. Whereas episcleritis is treated mainly symptomatically with artificial tears, topical corticosteroids, and potentially with systemic nonsteroidal anti-inflammatory drugs, scleritis requires early and aggressive anti-inflammatory treatment in a stepwise approach.

An OCT Study of Anterior Nodular Episcleritis and Scleritis

Anterior scleritis and episcleritis are a well-known presentation in tuberculosis. The case of a female patient with presumed tuberculous anterior scleritis and episcleritis is discussed in this article. Anterior segment OCT was efficient in diagnosis and evaluation of the therapeutic outcome. Antituberculosis chemotherapy was sufficient to achieve clinical remission.

Anterior eye tissue morphology: Scleral and conjunctival thickness in children and young adults

The sclera and conjunctiva form part of the eye's tough, protective outer coat, and play important roles in the eye's mechanical protection and immune defence, as well as in determining the size and shape of the eye globe. Advances in ocular imaging technology now allow these tissues in the anterior eye to be imaged non-invasively and with high resolution, however there is a paucity of data examining the dimensions of these tissues in paediatric populations. In this study, we have used optical coherence tomography (OCT) imaging to examine the normal in vivo thickness profile of the anterior sclera and overlying conjunctiva in 111 healthy young participants, including a large proportion of paediatric subjects. We demonstrate that the thickness of the anterior sclera varies significantly with measurement location and meridian. Tissue thickness also varied significantly with age, with younger subjects exhibiting significantly thinner scleras and significantly greater conjunctival thickness. Males were also found to exhibit significantly greater scleral thickness. Refractive error however was not significantly associated with either scleral or conjunctival thickness in this population. These findings provide new data describing the normative dimensions of anterior eye tissues in children and the factors that can influence these dimensions in young populations.

High-resolution ultrasound biomicroscopy as an adjunctive diagnostic tool for anterior scleral inflammatory disease

PURPOSE

To study high-resolution ultrasound biomicroscopy (UBM) findings in anterior scleral inflammatory disease and evaluate the efficacy of high-resolution UBM as an adjunctive diagnostic tool.

METHODS

A cross-sectional study. The medical records of 30 patients (33 eyes) with episcleritis or anterior scleritis were reviewed for clinical features and high-resolution UBM findings. Ultrasound biomicroscopy (UBM) examination was performed using 50 MHz Aviso S (Quantel Medical, Clermont-Ferrand, France).

RESULTS

Seventeen eyes had episcleritis [nodular (12), simple (five)], and 16 eyes had anterior scleritis [nodular (14), diffuse (two)] as classified by UBM. The use of high-resolution UBM allowed high-resolution imaging of the sclera and episclera and showed characteristic patterns of episcleritis and anterior scleritis. The clinical classification matched UBM findings in 25 (76%) eyes. In the other eight eyes (24%), UBM analysis led to a change in the final classification: four eyes with suspected episcleritis were classified with scleritis, and four eyes with suspected scleritis were classified with episcleritis. Eleven patients (36.7%) had an associated systemic disease.

CONCLUSION

High-resolution UBM enabled visualization of distinct imaging findings of episcleritis and anterior scleritis, indicating its usefulness in the classification of challenging cases of anterior scleral inflammatory disease.

Particle size and morphological characterization of cosmetic emulsified systems by Optical Coherence Tomography (OCT)

ABSTRACT The physicochemical attributes of emulsified systems are influenced by the characteristics of their internal phase droplets (concentration, size and morphology), which can be modified not only by the formulation components, but also by the analytical methodology employed. Thus, the aim of this work involved the physicochemical characterization of cosmetic emulsions obtained from different surfactants, as well as the introduction of the optical coherence tomography (OCT) as the analytical technique employed for the morphological characterization and particle size determination of the formulations. Three emulsions were prepared, differing at the type and concentration of the surfactant used, and their droplet sizes were evaluated through optical microscopy, laser diffraction and OCT. The microscopic analysis and the laser diffraction techniques provided an average particle size minor than 6.0 µm, not detected by the OCT technique, which could identify only bigger particles of the emulsified systems' internal phase. The results testify that OCT was suitable for the morphological characterization of cosmetic emulsions; however, the technique needs to be improved to ensure a better sensitivity in the analysis of smaller particles.

Diurnal variation of anterior scleral and conjunctival thickness

PURPOSE

To examine whether anterior scleral and conjunctival thickness undergoes significant diurnal variation over a 24-h period.

METHODS

Nineteen healthy young adults (mean age 22 ± 2 years) with minimal refractive error (mean spherical equivalent refraction -0.08 ± 0.39 D), had measures of anterior scleral and conjunctival thickness collected using anterior segment optical coherence tomography (AS-OCT) at seven measurement sessions over a 24-h period. The thickness of the temporal anterior sclera and conjunctiva were determined at six locations (each separated by 0.5 mm) at varying distances from the scleral spur (SS) for each subject at each measurement session.

RESULTS

Both the anterior sclera and conjunctiva were found to undergo significant diurnal variations in thickness over a 24-h period (both p < 0.01). The sclera and conjunctiva exhibited a similar pattern of diurnal change, with a small magnitude thinning observed close to midday, and a larger magnitude thickening observed in the early morning immediately after waking. The amplitude of diurnal thickness change was larger in the conjunctiva (mean amplitude 69 ± 29 μm) compared to the sclera (21 ± 8 μm). The conjunctiva exhibited its smallest magnitude of change at the SS location (mean amplitude 56 ± 17 μm) whereas the sclera exhibited its largest magnitude of change at this location (52 ± 21 μm).

CONCLUSIONS

This study provides the first evidence of diurnal variations occurring in the thickness of the anterior sclera and conjunctiva. Studies requiring precise measures of these anatomical layers should therefore take time of day into consideration. The majority of the observed changes occurred in the early morning immediately after waking and were of larger magnitude in the conjunctiva compared to the sclera. Thickness changes at other times of the day were of smaller magnitude and generally not statistically significant.