Ultrasound biomicroscopy in scleritis

Morphometric Assessment of Sclera and Ciliary Body in Patients with Noninfectious Anterior Scleritis: A Quantitative Study Using Ultrasound Biomicroscopy

BACKGROUND

At present, the severity and grade of anterior scleritis are judged mainly based on the area and location of involvement, whether there is necrosis, etc. Quantitative measurement of sclera and surrounding tissues will help to accurately assess the severity of scleritis and provide quantitative indicators for the choice of treatment.

METHODS

We retrospectively analyzed the thickness of sclera and ciliary bodies detected by ultrasound biological microscopy (UBM) in noninfectious anterior scleritis patients who subsequently were treated with topical or systemic treatment, and visited our hospital from March 2014 to March 2021. Age- and sex-matched normal individuals were used as controls.

RESULTS

A total of 185 patients (50 males and 135 females) with noninfectious anterior scleritis and 84 (31 males and 53 females) controls were included. In patients with noninfectious scleritis, the thickness of sclera and the ciliary body were significantly greater than those in the control group (p < 0.05). Before treatment, the thickness of sclera and the ciliary body in systemic treatment group was significantly higher than that in topical treatment group (p < 0.05). After treatment, both thicknesses of sclera and the ciliary body decreased significantly (p < 0.05). The ratio of ciliary body thickness from the site of inflammation to the normal position was significantly higher in the systemic treatment group than in the topical treatment group.

CONCLUSIONS

UBM quantitatively shows a decrease in AST/CBT in patients with anterior scleritis after treatment. The ratio of ciliary body thickness at the site of information to that at the normal position may be a reference for the choice of treatment.

Assessment of conjunctival, episcleral and scleral thickness in healthy individuals using anterior segment optical coherence tomography

PURPOSE

To determine the thickness of the conjunctiva, episclera and sclera in healthy individuals using anterior segment optical coherence tomography (AS-OCT).

METHODS

We prospectively included 107 healthy individuals of different age groups (18-39 years, 40-54 years, 55-69 years and ≥70 years). For each eye, AS-OCT scans of four quadrants (temporal, nasal, superior and inferior) were acquired. The thickness of the conjunctiva, episclera and sclera was measured for each scan. In addition, the axial length of both eyes was measured, and general characteristics, including smoking, allergies and contact lens use, were collected.

RESULTS

The mean conjunctival thickness was significantly different between the nasal and superior quadrants (87 ± 30 μm vs. 77 ± 16 μm; p < 0.001), as well as the superior and inferior quadrants (77 ± 16 μm vs. 86 ± 19 μm; p = 0.001). The mean episcleral thickness was larger in the superior (174 ± 54 μm) and inferior (141 ± 43 μm) quadrants, compared to the nasal (83 ± 38 μm) and temporal quadrants (90 ± 44 μm). The mean scleral thickness of the inferior quadrant was the largest (596 ± 64 μm), followed by the nasal (567 ± 76 μm), temporal (516 ± 67 μm) and superior (467 ± 52 μm) quadrants (all p < 0.001). The averaged scleral thickness increased 0.96 μm per age year (0.41-1.47 μm, p < 0.001).

CONCLUSIONS

This study provides an assessment of the thickness of scleral and adjacent superficial layers in healthy individuals determined on AS-OCT, which could enable future research into the use of AS-OCT in diseases affecting the anterior eye wall.

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.

[Diagnostic and Therapeutic Management of Episcleritis and Scleritis]

While episcleritis is a benign disease only affecting the episclera, scleritis is an ocular inflammation with typically severe pain and not rarely affecting adjacent tissue.Scleritis is classified into anterior and posterior forms. Anterior scleritis is further subdivided into diffuse, nodular, necrotizing with inflammation, and necrotizing scleritis without inflammation (scleromalacia perforans). A systemic disease such as rheumatoid arthritis or granulomatosis with polyangiitis is associated with up to 50% of all patients with scleritis or episcleritis, consequently a systemic work-up with blood sampling and imaging as well as collaboration with internists are necessary.Differentiating these two entities is of high importance for planning the treatment: episcleritis has a self-limited course, whereas treatment of scleritis is obligatory to protect patients from irreversible visual loss, organ damage, and furthermore reduce the risk of mortality.Treatment depending of subtype and associated systemic disease may involve non-steroidal anti-inflammatory drugs, corticosteroids, and disease-modifying anti-rheumatic drugs.

Diagnostisches und therapeutisches Management der Episkleritis und Skleritis

Das schmerzhafte „rote Auge“ ist wohl das auffälligste Zeichen einer Augenerkrankung, hinter der milde, aber auch schwere Verläufe stecken können. Die Episkleritis und Skleritis sind hierbei wichtige Differenzialdiagnosen. Die rechtzeitige Diagnose ist nicht nur wichtig für die notwendige Therapie, sondern kann vor einer irreversiblen Visusminderung, einem Augenverlust sowie Organschäden schützen und ggf. sogar das Mortalitätsrisiko senken.

Management of scleral melt

Scleral melting, while rare, can lead to significant ocular morbidity. Several possible risk factors for scleral melt have been identified, such as infection, autoimmune disease, trauma, and post-surgical state, and these may act in combination with each other. Treatment should be tailored according to the etiology and severity of the scleral melt. Medical management may be indicated, especially in cases of autoimmune-related melt; however, surgical procedures are often necessary due to compromised ocular integrity and limited penetration of medications into the avascular sclera. An understanding of the surgical options available and their operative outcomes is particularly important when choosing the appropriate treatment protocol for each patient.

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.

[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.

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.

Ultrasound Biomicroscopic Evaluation of Uveal Effusion in Acute Primary Angle Closure

PURPOSE

The aim of this study was to determine the prevalence of uveal effusion in acute primary angle closure (APAC), chronic primary angle-closure glaucoma (PACG), and primary open-angle glaucoma (POAG).

METHODS

A total of 152 consecutive patients (287 eyes) with APAC, PACG, and POAG were enrolled in this prospective and observational case series study. Intraocular pressure-lowering medications were used and ultrasound biomicroscopy examination was undertaken to determine the presence of uveal effusion and measure anterior chamber parameters.

RESULTS

Overall, uveal effusion was evident in 40 of 194 affected eyes (20.6%) and no uveal effusion was seen in their fellow eyes. The prevalence of uveal effusion in APAC, chronic PACG, and POAG was 29.3%, 10.9%, and 3.1%, respectively (χ=226.63, P<0.001). APAC eyes had the highest prevalence of effusion and no effusion in their fellow eyes. In 40 eyes with uveal effusion, grade 1 effusion was seen in 17 eyes (42.5%), grade 2 in 15 eyes (37.5%), and grade 3 in 8 eyes (20%). In APAC eyes, the difference in the mean anterior chamber depth (ACD) among effusion grades 3, 2, and 1 was significant (F=5.425, P=0.017), and the eyes with grade 3 effusion had shallower ACD compared with grade 1 (P=0.031), but the difference was not significant compared with grade 2 (P=0.368).

CONCLUSIONS

The eyes with APAC are associated with a higher prevalence of uveal effusion compared with PACG and POAG and probably as a result of rapid reduction in intraocular pressure with aggressive hypotensive therapy and inflammatory response to the process of acute attack.

Very-high-frequency ultrasound corneal imaging as a new tool for early diagnosis of ocular surface toxicity in rabbits treated with a preserved glaucoma drug

AIM

To evaluate very-high-frequency (VHF) ultrasound imaging as a new method to detect and quantify early corneal epithelium changes induced by chronic exposure to a benzalkonium-chloride-containing antiglaucoma drug.

METHODS

Timolol preserved with 0.01% benzalkonium chloride solution was applied b.i.d. in 1 eye of 10 rabbits for 56 days. Unpreserved timolol solution was used as control. Ocular surface changes were assessed weekly combining clinical examinations, in vivo 60-MHz ultrasound imaging and ex vivo histological analysis.

RESULTS

VHF ultrasound imaging allowed quantitative measurement of corneal epithelium thickness and qualitative imaging of toxic epithelial damage. It revealed significantly decreased epithelial thickness in vivo as early as the 21st day of treatment (40.75 +/- 1.72 microm at D0 vs. 39 +/- 2 at D21, vs. 31.9 +/- 2.98 at D56; p = 0.017 and p = 0.005, respectively). The first clinical changes appeared from the 42nd day of treatment (conjunctival redness, conjunctival staining and corneal staining; D56 compared to D0: p = 0.005, 0.01 and 0.004, respectively) and then correlated with VHF ultrasound data. Epithelial thickness measured with VHF ultrasound was correlated with histological epithelial pachymetry (p < 0.001) and with the corneal damage score assessed with scanning electron microscopy (p = 0.038).

CONCLUSION

VHF ultrasound imaging provided an early in vivo diagnosis of corneal epithelium pathology induced by chronic exposure to a preserved glaucoma drug, before the first clinical evidence of ocular toxicity. It could be a new reproducible method to detect the toxicity of glaucoma medication so that therapy can then be adapted.

Uveal effusion in primary angle-closure glaucoma

PURPOSE

To determine the prevalence of uveal effusion in acute and chronic primary angle-closure glaucoma (PACG) or primary angle closure (PAC) and to compare it with the prevalence in eyes with open-angle glaucoma (OAG) or ocular hypertension.

DESIGN

Prospective consecutive case series.

PARTICIPANTS

Five hundred one eyes of 351 consecutive patients with PAC and 156 eyes of 116 randomly selected primary OAG or ocular hypertension patients. The PAC group included 40 eyes of 35 patients with acute PACG and 30 unaffected fellow eyes, 39 eyes and 35 fellow eyes with a history of acute PACG, and 357 eyes with chronic PAC.

METHODS

Ultrasound biomicroscopic examination was performed to diagnose uveal effusion and to measure anterior chamber depth (ACD).

MAIN OUTCOME MEASURES

Presence of uveal effusion and ACD.

RESULTS

Uveal effusion was demonstrated in 23 eyes (58%) with acute PACG and 7 fellow eys (23%) (chi2 = 8.17, P = 0.0043). Among eyes with chronic PAC, uveal effusion was present in 69 [corrected](14%[corrected]), a higher prevalence than was found in open-angle patients (2 eyes [1.3%]) (chi2 = 19.3, P<0.001). In the chronic PAC group, the ACD of phakic eyes with uveal effusion (1.92+/-0.42 mm) was significantly shallower than that of phakic eyes without effusion (2.06+/-0.32 mm) (P = 0.019).

CONCLUSIONS

Uveal effusion diagnosed by ultrasound biomicroscopy is a special feature in PAC, and is prevalent in acute PACG. Uveal effusion in phakic eyes with PAC is associated with shallowing of ACD.

Anterior segment indocyanine green angiography in anterior scleritis and episcleritis

OBJECTIVE

To evaluate the pattern of anterior segment indocyanine green (ICG) angiography in episcleritis and scleritis.

DESIGN

Prospective comparative (paired-eye) observational case series.

PARTICIPANTS

Twenty subjects presenting clinical diseases compatible with episcleritis or scleritis.

METHODS

Anterior segment ICG angiography was performed according to a standard protocol in subjects presenting either episcleritis or scleritis. Photographs of the anterior segment were taken in the early phase (up to 3 minutes after dye injection), intermediate phase (10-12 minutes) and late phase (30-45 minutes). The inflamed zones were compared with the same regions of the controlateral eye. The amount of protein ICG exudation was scored by a masked observer as follows: zero for no exudation, one for slight exudation, two for moderate exudation, and three for severe exudation.

MAIN OUTCOME MEASURES

Evaluation of dye leakage, which reflects protein exudation, with anterior segment ICG angiography in episcleritis and scleritis.

RESULTS

Twenty subjects with a mean age of 43 +/- 15 years (7 male, 13 female) were enrolled in the study. Thirteen subjects had anterior scleritis (7 nodular, 5 diffuse, and 1 scleromalacia perforans), and 7 subjects had episcleritis. Only 1 out of 7 subjects with episcleritis showed a slight ICG leakage (a score of one), whereas all subjects with scleritis had ICG leakage scores of one or more (P = 0.0005, Fisher exact test).

CONCLUSIONS

ICG angiography of the anterior segment of the eye is a good clinical test to differentiate episcleritis from scleritis.

Value of high-frequency ultrasound biomicroscopy in uveitis

PURPOSE

To determine the use of high-frequency ultrasound biomicroscopy (UBM) in the assessment of inflammatory lesions of the iris, ciliary body, pars plana and peripheral vitreous, and in particular to determine the proportion of cases for which UBM contributed significant additional, hitherto inaccessible, information.

METHODS

Charts of patients seen in the uveitis clinic at University Eye Hospital from November 1994 to September 1999 for whom a UBM investigation had been performed were analysed. UBM was performed in a standard manner, using a Humphrey UBM 840 system. The clinical relevance of the UBM findings was determined for the whole series and for the following six subgroups of patients arbitrarily established according to the type and location of pathology: hypotony, pseudophakic uveitis, iris and ciliary body pathology excluding hypotony, pars plana pathology, scleritis and Toxocara uveitis. Findings were classified as positive when they confirmed a suspected diagnosis of lesional process or when they gave essential information. Findings were classified as essential when they led to the diagnosis or when they modified therapeutic intervention.

RESULTS

During the study period 111 eyes of 77 patients were included. UBM findings contributed essential information that allowed a diagnosis to be reached or that influenced treatment in 43% of cases. It yielded positive findings in 91% of cases, enabling assessment of morphological changes in the iris, ciliary body, and retroiridal and peripheral vitreous induced by intraocular inflammatory or pseudo-inflammatory disorders. Specific UBM signs, present in all patients, were identified in Toxocara uveitis. The groups of patients that benefited most from UBM examination were those with hypotony (83% essential findings) and opaque media (100% essential findings).

CONCLUSION

For uveitis patients with an inflammatory process situated in the iris/ciliary body/pars plana/retroiridal vitreous areas, UBM was of great clinical value and improved the management in a significant manner.

Advances in ultrasound biomicroscopy

The visualisation of living tissues at microscopic resolution is attracting attention in several fields. In medicine, the goals are to image healthy and diseased tissue with the aim of providing information previously only available from biopsy samples. In basic biology, the goal may be to image biological models of human disease or to conduct longitudinal studies of small-animal development. High-frequency ultrasonic imaging (ultrasound biomicroscopy) offers unique advantages for these applications. In this paper, the development of ultrasound biomicroscopy is reviewed. Aspects of transducer development, systems design and tissue properties are presented to provide a foundation for medical and biological applications. The majority of applications appear to be developing in the 40-60-MHz frequency range, where resolution on the order of 50 microm can be achieved. Doppler processing in this frequency range is beginning to emerge and some examples of current achievements will be highlighted. The current state of the art is reviewed for medical applications in ophthalmology, intravascular ultrasound, dermatology, and cartilage imaging. Ultrasound biomicroscopic studies of mouse embryonic development and tumour biology are presented. Speculation on the continuing evolution of ultrasound biomicroscopy will be discussed.