Infectious Scleritis: Pathophysiology, Diagnosis, and Management

Infectious scleritis: a review of etiologies, clinical features, and management strategies

Infectious scleritis is a severe and potentially vision-threatening inflammation of the sclera caused by microbial invasion. Unlike autoimmune scleritis, infectious scleritis is less common with a prevalence of 5%-10% of all cases of scleritis. The initial clinical presentation may often resemble autoimmune scleritis, thus resulting in a delayed diagnosis and poorer outcomes. A high level of suspicion is required in such cases and risk factors such as with a history of trauma or surgery and worsening or refractory to immunosuppressive medications as these may well be infectious. While in established cases, the classical clinical features enable us to diagnose as infectious etiology without much difficulty, the management remains a challenge. Majority of these cases require an aggressive approach with a combination of antimicrobial therapy and surgical treatment. Poor prognostic factors include delayed diagnosis, fungal etiology, and the presence of keratitis or endophthalmitis. In this review, the authors have summarized the prevalence, clinical and microbiological profile, and management strategies of infectious scleritis and their outcomes.

Necrotizing Scleritis: A Review

Necrotizing scleritis is the most destructive and vision-threatening form of scleritis. Necrotizing scleritis can occur in systemic autoimmune disorders and systemic vasculitis, as well as following microbial infection. Rheumatoid arthritis and granulomatosis with polyangiitis remain the commonest identifiable systemic diseases associated with necrotising scleritis. Pseudomonas species is the most common organism causing infectious necrotizing scleritis, with surgery the most common risk factor. Necrotizing scleritis has the highest rates of complications and is more prone to secondary glaucoma and cataract than other phenotypes of scleritis. The differentiation between non-infectious and infectious necrotizing scleritis is not always easy but is critical in the management of necrotizing scleritis. Non-infectious necrotizing scleritis requires aggressive treatment with combination immunosuppressive therapy. Infectious scleritis is often recalcitrant and difficult to control, requiring long-term antimicrobial therapy and surgical debridement with drainage and patch grafting due to deep-seated infection and the avascularity of the sclera.

Determinants of Clinical Outcomes After Infectious Scleritis

PURPOSE

The aims of this study were to describe the clinical course of microbial infectious scleritis and identify factors associated with poor visual outcomes.

METHODS

Data from 26 eyes of 26 patients with culture-proven bacterial or fungal scleritis presenting at a single tertiary center from January 1, 2007, to July 1, 2021, were reviewed. Thirty-six variables were analyzed for associations with poor vision [best-corrected visual acuity (BCVA) <20/200] or loss of vision (no light perception vision or requirement for enucleation or evisceration) at final visit.

RESULTS

The mean age at initial presentation was 67.1 ± 14.0 (range: 34-92) years with a mean follow-up of 2.1 ± 2.2 (0.05-8.45) years. The mean presenting logarithm of minimal angle of resolution (logMAR) BCVA was 1.3 ± 1.0 (∼20/400) and mean final logMAR BCVA was 1.6 ± 1.2 (∼20/800). Fourteen eyes (53.8%) exhibited poor vision and 7 (26.9%) had loss of vision at final follow-up. History of necrotizing scleritis and poor presenting vision were associated with poor final vision (OR = 19.1; P = 0.017 and OR = 7.5; P = 0.047, respectively), whereas fungal scleritis was associated with loss of vision (odds ratio [OR] = 30.3, P = 0.013). Subconjunctival antimicrobial treatment was inversely associated with loss of vision (OR = 0.06, P = 0.023). There was no difference in vision between medical and combined medical-surgical management, although infection resolution time was shorter for combined intervention (16.8 ± 10.6 vs. 53.7 ± 33.8 days; P = 0.005).

CONCLUSIONS

Infectious scleritis is often successfully treated, but loss of vision or eye removal is common. Poor baseline vision, history of necrotizing scleritis, and fungal etiology were prognostic for worse clinical outcomes. Surgical intervention was associated with quicker resolution compared with medical treatment alone.

[Purulent scleritis following penetrating keratoplasty for acanthamoeba keratitis]

The problem of treating purulent scleral infections, rare but extremely severe complication of ophthalmic surgeries, remains unresolved. This article presents a case of successful surgical treatment of purulent scleritis - interlamellar scleral abscess - that developed in a patient after repeat penetrating keratoplasty performed due to infectious lysis of the transplant. Although the first keratoplasty was performed for acanthamoeba keratitis, there were no signs of acanthamoeba invasion in the transplant at the time of the second surgery. Scleritis manifested as an infiltrate with pus penetrating the anterior chamber and development of keratoiridocyclitis. During surgery, the abscess cavity was opened, irrigated with an antiseptic solution, and drained into the subconjunctival space; the anterior chamber was irrigated with balanced salt solution through a separate paracentesis. No infection recurrences were noted in the postoperative period and the corneal transplant remained clear.

Necrotizing scleritis due to Hormographiella aspergillata

PURPOSE

To report the management and outcome of a case of necrotizing scleritis due to Hormographiella aspergillata.

METHODS

Case report.

RESULTS

A 79-year-old woman developed scleral inflammation following accidental trauma with a gorse plant in her left eye. An abscess formed at the site of the injury, which was surgically drained. Filamentous fungi were identified from the abscess contents, and oral voriconazole and topical voriconazole and natamycin drops were prescribed. Phenotypic analysis confirmed the presence of Hormographiella aspergillata, with low minimum inhibitory concentrations (MIC) for voriconazole and amphotericin B. Two weeks later the patient presented with an area of necrotizing scleritis which required surgical debridement and scleral grafting. Three months later, the scleral inflammation had resolved leaving an area of scleromalacia.

CONCLUSIONS

Hormographiella aspergillata is a common environmental fungus that has recently emerged as a human pathogen and a rare cause of scleritis. To the best of our knowledge, this is the first report of scleritis in which a pure culture of H. aspergillata was obtained. Successful management poses a challenge as there are limited reports on antifungal susceptibility and a combination of medical and surgical treatment is often required.

[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.

Nocardia arthritidis scleritis: A case report

Purpose

This report describes a case and management of a 69-year-old female with infectious scleritis found to be caused by Nocardia arthritidis species.

Observations

Our patient presented with severe constant pain in the left eye (OS) following cataract surgery. She had a pertinent past medical history significant for renal transplantation (on oral tacrolimus, mycophenolate, and prednisone). Slit lamp examination OS (1 month after cataract surgery) demonstrated 3+ injection temporally accompanied by scleral thickening and multiloculated abscesses with purulent drainage from small conjunctival erosions. The abscesses were debrided and sent for gram stain and culture. The patient was treated with repeated subconjunctival injections of antibiotics and an antifungal; topical amphotericin, vancomycin, and amikacin; and oral trimethoprim-sulfamethoxazole (double strength). Two separate gram stains with cultures confirmed the diagnosis and species identification. The patient responded well to repeat subconjunctival injections early on in addition to the prescribed regimen, remaining free of disease at the last follow-up (12 months following presentation).

Conclusions and Importance

This unique case demonstrates infectious scleritis caused by an uncommon Nocardia species (N. arthritidis) that was successfully treated with similar strategies used for other reported Nocardia species. As Nocardia scleritis can lead to adverse outcomes if not treated promptly and properly, it should be considered on the differential diagnoses in an immunocompromised patient who presents with acute ocular symptoms after any recent ocular surgery.