Episcleritis and scleritis are the most common ocular inflammatory manifestation of rheumatoid arthritis.
The management of episcleritis is most often fairly benign, involving oral non-steroidal anti- inflammatory drugs (NSAIDs) and/or topical steroids, topical NSAIDs and artificial tears [3][6]. In refractory or recurrent cases, periocular steroid injections, oral steroids, or, very rarely, DMARDs such as hydroxychloroquine, leflunomide, methotrexate, may be required [3].
Treatment strategies for scleritis classically include NSAIDs as a first line. Steroids, oral and/or intravenous pulse, may be required in more than 70% of patients [3]. Associated topical treatment can involve steroids, NSAIDs, cycloplegics, artificial tears, and/or cyclosporine [3].
DMARDs are reported to be used in half of the patients [3][10]: methotrexate [3][7][10][11], salazosulfapyridine [10], cyclophosphamide [3][7][11], cyclosporine A [7], or azathioprine [7]. To note, in a series of posterior scleritis, patients treated with mycophenolate mofetil (MMF) showed a significantly accelerated time of relapse compared to other patients [8].
Treatment with biologics has been reported effective in small case series and case reports, with successful treatment of refractory cases with infliximab [16][17][18][19][20], adalimumab [21] or certolizumab pegol [22], then in larger series where up to 30% of scleritis patients required biologic response modifiers to achieve control of the inflammation [3][7][10][11]. Based on all the available evidence, recommendations from the American Academy of Ophthalmology were issued in 2014: anti-TNF therapy with infliximab or adalimumab should be considered for patients with scleritis who have failed first-line immunomodulatory therapies [23]. Thus, treatment with infliximab or adalimumab or cyclophosphamide should be proposed to patients who either were already on DMARD at the onset of scleritis or have failed a conventional DMARD, i.e inability to control the inflammation, inability to decrease the steroids to an acceptable level, or multiple recurrences. Anti TNF alpha should also be considered as a first line agent in necrotizing scleritis with direct threat to vision (Figure 8).
Figure 8. Proposition of treatment algorithm and strategy of escalation in rheumatoid arthritis-associated episcleritis and scleritis. DMARDs: disease-modifying anti-rheumatic drugs, HSV: Herpes Simplex Virus, IV: intravenous, MTX: methotrexate, NSAIDs: non-steroidal anti-inflammatory drugs, r/o: rule out, TB: tuberculosis, TNF: Tumor necrosis factor
Rituximab is a monoclonal antibody that recognizes CD-20, an antibody expressed on the surface of mature B lymphocytes, approved for the treatment of moderate-to-severe RA [24]. It has been shown to be another promising agent in the treatment of refractory RA-associated scleritis, reported since 2009 [25]. Adverse effects may include reactivation of viruses, as reported with acute retinal necrosis [26]. The rationale for the use of rituximab in necrotizing scleritis associated with RA is supported by immunohistochemical evidence, from analysis of enucleated eyes with necrotizing scleritis, suggesting that inflammation, in the group of eyes with association to a systemic autoimmune disease, may be driven by B cells, while macrophages could play a role in the necrotizing process [27]. A phase I/II dose ranging randomized trial [28] evaluated treatment with 2 infusions of either 500 mg or 1000 mg at day 1 and day 15, along with intravenous methylprednisolone 100mg, and follow-up every 4 weeks for 24 weeks. In both dosing groups, rituximab was found effective, as in 9 out of 12 patients the inflammation was successfully controlled within 24 weeks of therapy. Peri-infusional disease exacerbations were noted in the 2- to 8 weeks period after infusion, requiring management with short term oral corticosteroid and careful tapering.
Options for local treatments are limited, but subconjunctival injections of triamcinolone or sirolimus could be a valuable option for patients with poor compliance with eyedrops, but also patients with severe comorbidities not eligible to systemic treatment. However, local treatment should not be considered for patients with necrotizing scleritis. Beside the risk of globe perforation, the onset of necrotizing scleritis is a strong indicator that the disease has transformed into a systemic microvasculitic disease, which needs to be addressed with vigorous systemic immunomodulation [29][30].
The onset of necrotizing scleritis may precede or be concurrent with systemic rheumatoid vasculitis. In a patient with RA, even when the disease seems quiescent or stable, the occurrence of necrotizing scleritis or, similarly, PUK, is an evidence of slowly emerging, potentially lethal, visceral vasculitis [30]. In 1976, 27% of patients with necrotizing scleritis were dead within 8 years [6]. Jones et al [31] reported a mortality rate of over 36% in 3 years after a RA-associated scleritis and a 60% incidence of cardio-vascular events. Other reports from the pre-biologics era showed that up to 40% of patients with systemic rheumatoid vasculitis died within 5 years from systemic injuries of vasculitis, cardio-vascular events, or complications of treatments [32][33][34][35][36]. Even before biologics were available, in 1984 Foster et al [29] showed that patients treated aggressively with cyclophosphamide or methotrexate had a favorable life and ocular prognosis compared to patients managed with oral NSAIDs and steroids. The overall incidence of rheumatoid vasculitis has decreased over the past decade, from earlier and more aggressive management of RA as well as from decreased rates of smoking [37][38]. There is no consensus yet as to what sequence of treatment is optimal for ocular manifestations of rheumatoid vasculitis such as necrotizing scleritis or PUK. After infectious causes have been carefully ruled out, including if any doubt a trial antiviral treatment, it seems reasonable to offer intravenous pulse of methylprednisolone, or at least oral steroids, followed by initiation or escalation of immunosuppressants with a low threshold for establishment of a biologic treatment. Agents of choice would be anti TNF alpha for their rapidity of action and safety profile, or rituximab [37][38]. With adequate management of the systemic disease, it seems that the onset of scleritis in a RA patient is not necessarily a life-threatening event anymore. In the recent study of Caimmi et al, even though 39% of episcleritis and 29% of scleritis patients had developed a new extra articular manifestation of RA within 5 years, the survival rate at 10 years was comparable between patients with inflammatory ocular disease and a comparation group of RA patients without ocular disease. Similarly, there was no difference in the incidence of cardio-vascular events between groups of RA patients with or without inflammatory ocular disease [3].
Complications can be seen in 57% of scleritis [3][6] and include decrease in visual acuity, keratitis, cataract, ocular hypertension and glaucoma [10] and scleral thinning and defects. Fortunately, most patients retain a good vision [3][10], unless they develop persistent structural damage to the eye, cystoid macular oedema, peripheral corneal melt, interstitial keratitis, or scleritis-induced astigmatism [7]. In the 1976 series of Watson and Hayreh, 4 patients received corneo-scleral grafts, 2 patients a scleral graft, 3 patients underwent enucleation of the affected eye [6].
The incidence of resolution of ocular disease at 1 year is only 40% in scleritis, as compared to 60% in episcleritis [3]. Patients with scleritis associated with a systemic disease were more likely to have inflammation ongoing for more than 5 years in the study of Bernauer et al [7], and the presence of circulating antibodies (RF, ANA, ANCA) tended to increase the risk of persistent inflammation. Remission, defined as no active inflammation for at least 3 months after discontinuing all immunosuppressive medication [39], was obtained in only 8% of patients with RA-associated scleritis, compared to 30% of patients without RA. When remission was obtained, 86% remained in remission after 1 year of follow-up [39].
Severe, refractory cases of scleritis are a rare manifestation of extra-articular RA. Early recognition and appropriate treatment are crucial and again, good cooperation with the rheumatology or internal medicine specialist will be key. Although no consensus or guidelines exist, many options issued from the rheumatology practice will become available for the treatment of refractory scleritis (Table), once infectious causes are ruled out, allowing a rapid control of the inflammation and avoiding both structural damage to the eye and complications of long-term steroid use. Larger series and trials are needed to determine the best escalation strategy. But already the life-threatening prospect of rheumatoid vasculitis, following the onsetof scleritis, seems to have changed thanks to a more effective and safer control of the systemic inflammation.
This entry is adapted from the peer-reviewed paper 10.3390/jcm10102118