Scleritis is a painful inflammatory condition affecting the sclera, the tough white outer wall of the eye. Unlike the more common and milder episcleritis, scleritis involves deeper tissue layers and can threaten vision if it goes untreated. Roughly a third of people who develop it already have or will be diagnosed with an underlying autoimmune disease, which makes the condition a potential warning signal for problems well beyond the eye itself.
What Scleritis Looks and Feels Like
The hallmark of scleritis is deep, boring eye pain that often radiates to the forehead, cheek, or jaw on the affected side. The pain tends to wake people at night and gets worse with eye movement. Unlike a simple case of pink eye, the redness in scleritis has a characteristic violet or bluish hue because the inflammation sits in the deeper scleral tissue rather than in the surface blood vessels. The eye may also be tender to touch through the eyelid.
A common source of confusion is the difference between scleritis and episcleritis, its superficial cousin. Episcleritis causes mild redness with little or no pain and almost always resolves on its own. In a clinical setting, applying phenylephrine eye drops helps tell the two apart: the surface blood vessels in episcleritis blanch and turn pale, while the deeper vessels in scleritis do not respond to the drops.1PubMed Central. Is this a worrisome red eye? Episcleritis in the primary care setting If you have a red eye with significant pain, sensitivity to light, and blurred vision, that combination should prompt an urgent eye exam rather than a wait-and-see approach.
Types of Scleritis
Scleritis comes in several forms, and the type matters a great deal for both treatment and outlook. The main categories are diffuse anterior, nodular anterior, necrotizing, and posterior scleritis.2SAGE Journals. Management of noninfectious scleritis Diffuse anterior is the most common and generally the most manageable: widespread redness and inflammation across the front of the sclera. Nodular anterior scleritis produces distinct tender bumps on the white of the eye. Both of these front-of-the-eye forms respond relatively well to treatment and carry a lower risk of vision loss.
Necrotizing scleritis is the most severe form. It destroys scleral tissue, sometimes leaving the underlying darker uveal tissue visible through the thinned wall. In one Japanese case series, about a third of patients with necrotizing scleritis lost vision, primarily from secondary glaucoma or optic nerve inflammation.3PubMed. Clinical characteristics and ocular complications of patients with scleritis in Japanese At the tissue level, the destruction appears to be driven by an imbalance between enzymes that break down the scleral matrix and the molecules meant to keep them in check. Inflammatory cells like macrophages flood the tissue and release signals that tip the balance toward destruction.4PubMed Central. Increased expression of matrix metalloproteinases in vivo in scleritis tissue and in vitro in cultured human scleral fibroblasts
Posterior scleritis, which affects the back of the eye, deserves special attention because it is often misdiagnosed. You cannot see it by simply looking at the eye. Symptoms tend to include dull aching pain, vision changes, and sometimes double vision. The diagnosis usually depends on imaging, particularly ultrasound, which can show characteristic thickening of the scleral wall behind the eye.
Why Posterior Scleritis Is Easy to Miss
When inflammation sits at the back of the eye, the white of the eye may look completely normal on a routine exam. Studies using B-scan ultrasound have found that the scleral wall in affected eyes is roughly twice as thick as normal, averaging around 1.9 to 2.1 mm compared to about 0.9 to 1.5 mm in unaffected eyes.5Investigative Ophthalmology & Visual Science. Evaluation of Diagnostic Criteria for B-Scan Ultrasonography in Posterior Scleritis6PubMed Central. B-Scan Ultrasonography Findings in Unilateral Posterior Scleritis A classic ultrasound finding called the “T sign,” where fluid collects around the optic nerve and creates a T-shaped shadow, showed up in about 70% of posterior scleritis cases in one series.7PubMed Central. Clinical features and long-term treatment outcome of posterior scleritis
On fundus examination, doctors may see optic disc swelling, choroidal folds, or retinal changes, but roughly one in five patients with posterior scleritis shows no abnormalities at all during a standard look at the back of the eye.8PubMed Central. Clinical features and long-term treatment outcome of posterior scleritis CT or MRI can also help, with most imaged cases showing scleral wall enhancement or thickening. The key takeaway for anyone experiencing unexplained deep eye pain with visual changes is that a normal-looking eye surface does not rule out scleritis. Imaging is often what clinches the diagnosis.
The Autoimmune Connection
Scleritis frequently turns out to be a sign of something going on elsewhere in the body. In a large health-system analysis, about 31% of scleritis patients had an associated autoimmune condition.9PubMed Central. Health system wide “big data” analysis of rheumatologic conditions and scleritis Among autoimmune diseases, rheumatoid arthritis accounted for the largest raw number of scleritis patients, but granulomatosis with polyangiitis (GPA), a type of blood vessel inflammation, had the highest percentage of patients who also had scleritis.10PubMed Central. Health system wide “big data” analysis of rheumatologic conditions and scleritis
A French cohort study tracked scleritis patients over a median of about three and a half years and found that nearly 24% were eventually diagnosed with a systemic disease. GPA was the most common, followed by sarcoidosis, Behçet’s disease, and relapsing polychondritis, among others.11PubMed Central. Scleritis and associated systemic diseases: contribution of systemic examination, follow-up, and additional investigations An additional 12% had an infectious cause identified. Crucially, systemic vasculitis was less likely to have been previously diagnosed than other rheumatic diseases and was more often picked up for the first time during the scleritis workup itself.12Ophthalmology. Evaluation of patients with scleritis for systemic disease In other words, for some people, an inflamed eye is the first clue that a serious autoimmune condition has been quietly developing.
This is why the standard evaluation for scleritis usually includes blood work looking for markers of autoimmune disease, including ANCA testing to screen for vasculitis. About 4% of scleritis patients in one large study tested positive for ANCA without yet having clinical evidence of vasculitis, underscoring the idea that the eye sometimes gets there first.13Ophthalmology. Evaluation of patients with scleritis for systemic disease
When Infection Is the Cause
Not all scleritis is autoimmune. Infectious scleritis is less common but carries its own set of challenges. The most frequent predisposing factor is prior eye surgery, particularly pterygium removal, cataract extraction, and scleral buckle procedures. The use of radiation or antimetabolite drugs during these surgeries further increases risk by thinning the scleral tissue and reducing blood supply, which creates an environment friendlier to microbial growth.14Open Forum Infectious Diseases. Infectious Scleritis: What the ID Clinician Should Know Trauma to the eye involving organic material like soil or plant matter is also a well-recognized trigger, particularly for fungal and bacterial infections.
Distinguishing infectious from autoimmune scleritis matters enormously for treatment: giving immunosuppressive drugs to someone with an active infection will make things worse, not better. Ophthalmologists sometimes biopsy the scleral tissue or take cultures to identify the culprit organism before committing to a treatment plan.
Medications That Can Trigger Scleritis
An underappreciated cause is drug-induced scleritis. Bisphosphonates, the medications commonly prescribed for osteoporosis, are among the better-documented triggers. Both the oral and intravenous forms can cause ocular inflammation presenting as scleritis or orbital inflammation, with intravenous zoledronate being a notable offender.15Clinical Optometry. Drug-Induced Uveitis: Patterns, Pathogenesis and Clinical Implications – Section: Bisphosphonates The French cohort study mentioned earlier also identified two cases of drug-induced scleritis out of 98 patients.16PubMed Central. Scleritis and associated systemic diseases: contribution of systemic examination, follow-up, and additional investigations If you develop a painful red eye within days to weeks of starting a new medication, mentioning the timeline to your eye doctor is worth doing.
Treatment
Treatment follows a step-up approach that depends on how severe the inflammation is and whether an underlying systemic cause has been found. For milder forms like diffuse or nodular anterior scleritis, oral anti-inflammatory drugs are the usual starting point.17PubMed Central. Management of noninfectious scleritis These are not the same as over-the-counter eye drops; prescription-strength oral NSAIDs are needed, and they often need to be taken for weeks.
When NSAIDs do not bring the inflammation under control, oral corticosteroids are added. Steroids work faster and more powerfully, but they come with a long list of side effects when used for extended periods, including elevated eye pressure, cataracts, and the systemic problems of long-term steroid use. For cases that resist both NSAIDs and steroids, or that keep flaring whenever steroids are tapered down, stronger immunosuppressive drugs become necessary.18PubMed Central. Pharmacotherapy of scleritis: current paradigms and future directions These include drugs like methotrexate, mycophenolate, and cyclosporine.
For the most stubborn or severe cases, biologic therapies have become increasingly important. Rituximab, which targets a specific type of immune cell, has shown promise in achieving and maintaining disease control while reducing the need for steroids in refractory scleritis.19PubMed Central. Safety and efficacy of rituximab in refractory noninfectious uveitis and scleritis In necrotizing cases, combining biologics like infliximab and rituximab has been explored, with infliximab providing rapid initial control while waiting for rituximab to take full effect.20PubMed Central. Combined Infliximab and Rituximab in Necrotising Scleritis These treatments require close monitoring and are usually coordinated between an ophthalmologist and a rheumatologist. The trend in the field is clearly moving toward earlier use of targeted biologic agents for cases that do not respond quickly to conventional therapy.21PubMed. Diagnosis and management of non-infectious immune-mediated scleritis: current status and future prospects
Complications and Vision Loss
Left unchecked, scleritis can damage the eye in several ways. In one study, elevated eye pressure was the most common complication, occurring in 41% of patients, followed by inflammation inside the front chamber of the eye at 38%.22PubMed. Clinical characteristics and ocular complications of patients with scleritis in Japanese Vision loss was concentrated in the more aggressive subtypes: about a third of patients with necrotizing or posterior scleritis experienced a decrease in vision, mainly due to secondary glaucoma or inflammation of the optic nerve.
Managing glaucoma in the setting of active scleritis is tricky. The scleral tissue is inflamed and fragile, making surgical options like glaucoma drainage implants riskier than usual. Repeat episodes of necrotizing scleritis can cause exposure of the implant, requiring additional procedures.23PubMed. Ahmed glaucoma valve surgery for necrotizing scleritis with secondary glaucoma This is one of the reasons aggressive control of the underlying inflammation is so critical: preventing structural damage in the first place is far easier than repairing it afterward.
When the sclera has been severely thinned or perforated by necrotizing disease, surgical repair with a scleral patch graft may be needed. Donor scleral tissue is trimmed to fit the defect and sutured in place, then covered with a conjunctival flap or amniotic membrane to promote healing. In one series, structural integrity was preserved in about 77% of grafted eyes.24Eye. Structural and functional outcome of scleral patch graft Newer techniques using overlapping compression sutures over the patch graft have been reported to reduce the risk of further tissue prolapse.25PubMed. Scleral Patch Graft With a Suture Reinforcement Technique in Surgical Management of Necrotizing Scleritis With Ectasia
Scleritis as a Mortality Signal
One of the more sobering findings in the scleritis literature is that, in the context of rheumatoid arthritis, the development of necrotizing scleritis can be a marker for potentially lethal systemic vasculitis. A landmark study found that more than half of rheumatoid arthritis patients who developed necrotizing scleritis and were managed with conventional therapy alone died of a vascular event within ten years.26PubMed. Mortality rate in rheumatoid arthritis patients developing necrotizing scleritis or peripheral ulcerative keratitis. Effects of systemic immunosuppression The eye, the researchers argued, was acting as a sensitive indicator of hidden blood vessel inflammation elsewhere in the body.
More recent data has reinforced the protective value of systemic immunosuppressive treatment. In a study of patients with necrotizing scleritis and a related corneal condition, the estimated mean survival was roughly 10.7 years without immunosuppressive therapy compared to about 24.7 years with it.27PubMed. Ocular complications and mortality in peripheral ulcerative keratitis and necrotising scleritis: The role of systemic immunosuppression Four of the five patients who died during that study were not on immunosuppressive therapy. These numbers underscore that treating necrotizing scleritis aggressively is not just about saving the eye; it may be about saving the patient’s life.
Scleritis in Children
Scleritis is rare in children, and when it does occur, it tends to look somewhat different from the adult version. Posterior scleritis, where inflammation is hidden at the back of the eye, is actually the most common form seen in childhood.28PubMed. Pediatric Scleritis: An Update Anterior and even necrotizing forms can occur as well, though less frequently. Autoimmune associations are present but less common in children than in adults; the recommended workup still includes screening for infections and conditions like ANCA-associated vasculitis, sarcoidosis, and Behçet’s disease. Treatment principles mirror those for adults, with the additional consideration that children’s developing bodies tolerate long-term steroids particularly poorly, making steroid-sparing strategies an even higher priority.
Imaging Advances in Monitoring
Traditionally, assessing scleritis involved clinical examination, ultrasound for posterior cases, and sometimes CT or MRI. A newer tool gaining traction is anterior segment optical coherence tomography (AS-OCT), a non-invasive imaging technique that can produce detailed cross-sectional images of the sclera. AS-OCT can pinpoint the depth of scleral inflammation, helping distinguish scleritis from episcleritis without relying on the phenylephrine drop test.29PubMed. Role of anterior segment optical coherence tomography in scleral diseases: A review It is also proving useful for tracking how well patients are responding to treatment over time, offering both qualitative and quantitative measures of scleral thickness and inflammation.30PubMed Central. Anterior segment optical coherence tomography: A monitoring tool in anterior scleritis
For posterior scleritis, ultrasound remains the workhorse. Comparing the scleral thickness of the symptomatic eye with the other eye can be diagnostic on its own: a difference of 20% or more in scleral wall thickness between the two eyes, or a measurement above about 1.7 mm, has high sensitivity and specificity for the diagnosis.31PubMed Central. B-Scan Ultrasonography Findings in Unilateral Posterior Scleritis
Living with Scleritis and Quality of Life
The psychosocial burden of scleritis is real and tends to be underappreciated. Chronic eye pain, repeated flare-ups, the side effects of immunosuppressive drugs, and anxiety about vision loss all take a toll. A study measuring vision-related quality of life in scleritis patients found that while treatment improved general functioning and visual symptoms to a moderate degree, the improvement in psychosocial well-being was smaller and lagged behind.32PubMed Central. Vision-related quality of life and psychosocial well-being of patients with episcleritis and scleritis: a neglected essence? In practical terms, that means someone whose scleritis has been controlled medically may still struggle with the emotional and social effects of the condition. Bringing up these concerns with your care team is worthwhile; they are a recognized part of the disease, not something you need to power through alone.
Scleritis often requires long-term follow-up, sometimes for years, because the relapse rate is substantial. Most specialists recommend ongoing monitoring even during remission, along with periodic reassessment for underlying autoimmune conditions that may not have been present at the initial diagnosis but could emerge later. The French cohort study illustrates this point: the median follow-up before a systemic disease was identified was over three years, meaning that initial blood work may come back clean while the real diagnosis is still developing.33PubMed Central. Scleritis and associated systemic diseases: contribution of systemic examination, follow-up, and additional investigations Staying in regular contact with both an ophthalmologist and, when appropriate, a rheumatologist gives the best chance of catching complications early and keeping the inflammation under control.