Scleritis and Episcleritis
Background
Episcleritis1
Refers to the common and usually benign condition characterised by inflammation of
the episclera, which lies between the conjunctiva and the sclera. It is usually an
idiopathic condition but may occasionally occur in the context of underlying disease
or exogenous inflammatory stimuli (see below).
The exact prevalence unknown (as many patients probably do not present), but it
occurs most frequently in younger patients: young adult to fifth decade and is thought
by some to be more common in women.
The most common form is simple episcleritis which is a recurring but self-limiting
inflammation affecting part (simple sectoral episcleritis) or all (simple diffuse
episcleritis) of the episclera lasting 7-10 days before spontaneously resolving.
Less commonly, nodular episcleritis occurs. This is more severe than simple
episcleritis and takes longer to resolve. It is also much more likely to be associated
with systemic disease (see below).
Episcleritis does not progress to true scleritis.
Scleritis2
Refers to the generally much more severe inflammation that occurs throughout the
entire thickness of the sclera.
This is rare, of the order of 0.1% of presentations in the emergency eye clinic,
occurring very slightly more frequently in women and generally in an older age group
than patients with episcleritis, with a mean age of presentation of 52 years.
It is classified according to which part of the sclera is affected. It may be anterior
(98% of cases) or posterior (2% of cases) and there are 4 clearly recognisable groups
of the anterior form:
 Diffuse anterior
- this is the most common (and benign) form characterised by
widespread inflammation of the anterior sclera. It accounts for about 94% of
scleritis cases.
 Nodular - there are erythematous, tender, fixed nodules which, in 20% of
cases, progress onto necrotising scleritis.
 Necrotising - this condition is characterised by extreme pain and marked
scleral damage; it is usually associated with underlying systemic disease.
Where there is associated corneal inflammation, this is also known as
sclerokeratitis.
 Scleromalacia perforans - this is also known as necrotising anterior scleritis
without inflammation and is notable for its lack of symptoms. It is most
frequently associated with rheumatoid arthritis.
Presentation
Episcleritis

Presentation
Acute onset
Mild pain/discomfort
Localised or diffuse red


eye


Uni or bilateral
No associated ocular
symptoms other than
watering and occasional mild
photophobia, vision normal
Past history
 Recurrent
Signs
relating to
presentation
 Sectoral/diffuse redness
episodes
common
 May be associated with
systemic disease but
unusual
 Engorged
episcleral
vessels extending
radially
 Translucent white
Scleritis
 Subacute:
usually
gradual onset
 Severe boring eye pain
often radiating to
forehead, brow and
jaw
 Pain worse with
movement of eye and
at night (may wake
patient)
 Localised or diffuse red
eye
 Uni/bilateral (60%
bilateral in anterior
scleritis and 66%
unilateral in posterior
scleritis)
 Associated watering,
photophobia and
gradual decrease in
vision
 Occasional associated
systemic symptoms
(fever, vomiting,
headache)
 Scleromalacia perforans
may present with
minimal/no symptoms
 Recurrent
episodes
common
 Commonly associated
with systemic disease
which may be severe
Anterior
 Sectoral or diffuse
redness
 Scleral, episcleral and
conjunctival vessels
nodule may be
present witin
inflamed area
 Vision normal
all involved
 Sclera may take on a
blue-ish tinge (best
seen on gross
examination in natural
daylight) ± may be
thin and oedematous
 The globe is tender
 Scleromalacia perforans:
may be enlarging and
coalescing yellow
necrotic nodules ±
scleral thinning
(actual perforation is
rare unless intraocular
pressure is elevated)
Posterior
 Lid oedema
 Proptosis
 Optic disc swelling
 May be a retinal
detachment
Other ocular
signs
 Corneal
involvement is
possible but rare
 10% have an associated
anterior uveitis
The following may occur:
 Corneal involvement
 Glaucoma
 Uveitis
 Retinal detachment
 Cataract formation
 Rapid onset refractive
changes
Differentiating between episcleral and scleral vessels
Episcleral vessels can be moved with a cotton bud. If you apply phenylephrine 2.5%,
they blanch (remember that this will also dilate the pupil). Scleral vessels appear
darker, follow a radial pattern, are immobile and do not blanch.
Differential diagnosis
 Episcleritis/scleritis
 Uveitis
 Conjunctivitis
 Contact
lens related problem
Posterior scleritis has a more extensive list of differential diagnoses including:6
 Optic
neuritis
 Retinal detachment
 Tumours of the choroid
 Orbital inflammatory disease/mass
 Uveal effusion syndrome
 Harada disease
 Intraocular lymphoma
Episcleritis
Investigations
A simple case of episcleritis need not be investigated once a thorough history is taken
and examination is carried out to rule out the unlikely possibility of an associated
systemic disease (see below). If there is a suspicion, biochemical tests should be
performed as guided by concern (e.g. antinuclear antibody, rheumatoid factor, serum
uric acid levels etc).
Associated diseases6,3
 This condition is most commonly idiopathic but 30% is associated with
underlying systemic disease.1
 The most commonly associated systemic disorders are inflammatory bowel
diseases: ulcerative colitis and Crohn's disease.4
 Connective tissue disease such as rheumatoid arthritis, polyarteritis nodosa,
systemic lupus erythematosus and Wegener's granulomatosis have also been
associated with recurring episcleritis.
 Infectious causes are less common but known, including herpes zoster virus,
herpes simplex virus, Lyme disease, syphilis, hepatitis B and Brucellosis.7
 Miscellaneous associations include gout, rosacea, atopy, lymphoma8 and
thyroid eye disease. A foreign body or chemicals may also cause
episcleritis.1
 There are some very rare but documented associations with a number of other
conditions including T-cell leukemia, paraproteinaemia, paraneoplastic
syndromes, Wiskott-Aldrich syndrome, adrenal cortical insufficiency and
progressive hemifacial atrophy.1
Management3
 This is treated with artificial tears alone if symptoms are mild.9
 Where the episode is more severe, a short course of intensive steroids may be
required (under ophthalmologist supervision) and nodular episcleritis may
respond best to oral NSAIDs.4
 It is important to review these patients (a week after initial presentation is
adequate) to ensure resolution of symptoms.
 If the episode is severe, not resolving or if it recurs more than three times, it is
appropriate to refer to the Eye Clinic.
Complications
Involvement of ocular structures is rare: there may occasionally be corneal
involvement (in the form of inflammatory cell infiltrates or oedema) and recurrent
attacks over a period of years may induce some degree of slight scleral thinning.
Complications more commonly occur in those patients who have frequently and
repeatedly need to resort to topical steroid treatment over a number of years and
include cataract formation, ocular hypertension and steroid-induced glaucoma.
Prognosis1
This tends to resolve fully over 1-2 weeks but patients should be aware that episodes
may recur in the same or the fellow eye. If this occurs, it tends to happen at 1-3
monthly intervals.13 The treatment-related complications are the commonest cause of
visual impairment in these patients (hence the need to recognise the benign nature of
this disease and not to overtreat).10
Scleritis
Investigations
Every effort should be made to rule out associated ocular or systemic pathology (see
below). Depending on clinical suspicion, biochemical tests (e.g. full blood count and
inflammatory markers, rheumatoid screen, syphilis screen), ultrasonography of the
globe, plain X rays (chest and sacroiliac joints), MRI or CT imaging (sinuses and
orbits) may be indicated.
The frequency of association and the severity of these associated problems means that
it has to be assumed that there is an underlying cause until proven otherwise.5 In a
patient with no previously diagnosed systemic disease, it is important to rule out
systemic vasculitis as this is the least likely to have been previously diagnosed and it
is a potentially life-threatening disorder.11
Usually, these investigations will be carried out jointly between the ophthalmologists
and other relevant hospital specialists, particularly the rheumatologists.
Associated diseases10
 At least 50% of these patients have a underlying systemic disease and in 15%
of cases, the scleritis is the first presentation of a collagen vascular disorder,
preceding it by one to several months.2
 Scleritis is frequently associated with connective tissue diseases of which
rheumatoid arthritis is by far the most common. Other connective tissue
diseases seen are Wegener's granulomatosis, relapsing polychondritis,
systemic lupus erythematosus, Reiter's syndrome, polyarteritis nodosa and
ankylosing spondylitis.
 Other common associations include gout, Churg-Strauss syndrome and
syphilis.
 It may occur following ocular surgery.12 The aetiology is not exactly known
but it tends to present as intense inflammation adjacent to the surgical site,
usually within 6 months of the procedure. There is an association with the
presence of underlying disease.
 Less common associations include tuberculosis and local infections (usually
spreading from a corneal ulcer) - common culprits are P. aeruginosa, Strep.
pneumoniae, Staph. aureus and varicella zoster. It may also occur with
Lyme disease. Fungal scleritis is very rare.
 More unusual causes include sarcoidosis, hypertension, parasitic infestation,
lymphoma8 and trauma13 or the presence of a foreign body. It has also been
reported in patients taking bisphosphonates2 although the causality has been
recently questioned.14
Management
If you suspect scleritis, make an immediate referral to the ophthalmologists.
 Management
will depend on the type of scleritis and on whether there is any
underlying systemic disease. These patients should all be under specialist
care (usually co-managed by the ophthalmologists and rheumatologists).
 Generally, non-necrotising anterior scleritis will be treated with a progressive
combination of oral NSAIDs (e.g. ibuprofen 400 mg q.d.s.) then oral
prednisolone (e.g. 80 mg o.d.) or a subconjunctival steroid injection such as
triamcinolone acetonide (although this is contra-indicated in necrotising
scleritis and, some say, should be contra-indicated in scleritis altogether3) ±
immunosuppressive therapy such as methotrexate. It may take several
weeks to adjust the treatment to produce a satisfactory result.
 Surgery may be carried out for a diagnostic biopsy and can be required to
address complications such as cataract formation and intractable glaucoma
(see below).
 Necrotising anterior scleritis is managed with systemic steroids and
immunosuppressive therapies and may need surgical intervention if
perforation is impending.10 Rituximab has been tried with success but only
in a very small number of patients to date.15
 Treatment has very limited effect in scleromalacia perforans5,6 but abundant
lubrication may also be added to the regimen.
 Management of posterior scleritis is a little more controversial: young patients
usually respond well to oral NSAIDs6 but elderly patients with associated
disease are managed as with anterior non-necrotising scleritis.
 All patients with scleritis should have any underlying disease addressed.
Complications10
 Scleral thinning
 Ischaemia of the anterior segment of the globe
 Raised intraocular pressure
 Retinal detachment
 Uveitis
 Cataract
 Phthisis (globe atrophy)
Prognosis
Generally, when scleritis originates from a systemic disorder, its course follows that
of the underlying problem.2 However, anterior necrotising scleritis with inflammation
is the most severe and distressing form of the disease. Most patients have an
associated vascular disease. Where there is non-necrotising scleritis, the visual
prognosis is usually reasonable providing that there are no ocular complications (e.g.
uveitis). Otherwise, visual prognosis is poor. There is a mortality rate related to the
underlying condition of ~ 25% within 5 years of the onset of scleritis.6 Posterior
scleritis in patients over 50 is associated with an increased risk of harbouring systemic
disease and suffering visual loss.
Prevention
There are no clear cut prevention measures other than the rigorous control of the
progression of any underlying disease and early treatment of the scleritis to minimise
the risk of visual loss.