Intermediate uveitis

1. Intermediate uveitis

2. Definition
• It includes inflammation occurring at the pars plana and the
peripheral retina.
• Pars planitis is a subset of IU in which snowbanks or
snowballs are prominent features and there is no associated
systemic or infectious disease

3. • Intermediate uveitis: Conditions in which vitritis is the
predominant manifestation.
• Pars planitis: Subset of uveitis in which snowbank or snowball
formation was observed in the absence of an associated infection
or systemic disease.
• Panuveitis: Reserved for inflammation of anterior chamber,
vitreous, retina and/or choroid.
• Retinal vasculitis: Ocular inflammation and retinal vascular
changes are coexistent.

5. EPIDEMIOLOGY
• uncommon, (1%–26% of all cases of uveitis),
• occurs mainly in children and young adults with a mean age at
presentation of 23–31 years
• a bimodal distribution with peaks’ in the 2nd and 5th decades of life
may also be seen.

6. Pathogenesis
• thought to be an autoimmune process, (association between multiple
sclerosis (MS) and IU).
• Suggested by- human leukocyte antigens (HLAs) (in particular HLA DR15),
with IU and MS, the association with sarcoidosis as well as the involvement
of family members with similar HLA
• an infection, such as tuberculosis (TB), syphilis, Lyme disease, cat scratch
disease, or human T-lymphotropic virus type 1 infection, may be the
inciting cause for the immune response.

7. • Histopathological studies of the snowbanks show
• glial and vascular proliferation, as well as lymphocytic infiltration of the
peripheral retinal veins.
• The glial component comprises vitreous collagen and fibrous astrocytes,
• lymphocytic infiltrates are composed mainly of T helper cells.
• These further suggest that IU is an autoimmune process.
• The choroid is relatively spared.

8. SNOWBALLS
SNOWBANKING

9. OCULAR FINDINGS AND COMPLICATIONS
• IU is typically
• bilateral disease with a chronic, slowly progressive course and episodes
of relapses in some patients.
• Symptoms :
• As the primary site of involvement is the vitreous, the most common
symptoms are blurred vision and floaters.
• Pain, photophobia, and redness are less common symptoms and it may
be asymptomatic especially in children

11. • ANTERIOR SEGMENT:
• anterior chamber inflammation -
mild and posterior synechiae is
uncommon (6%–14%).
• A linear configuration of keratic
precipitates, similar to that seen
in autoimmune endotheliopathy,
rarely seen
• There may also be concomitant
corneal edema

12. • POSTERIOR SEGMENT:
• Vitritis, and the vitreous cells may coalesce to form snowballs.
• Snowbanks- which consist of a conglomeration of inflammatory exudates
at the pars plana; found inferiorly.
• inflammatory changes - peripheral vascular sheathing and as a result,
neovascularization of the pars plana (Fig. 7.21.2), retina, or optic disc may
occur.
• Can lead to vitreous hemorrhage, which is more commonly seen in
children, and/or retinal detachment. However, neovascular glaucoma is
rarely seen.

13. • The main causes of visual loss in IU are:
• cystoid macula edema (CME)
• epiretinal membranes (ERMs), and
• cataract formation.
• Glaucoma - direct result of chronic
inflammation or secondary to
corticosteroid therapy.
• Other complications include optic disc
swelling and band keratopathy.

15. DIAGNOSIS
• History and examination and ancillary tests
• presence of skin lesions, which may indicate sarcoidosis, syphilis, TB, or
Lyme disease.
• A history of fever, cough, or night sweats may suggest TB or sarcoidosis.
• Arthralgia may be a symptom of Lyme or Whipple’s disease. If an infectious
cause is suspected, the history should include travel to areas where the
disease is endemic, trekking, or contact with cats, as appropriate.
• Patients with MS may have had previous episodes of neurological
involvement, such as optic neuritis

16. Ancillary tests
• Fundal photography and fluorescein angiography allow for objective
records of extent of vitritis and/or vascular sheathing, respectively.
• Ultrasonography is especially useful in evaluating and monitoring the
progression in eyes where examination of the posterior segment is
limited by media opacity or a small pupil.
• Optical coherence tomography is a valuable tool in assessing macular
changes, such as CME, during the course of the disease as well as
during treatment

17. Diagnostic tests
• complete blood count;
• tuberculin sensitivity test;
• angiotensin-converting enzyme and lysozyme levels;
• serology for syphilis, Lyme disease, TB, and other infectious diseases,
as indicated;
• chest radiography for TB and/or sarcoidosis.
• Magnetic resonance imaging of the brain for white matter lesions
may be advisable in populations with a high prevalence of MS.

18. Medical Management
• first line - Corticosteroids (topical, periocular, intravitreal, or systemic route).
• Topical administration is poor, hence, periocular and intravitreal medications,
the injections often have to be repeated.
• Disadvantages- Cataract progression and elevated intraocular pressures are
common complications of intravitreal corticosteroids.
• Periocular injections carry risks of ocular perforations, and intravitreal
injections pose risks of endophthalmitis, vitreous hemorrhage, and/or retinal
detachment.

20. • If the inflammation is refractory or the patient is unable to tolerate
corticosteroids, various systemic immunosuppressive/immunomodulatory
agents, such as azathioprine, methotrexate, tacrolimus, mycophenolate
mofetil, cyclosporine, or interferon-α2a.
• Tumor necrosis factor (TNF) inhibitors have been used for the
management of intermediate uveitis, particularly when it exhibits
recalcitrance to antimetabolites or calcineurin inhibitors.
• USFDA approved the use of adalimumab for noninfectious intermediate,
posterior uveitis, and panuveitis. Although TNF inhibitors (particularly
adalimumab and infliximab) can be effective in managing inflammation in
intermediate uveitis, given the incidence of MS in intermediate uveitis,
referral to a neurologist for consideration of neuroimaging to rule out
features of a demyelinating process is recommended. Anti-TNF agents can
hasten the development of MS in those predisposed to developing the
neurological disease or make the condition worse if it is present.

21. Surgical Management
• Pars plana vitrectomy in addition to its role in management of the
complications of IU, such as CME, ERM, retinal detachment, or vitreous
hemorrhage.
• By removing inflammatory cells and membranes, it has been found to be
useful in reducing visual loss from CME and ERM, as well as in reducing the
requirement for immunosuppressive therapy.
• Cataract surgery should be undertaken when the eye has been quiet for at
least 3 months; with meticulous surgery as well as perioperative
immunosuppressants or intravitreal corticosteroids, as indicated, at least
79% majority of patients improve by ≥2 Snellen lines.
• The main causes of poor vision are posterior capsule opacification, CME,
ERM, and submacular fibrosis.

22. PROGNOSIS
• The prognosis for most patients with IU is generally good. The mean
visual acuity after 10 years of follow-up was 20/30, with 75%
achieving 20/40 or better visual acuity5,20 and remission was seen in
30%–50% of patients, with younger age being associated with a
better outcome.8,19,21 However, children age <7 years had a less
favorable outcome, with poorer
• vision requiring longer treatment, a lower likelihood of remission, and
a
• higher probability of secondary glaucoma, vitreous hemorrhage, and
need
• for cataract surgery.21