Uveitis and Pars Planitis

BASICS


DESCRIPTION


• Intermediate uveitis (IU) is inflammation primarily, of the anterior vitreous, ciliary body, and peripheral retina.


• Pars planitis is a subset of IU for which there is no associated infection or systemic disease.


EPIDEMIOLOGY


• IU comprises ∼15% of all cases of uveitis


• No gender predisposition


• Bilateral in 70–90% of cases, but can be asymmetric


• Pars planitis accounts for 85–90% of intermediate uveitis


– It has a bimodal distribution; the younger age group is 5–15 years, and older age group is 20–40 years


RISK FACTORS


Genetics


Pars planitis has been shown to be associated with HLA-DR15 and HLA-DR51


PATHOPHYSIOLOGY


• The pathophysiology of IU/pars planitis is not well understood


– It is probably an autoimmune reaction against an ocular antigen


• Peripheral retinal veins are the primary foci for inflammation


COMMONLY ASSOCIATED CONDITIONS


• Sarcoidosis


• Multiple sclerosis


• Infectious conditions


– Syphilis


– Tuberculosis


– Lyme’s disease


– Toxocariasis


– HTLV-1


– Bartonella


• Pars planitis has no associated systemic condition


DIAGNOSIS


HISTORY


• Patients present with floaters and decreased vision


• Usually a white, quiet eye, but patients can experience redness and photophobia (more commonly in children).


PHYSICAL EXAM


• Anterior vitreous cellular reaction


• Snowballs, which are aggregates of vitreous cells


• Snowbanks, which are inflammatory pars plana exudates, typically found inferiorly


– Tends to indicate more severe disease


• Vascular tortuosity and peripheral retinal phlebitis


Pediatric Considerations


In children, IU tends to cause greater anterior chamber inflammation


DIAGNOSTIC TESTS & INTERPRETATION


Lab


• Complete blood count (CBC) with differential count


• Erythrocyte sedimentation rate (ESR)


• Purified protein derivative (PPD) skin test


• Angiotensin-converting enzyme (ACE) level, which can be elevated in sarcoidosis


• Consider serologic testing for Lyme’s, syphilis, and Bartonella


Imaging


• Chest X-ray to assess for sarcoidosis and tuberculosis


– If chest X-ray is negative, consider gallium scan or computed tomography (CT) to rule out sarcoidosis if clinical suspicion is high


Diagnostic Procedures/Other


• Fluorescein angiography is helpful in determining presence of cystoid macular edema (CME), retinal phlebitis, and neovascularization.


• Ultrasound biomicroscopy (UBM) can demonstrate pars plana exudates and vitreitis in cases with small pupil


• Diagnostic vitrectomy may be needed in cases where there is suspicion of intraocular lymphoma, endophthalmitis, or in cases refractory to medical therapy


Pathological Findings


• Histologic findings show lymphocytic infiltration of retinal veins


• Pars plana exudates consist of fibroglial tissue with inflammatory cells


DIFFERENTIAL DIAGNOSIS


• Primary central nervous system lymphoma


• Endophthalmitis


• Other uveitic conditions, including Vogt–Koyanagi–Harada disease and Fuch’s heterochromic cyclitis


TREATMENT


MEDICATION


First Line


• Treat underlying cause of disease if infectious etiology is present


• For other cases, corticosteroids are indicated if patient is symptomatic or has vision loss.


– Periocular corticosteroids are first line


– Oral corticosteroids is indicated if local therapy is ineffective, or if there is bilateral severe disease


– Intravitreal injection for refractory cases


Second Line


• Immunomodulatory therapy if corticosteroids fail or side effects cannot be tolerated


– Methotrexate


– Cyclosporine


– Azathioprine


– Mycophenolate mofetil


– Tacrolimus


SURGERY/OTHER PROCEDURES


• If drug therapy fails, cryotherapy and laser photocoagulation can be performed to peripheral retina for ablation of pars plana exudates and neovascularization


• Pars plana vitrectomy (PPV) for chronic inflammation or structural complications such as retinal detachment


– PPV is helpful in reducing CME


ONGOING CARE


FOLLOW-UP RECOMMENDATIONS


• Ophthalmology


• Rheumatology or infectious disease specialist, depending on etiology


PROGNOSIS


• IU generally has a chronic course with exacerbations and remissions, although a small subset of patients have self-limiting disease


– Of all subsets of uveitis, IU tends to have the longest duration, most cases last for 5–15 years but can be longer


• Visual outcome is related to severity of disease and presence of CME


– Pars plana exudate indicates poorer prognosis


• Pars planitis has an overall favorable visual prognosis


COMPLICATIONS


• Chronic inflammation from IU can lead to CME.


• Cataracts result from both chronic inflammation and corticosteroid therapy


– Perioperative use of corticosteroids is needed to control inflammation.


• Glaucoma, both angle closure and open angle


• Band keratopathy


• Peripheral retinal neovascularization


• Vitreous hemorrhage


• Retinal detachment


ADDITIONAL READING


• Bloch-Michel E, Nussenblatt RB. International Uveitis Study Group recommendations for the evaluation of intraocular inflammatory disease. Am J Ophthalmol 1987;103:234–235.


• Jabs DA, Nusenblatt RB, Rosenbaum JT. Standardization of Uveitis nomenclature (SUN) working group. Standardization of uveitis nomenclature for reporting clinical data. Results of the First International Workshop. Am J Ophthalmol 2005;140:509–516.


CODES


ICD9


363.21 Pars planitis


364.3 Unspecified iridocyclitis


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Nov 9, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Uveitis and Pars Planitis
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