Posterior inflammatory patterns and immunomodulation

Separate morphology from a final cause

Posterior inflammatory disease can involve retina, choroid, retinal vessels or several tissues. White-dot syndromes describe recognizable patterns rather than one interchangeable condition. Birdshot chorioretinitis, multiple evanescent white-dot syndrome, placoid disease and multifocal choroiditis have different courses and treatment needs. Infection and masquerade disease must remain in the differential before systemic immunosuppression.

Assess symptoms, laterality, course, vitreous cells, vascular leakage, macular fluid and lesion depth. Use optical coherence tomography, fluorescein or indocyanine green angiography and autofluorescence to answer specific questions. Visual acuity alone can underestimate impairment: night vision, contrast, fields and electrophysiology may disclose substantial dysfunction despite a relatively good letter score.

Birdshot and white-dot patterns

Birdshot chorioretinitis typically produces bilateral cream-coloured choroidal lesions with vitreous inflammation and retinal vascular involvement. HLA-A29 is strongly associated and can support a compatible diagnosis, but a positive HLA result in a healthy person is not birdshot. Indocyanine green imaging can reveal choroidal involvement when visible spots are subtle. Macular oedema, vasculitis and functional loss guide treatment and monitoring.

Multiple evanescent white-dot syndrome (MEWDS) commonly presents with unilateral photopsias, blind-spot enlargement and small transient outer-retinal lesions. Many uncomplicated cases recover without systemic immunosuppression. Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) produces larger placoid lesions and may have neurological associations; headache or neurological symptoms require attention rather than dismissal as an incidental viral illness.

Multifocal choroiditis and punctate inner choroidopathy can produce punched-out lesions and secondary choroidal neovascularization. The degree of vitreous inflammation and typical patient profile help distinguish patterns. Treating an active CNV and controlling active inflammation are related but different tasks. Serpiginous-pattern disease requires consideration of tuberculosis-associated and other infectious mimics before immunosuppression.

Sympathetic ophthalmia

Sympathetic ophthalmia is bilateral granulomatous panuveitis after penetrating ocular injury or intraocular surgery. The previously injured eye is the exciting eye and the fellow eye the sympathizing eye. Serous detachments and choroidal thickening may occur. The history helps distinguish it from Vogt–Koyanagi–Harada disease, although both can show diffuse choroidal inflammation.

Urgent specialist treatment aims to suppress inflammation and protect both eyes, often using systemic corticosteroids and steroid-sparing agents. Do not teach that removing an eye by a fixed day count guarantees prevention, or that an eye with useful vision must be sacrificed after the diagnosis. Eye-removal decisions involve visual potential, pain, structural injury and an informed discussion; established bilateral inflammation still requires medical treatment.

Steroid-sparing strategy

Repeated systemic steroids can cause major cumulative toxicity. Consider immunomodulation when inflammation is recurrent, sight-threatening, dependent on substantial corticosteroid exposure or unsuitable for local treatment alone. Conventional agents include methotrexate, mycophenolate, azathioprine and calcineurin inhibitors; selected biologics include adalimumab. The choice follows phenotype, comorbidity, reproductive plans and previous response, with specialist supervision.

Before treatment, assess infection risk, vaccination status and relevant laboratory baselines. TB and hepatitis screening matter for selected biologic pathways. Monitor blood count, liver or renal function as required by the chosen agent, rather than giving every drug the same monitoring schedule. Methotrexate's weekly regimen is a critical safety point: confusing it with daily administration can be catastrophic. Calcineurin inhibitors require attention to blood pressure, renal function and interactions.

Intravitreal or periocular steroids can help selected unilateral or asymmetric inflammation and oedema, but cause cataract, pressure elevation and infection risk. A local implant does not treat every systemic manifestation or remove the need to monitor the fellow eye. Reassess nonresponse for infection, irreversible structural damage, poor adherence or an incorrect diagnosis rather than merely increasing immunosuppression.

Clinical application

A patient with bilateral birdshot lesions, vascular leakage and worsening fields needs activity assessment beyond acuity. A unilateral transient white-dot presentation may need monitoring rather than the same biologic regimen. A patient with bilateral choroidal inflammation following ocular penetration requires urgent consideration of sympathetic ophthalmia. State the evidence for inflammation, the important excluded infection and how the proposed therapy will be monitored.

Sources: SUN birdshot classification study and EMA adalimumab information.

Case: activity despite a quiet anterior chamber

A patient with posterior inflammatory disease has few anterior chamber cells but new retinal vascular leakage and declining function. The quiet anterior chamber does not prove that the posterior disease is controlled. Compare imaging with previous studies, identify infection or a masquerade when the pattern is atypical, and document the specific active lesions. A scar and an active lesion have different implications. If systemic immunomodulation is planned, coordinate infection screening, laboratory monitoring and pregnancy considerations for the selected drug; these requirements vary between agents. Treatment success includes preserved vision and suppression of the relevant posterior activity, while steroid toxicity may still require a change despite apparent inflammatory control. In the clinical station, state what observation establishes activity, what alternative diagnosis needs exclusion and how follow-up will measure response. Avoid choosing a biologic solely from the disease name without the systemic and safety context.