bubble_chart Overview

Peripheral uveitis, also known as pars planitis, is a granulomatous uveitis commonly seen in healthy individuals, often presenting as a chronic bilateral disease.

bubble_chart Clinical Manifestations

Based on clinical findings, it can be divided into the following three types:

1. Benign type: The prognosis is relatively good. The exudate disappears after several months of onset, leaving retinal atrophy and peripheral anterior synechia of the iris.

2. Vascular occlusion type: Initially, exudates appear near the ora serrata, with occlusion of peripheral retinal vessels and white sheathing. The lesions gradually progress posteriorly, leading to optic nerve atrophy.

3. Severe type: Large cotton-wool-like exudates are present in the peripheral fundus, forming cyclitic membranes, vitreous opacities accompanied by neovascularization. Traction from the organized membranes may cause hemorrhage or retinal breaks, ultimately leading to retinal detachment.

I. Subjective symptoms

In the early stages, patients may experience floating shadows in their vision, blurred vision, and in severe cases, central vision and peripheral visual field disturbances may occur. Occasional eye pain may also be present.

II. Signs

1. Ciliary congestion: Generally absent or presenting as grade I congestion.

2. The cornea is transparent or shows small, round, suet-like white KP. Aqueous flare or floating inflammatory cells may be observed, along with grayish-yellow exudates in the anterior chamber angle.

3. The iris is usually normal, with rare anterior or posterior synechiae.

4. Fundus findings: Under full mydriasis, anterior vitreous and basal vitreous opacities resembling dust or small granular spheres can be observed, mostly located in the lower part of the eye. Lesions often occur in the pars plana of the ciliary body and the mid-periphery of the choroid, appearing as yellowish-white cotton-ball-like masses when fused. At the ora serrata of the pars plana, gray spherical or large exudates are present anterior to the retina, fusing to form cyclitic membranes that cover the ora serrata and appear as a堤状 (snow bank exudate). Organized tissue from the pars plana extends directly into the vitreous and envelops the posterior lens, forming cyclitic membranes (cyclitis membrana). Macular edema, optic disc edema, peripheral retinal vasculitis, vascular sheathing, and occlusion may also occur. If a clear disease cause can be identified, it is classified as peripheral uveitis.

bubble_chart Treatment Measures

Acute iridocyclitis must be accurately diagnosed and promptly treated to eliminate the risk of blindness and preserve good vision. The treatment principles are as follows:

1. Mydriasis: Once the diagnosis is confirmed, immediate mydriasis (pupil dilation) should be performed. This is the most critical measure in treatment. Any delay may lead to irreversible consequences.

Mydriatic drugs mainly include atropine derivatives, such as 1% atropine eye drops, administered 3–6 times daily. Once the pupil is dilated and inflammation slightly subsides, reduce to 1–2 times daily to maintain dilation until 2 weeks to 1 month after inflammation subsides for consolidation.

The primary effects of atropine are relaxing the ciliary muscle to reduce pressure on the stirred pulse, enhancing blood circulation in the pigment membrane, reducing capillary permeability, decreasing exudation, and exerting anti-inflammatory effects to promote inflammation absorption. Additionally, it dilates the pupil to prevent posterior synechiae or resolve existing adhesions, relieving or alleviating spasms of the pupillary sphincter and ciliary muscles. This allows the eye to rest well and achieves pain relief.

When using atropine, pressure must be applied to the lacrimal sac area to prevent systemic absorption and poisoning, especially in children. Caution is also required for elderly patients, particularly those with narrow anterior chambers or predisposed to glaucoma.

If atropine fails to dilate the pupil, a mixture of 1% cocaine and 0.1% adrenaline (0.3 ml in equal parts) can be injected subconjunctivally near the adhesions for forced mydriasis.

2. Corticosteroid application: Corticosteroids can alleviate and control inflammation, exerting anti-inflammatory and anti-allergic effects, reducing capillary permeability, minimizing tissue edema and exudation, and mitigating fibrous tissue proliferation and collagen deposition. They also suppress allergic reactions. For patients on medication for over 2 weeks, abrupt discontinuation should be avoided; instead, gradual tapering is recommended.

Administration methods include oral medication, eye drops, or subconjunctival injections. Initially, sufficient oral doses should be given to rapidly control inflammation, followed by the minimal maintenance dose until complete resolution of active inflammation.

For anterior uveitis, topical 0.5% cortisone or 0.05% dexamethasone eye drops can be applied 4–5 times daily or hourly, reducing frequency during the convalescent stage. Subconjunctival injections may also be used.

For panuveitis or choroiditis, 0.3 ml of 0.025% dexamethasone can be injected subconjunctivally or beneath the Tenon's capsule, combined with systemic therapy. Severe cases may require intravenous hydrocortisone (200–250 mg) or dexamethasone (5–10 mg) once daily to ensure adequate drug delivery to intraocular tissues.

3. Non-steroidal anti-inflammatory drugs (NSAIDs): Sodium salicylate, phenylbutazone, and indomethacin have analgesic and anti-inflammatory effects, primarily inhibiting elevated prostaglandins in the anterior chamber during uveitis to achieve anti-inflammatory or hypotensive effects. Common regimens include aspirin (0.5 g, 3 times daily) and indomethacin (25 mg, 3 times daily).

4. Antibiotics: For suppurative anterior uveitis, broad-spectrum antibiotics can be administered topically or systemically.

5. Immunotherapy: For severe uveitis and sympathetic ophthalmia unresponsive to steroids, immunosuppressants or immunomodulators may be considered to regulate abnormal immune function. Common immunosuppressants include:

⑴ Cyclophosphamide: Can be used alone or combined with steroids. Oral dosage is 50–100 mg twice daily for 2 weeks per course. Intravenous injection involves dissolving 100–200 mg in 20 ml of saline, administered daily or every other day. Blood tests should be monitored to prevent side effects.

⑵ Ethylenimine (AT-1727): 0.4 g three times daily for 2–3 weeks, followed by a 1-week break, then repeated for 1–2 courses.

(3) Chlorambucil (Leukeran, Chlormethine): The usual starting dose is 2 mg per day, gradually increasing to 2-10 mg per day, with a maximum daily dose not exceeding 20 mg.

Common immunostimulants include levamisole, which is used for individuals with compromised immune function.

6. Hot compress or shortwave therapy: Dilates blood vessels, promotes blood circulation, and enhances the absorption of inflammation.

7. Symptomatic treatment

⑴ For secondary glaucoma, oral acetazolamide can be administered to reduce intraocular pressure.

⑵ For iris bombé, iris puncture or iridectomy may be performed.

⑶ For secondary glaucoma caused by peripheral iris adhesions, peripheral iridectomy may be performed.

⑷ For complicated cataracts, cataract extraction can be performed after inflammation is under control.