Inflammatory Diseases of the Whole Uvea – Tubercular, Syphilitic, Toxoplasma, Sarcoidosis. Ocular Signs in AIDS.
Syphilis - bilateral usually. Clinical Features -
- Iritis - plastic and gummatous variety is seen in congenital syphilis and secondary stage.
- Herxheimer reaction - occurs 24-48 hours after the first therapeutic dose of penicillin due to release of treponemal toxin in the blood.
- Cyclitis - is often associated with iritis.
- Choroiditis - disseminated, anterior and diffuse varieties are commonly seen. Treatment - Systemic course of long acting penicillin is effective.
Tuberculosis - chronic granulomatous infection caused by bovine or human tubercle bacilli. It accounts for 1% of uveitis case in developed countries.
Clinical Features - may cause both anterior and posterior uveitis and also Eales disease.
- Iritis—The metastatic granulomatous type occurs in following forms:
Miliary - multiple yellowish-white nodules are seen near pupillary and ciliary margin particularly in debilitated patients.
Conglomerate tubercle - yellowish-white tumour containing giant cell system is present.
Koeppe’s nodules seen in tuberculosis
Exudative type - allergic in nature, usually recurrent and has a chronic course, large ‘mutton fat’ keratic precipitates are present.
Koeppe’s nodules - minute translucent nodules are seen on the surface of iris at the pupillary margin.
- Choroiditis - two forms: Acute miliary form, Chronic disseminated form.
Treatment - Rifampicin with isoniazid or ethambutol is effective when given for 6 months to 1 year.
Toxoplasmosis – caused by a protozoan infection acquired from cats and rodents.
Clinical Features - signs and symptoms of choroiditis and retinitis are present.
Treatment - Corticosteroids, sulphatriad, pyrimethamine or clindamycin. Photocoagulation may protect macular involvement.
Sarcoidosis - causes acute and chronic iridocyclitis and posterior uveitis. Uveal parotid fever (Heerfordt’s disease) is characteristic.
Ocular Signs in Acquired Immunodeficiency Syndrome (AIDS) -
Etiology - caused by the HIV (Human immunodeficiency virus). The immune complex deposition leads to small vessel disease. This results in cotton wool spots and cytomegalovirus retinitis. Clinical Features - about 50-75% of adult AIDS patients suffer from ocular lesions and complications.
1. Eyelids -
- Herpes zoster ophthalmicus (HZO) - individuals under the age of 50 years who presents with herpes zoster ophthalmicus (HZO) should be suspected of having HIV infection.
- Kaposi’s sarcoma - may present as flat or very slightly raised purple papules on the eyelid. These lesions may be part of a multifocal presentation including conjunctiva or orbit.
- Molluscum contagiosum - a DNA pox virus that causes raised lesions with umbilicated centres, present along the eyelid. This growth may be associated with a follicular conjunctivitis.