In acquired measles, prodromal symptoms include persistent cough and fever. Koplik spots can be found on the oral mucosa. A pink macular rash appears in the trunk and spreads to the limbs later on. Retinitis accompanying acquired measles has been described. Manifestations include neuroretinitis with disc edema, macular star formation, attenuated arterioles, and a pigmented paravenous dystrophy [258, 259].

Subacute sclerosing panencephalitis (SSPE) is caused by a variant of the measles virus but differs by alteration or absence of viral M protein and possibly other envelope components. SSPE is a persistent slow viral infection of the CNS including the cerebrum, cerebellum, spinal cord, and the eye. The incubation period is 6–7 years. Around 50% of patients will have ocular signs [260]. Optic disc involvement with papillitis, edema, or atrophy is not uncommon. Retinitis involving the macular is the most consistent finding. Macular gliosis develops late in the disease [261, 262]. Treatment of measles and SSPE is mainly supportive, as no specific treatment has proven beneficial.

16.3.7  Rubella

Rubella virus, a togavirus, is an enveloped, singlestranded virus with icosahedral nucleocapsid. Rubella spreads by droplet infection, is highly contagious, and typically affects children. Rubella can cause congenital or acquired infection.

16.3.7.1  Congenital Rubella Syndrome

The congenital rubella syndrome is a disease caused by maternal infection with rubella in the first trimester with transplacental transmission to the fetus. Infection in the second and third trimester does not result in serious sequelae. The complete syndrome consists of deafness, congenital cataract, cardiac anomalies, and mental retardation. Ocular manifestations of congenital rubella syndrome include cataract, glaucoma, and microphthalmia (Fig. 16.11). Retinal involvement in congenital rubella syndrome is the most common manifestation [263]. The classic findings are of a salt and pepper fundus due to mottled pigmentation of the RPE with alternation between the hyperpigmented and the hypopigmented areas (Fig. 16.12). A diminished foveal reflex is often present. Despite these retinal changes, vision is typically good if the retinal findings are present in isolation.

Fig. 16.11  Cataract secondary to Rubella

Fig. 16.12  Rubella retinopathy. (With courtesy of Richard Lewis, MD)

Subretinal neovascularization and disciform scarring are rare manifestations of congenital infection [264].

Acquired rubella begins with a prodroma of fever, malaise, headache, conjunctivitis, and sometimes lymphadenopathy. After a few days, a rash appears first on the trunk, then spreads to the extremities. Conjunctivitis is the commonest ocular manifestation of acquired rubella. Other manifestations include superficial keratitis and uveitis [265]. A few cases of retinal involvement in acquired rubella have been reported. The lesions were describedasmultifocalanddarkgrayincolor.Fluorescein angiography suggests that the lesions are at the level of the choroid [266, 267]. If the inflammation is severe, corticosteroids may be instituted, but otherwise no ­specific therapy is required.

16.4  Parasitic Infection

A spectrum of parasites is associated with ocular and adnexal disease in children. Parasitism is a state of symbiosis in which the symbiont benefits from the