Fig. 5.4 The right eye of a 44-year-old female patient showing multiple confluent areas of choroiditis in a serpiginous pattern

fluid and inflammatory infiltrates in the deeper retinal layers [21]. The differential diagnosis includes sarcoid granulomas, syphilitic gummas, and metastases from malignancies.

A serpiginous-like choroiditis has now been described in patients with systemic tuberculosis (Fig. 5.4). A series of seven such patients was examined and described by Gupta et al. Three patterns of disease were identified: multifocal progressive choroiditis showing a wavelike progression to confluent diffuse choroiditis or diffuse plaque-like choroiditis in an amoeboid pattern. Mycobacterial DNA was identified from the aqueous and vitreous humor via polymerase chain reaction (PCR) studies. A combination of systemic/topical steroids and antitubercular therapy was prescribed for these patients [22].

Orbital Tuberculosis

Tuberculosis of the orbit may either spread from contiguous structures or may spread hematogenously. Orbital lesions are common in young adults (<20 years old), are chronic, slowly progressive, and unilateral, and patients may complain of varying degrees of pain and discomfort. Common signs include proptosis, lid swelling, orbital pain and discomfort, decreased visual

acuity, or visual field abnormalities. Evidence of currently active or healed pulmonary tuberculosis is common on radiological studies. Computed tomography (CT) studies are the investigation of choice and may reveal bony erosions. Orbital fine needle aspiration cytology (FNAC) or biopsies and subsequent histopathological examination frequently reveal the diagnosis. Cultures of orbital tissue may be of help in certain cases. Treatment consists of standard antitubercular therapy along with appropriate surgery. Other reported presentation includes patients who have developed a fistula in an orbital abscess, fungating masses [23] or lesions surrounding the optic nerve [24, 25]. The hallmark “cold abscess”— i.e., an infective mass lesion but without the pain, redness, or warmth of an acute bacterial abscess— may be seen in some patients.

Retinal Tuberculosis

Tuberculosis may involve all the components of the retina including the neural tissue (retinitis) and the retinal vasculature (vasculitis).

Retinal Vascular Disease

Two distinct patterns exist. These include (1) Eales’ disease and (2) tuberculous retinal vasculitis.

Eales’ disease was reported by Henry Eales (1880), who described recurrent retinal and vitreal hemorrhages associated with constipation and epistaxis in a cohort of young men. It is an immune-mediated peripheral retinal periphlebitis that leads to a peripheral retinal ischemia and neovascularization. Eales’ disease largely affects young men between the ages of 20–40. Evidence of previous tuberculous infection in the form of positive Mantoux tests is common, but active pulmonary tuberculosis is uncommon. In a series of 32 patients reported by Renie et al., only two had active pulmonary tuberculosis, whereas positive Mantoux tests were the only significant finding in eight of the remaining [26]. However, mycobacterial DNA has been isolated from the vitreous and surgically excised