Tuberculous Conjunctivitis in an Anophthalmic Socket.

Tuberculous (TB) conjunctivitis was not an uncommon condition before the early 20(th) century but is currently a rare occurrence, especially in the developed countries. We report a 27-year-old Saudi female who underwent enucleation of the right eye at the age of 20 following a penetrating eye injury. She had a history of miliary TB that was treated at the age of 22. She was presented with chronic purulent discharge from her right an anophthalmic socket for 2 months. Cultures for bacteria and fungi were sterile. There was no response to empirical topical antibiotics and steroids. Direct microscopic examination of conjunctival scrapings with the Ziehl-Neelsen staining revealed no microorganisms. Histopathological examination revealed epithelioid granulomas. Polymerase chain reaction was negative for Mycobacterium tuberculosis DNA. TB conjunctivitis was suspected from the history of miliary TB and presence of epithelioid granulomas. The definitive diagnosis was made after prompt resolution of the ocular signs with no recurrence only after systemic anti-TB therapy.

INTRODUCTION

Ocular tuberculosis (TB) has a wide range of clinical manifestations affecting nearly every ocular tissue.1 These manifestations are caused by direct invasion or by an immunological reaction to the presence or absence of Mycobacterium.2 Ocular clinical manifestations include anterior uveitis, intermediate uveitis, retinal vasculitis, infectious multifocal serpiginoid choroiditis, choroidal tuberculoma, subretinal abscess, scleritis, and optic neuritis.1 Although conjunctival TB is a rare, well-established clinical entity,3 diagnosis of this rare condition is difficult, as it simulates other more common forms of conjunctivitis.

We report a case of chronic purulent discharge from an anophthalmic socket in a 27-year-old female patient. Diagnosis of TB conjunctivitis was based on a positive history of miliary TB, histopathological findings of epithelioid granulomas, and complete response to the systemic anti-TB therapy. To the best of our knowledge, this is the first reported case of TB conjunctivitis in an anophthalmic socket.

CASE REPORT

A 27-year-old Saudi female was presented on April 2012 with chronic purulent discharge for 2 months from the right anophthalmic socket. She had a history of a penetrating injury to the right eye, 7 years earlier that necessitated enucleation. She also had a history of miliary TB at 22 years old that was treated.

On ophthalmic examination, the right socket revealed conjunctival hyperemia with purulent discharge, but no ulceration, nodules, or evidence of pyogenic granulomas were observed. At presentation, the left eye was unremarkable with a visual acuity of 20/20.

Conjunctival swabs were negative for bacterial and fungal cultures. The patient was placed on a course of empirical topical antibiotic and steroids for 1-month with no improvement. Conjunctival scrapings and biopsies were performed. Direct microscopic examination of the conjunctival scrapings revealed no microorganisms with the Ziehl–Neelsen staining. Histopathologic examination of sampled tissue showed fragments of squamous epithelium with an underlying intense lymphoplasmacytic inflammatory infiltrate [Figure 1a], and scattered multiple, small, well-formed epithelioid granulomas with giant cells [Figure 1b and c]. There was no foreign material in the tissue sample. Polymerase chain reaction (PCR) of the material was negative for Mycobacterium tuberculosis DNA.

Figure 1

Histopathologic examination of a sample of tissue: (a) Squamous epithelium with underlying lymphoplasmacytic inflammatory infiltrate (H and E, ×10). (b) Multiple well-formed epithelioid granulomas are present (H and E, ×20). (c) A granuloma with multiple giant cells (H and E, ×20)

The differential diagnosis of granulomatous inflammation includes TB, sarcoidosis, fungal infection, and reaction to foreign material. However, given the patient's history, TB was the most likely cause. Systemic clinical examination was unremarkable. Erythrocyte sedimentation rate and chest radiographs were normal. Mantoux test revealed an induration of 15 mm.

The patient started the triple systemic anti-TB therapy using isoniazid (15 mg/kg daily), rifampicin (12 mg/kg daily), and pyrazinamide (20 mg/kg daily), prescribed for 9 months by the infectious disease team. All ocular signs were resolved within 2 months [Figure 2]. No recurrences were observed during a 24-month follow-up period. Based on these findings, the patient was diagnosed with TB conjunctivitis.

Figure 2

Photograph of the anophthalmic socket, after treatment with systemic anti-tuberculous therapy

DISCUSSION

The prevalence of ocular lesions in TB patients that are attributable to TB is 1.4%.4 Most of the lesions were in the choroid with rare conjunctival involvement.4

In 1882, Eyre reviewed 206 cases of TB conjunctivitis over a period of 30 years. He classified the four types of TB conjunctivitis: Ulcerative, nodular, hypertrophic granulomatous, and pedunculated. Children, adolescents, and young adults were more commonly affected. Most of Eyre's cases were unilateral and the upper lid was the most common location of the lesions. The palpebral conjunctiva was more often involved than the bulbar conjunctiva.3

Few cases of TB conjunctivitis have been reported in the literature, since 1915. The highest numbers were published in 1915 and 1922 that included 48 and 22 cases, respectively. Following those two reports, TB conjunctivitis has been reported in the sporadic case reports.5

The diagnosis of TB conjunctivitis is often challenging because the clinical manifestations are similar to other infectious conditions.6 Definitive diagnosis requires identification of M. tuberculosis organisms in biopsy specimens, either by light microscopy of acid-fast bacilli or by more sensitive culture techniques. Histologic findings of clusters of epithelial cells surrounded by a rim of lymphocytes, with or without Langerhans giant cells and caseation further support the diagnosis.7

Chaurasia et al. described three different criteria for definitive diagnosis of TB conjunctivitis in patients with chronic or recurrent unilateral conjunctivitis - (i) Microbiological criteria: Positive smear or culture or positive PCR for M. tuberculosis; (ii) histopathological criteria: Caseating granulomas or epithelioid giant cells in conjunctival biopsy samples with or without isolation of acid-fast bacilli on special staining; and (iii) clinical criteria: Presence of systemic signs of TB and/or positive response to anti-TB therapy.8

Histopathological examination was performed in our patient because of the high suspicion of TB conjunctivitis. She had a history of miliary TB and a nonresolving discharge despite conventional treatment. The favorable response achieved only after the administration of anti-TB therapy confirmed the diagnosis.

CONCLUSION

Even though TB conjunctivitis is a rare entity, it should always be considered in the presence of a nonresolving purulent discharge from an anophthalmic socket, especially in patients with an inconclusive sign.

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Conflicts of interest

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