Tuberculosis (TB) can silently attack the eye, mimic serious conditions including cancer and eventually cause irreversible loss of vision, a consultant ophthalmologist, Dr Yewande Babalola, has warned.
Babalola gave the warning while delivering a Faculty Lecture, at the College of Medicine, University of Ibadan, titled: ‘Ocular Tuberculosis: Seeing the Unseen Through the Looking Glass.’
Describing ocular tuberculosis as a rare extra-pulmonary manifestation of TB, she said the disease could affect virtually every part of the eye, including the eyelids, orbit, conjunctiva, iris, retina, choroid and optic nerve.
‘Ocular tuberculosis is a great mimicker,’ she said, explaining that its manifestations could resemble those of several other diseases, making diagnosis difficult.
According to Babalola, the eye could serve as a ‘window’ or ‘mirror’ to the body, with findings in the eye sometimes providing clues to disease elsewhere in the body.
‘The eye can be a window to the body; it can also be a mirror to the body. Sometimes, what we see in the eye gives us an indication of what is happening elsewhere in the body,’ she said.
She explained that ocular TB most commonly reaches the eye through the bloodstream, particularly the highly vascularised uvea and choroid.
Babalola cited a Nigerian case reported in 1978 involving a one-year-old boy who was suspected of having retinoblastoma, a serious childhood eye cancer.
‘The child was thought to have retinoblastoma and the eye was removed. But when they did the histopathology, what they found was tuberculosis,’ she said.
According to her, the case underscored the ability of TB to mimic other serious eye conditions and the need for clinicians to consider it when evaluating unusual ocular lesions.
‘It tells us that tuberculosis can mimic cancer in the eye,’ Babalola stated.
She also recalled the case of a 33-year-old HIV-positive woman receiving treatment for drug-resistant pulmonary TB. While one eye was blind, the apparently healthy eye had lesions at the back that indicated ocular TB.
‘This shows that ocular tuberculosis can be symptom-less. The patient may not even know that there is tuberculosis in the eye,’ she said.
Babalola further narrated the case of a 15-year-old boy who had suffered poor vision in both eyes for six years and had been treated for optic atrophy of unknown cause.
A subsequent examination, however, revealed yellowish lesions suggestive of ocular TB.
She said the case highlighted the importance of taking a detailed medical and family history when investigating unexplained visual impairment.
Babalola cautioned that negative tests for pulmonary TB should not necessarily rule out ocular involvement.
‘You can have extra-pulmonary tuberculosis without being able to demonstrate tuberculosis in the sputum,’ she said.
The ophthalmologist expressed concern over the limited research and documentation on ocular TB in Nigeria, saying the paucity of recent studies made it difficult to determine the current burden of the disease in the country.
She said her interest in ocular TB began about 17 years ago during her ophthalmology residency at the University College Hospital, Ibadan, where she rotated through the retina unit under Professor Tunji Oluleye.
Her subsequent exposure to ocular TB, she said, reinforced the need for greater awareness and research into the condition.
To address the knowledge gap, Babalola disclosed that she had developed the POS-OC-TB (Point of Screening for Ocular Tuberculosis) project to improve awareness, screening and referral for ocular tuberculosis.
‘The idea is to educate our physicians and other healthcare workers, screen tuberculosis patients for ocular manifestations and encourage referral to ophthalmologists,’ she said.
She added that healthcare workers needed to understand that TB was not limited to the lungs.
‘We want healthcare workers to know that tuberculosis does not only affect the lungs. It can affect the eye, and sometimes it can affect the eye without the patient having obvious symptoms,’ Babalola said.
She called for stronger collaboration among ophthalmologists, physicians, TB specialists and other healthcare professionals to improve the detection and management of ocular TB.
‘We need to see the unseen. If we look carefully, ask the right questions and examine the patient properly, we may be able to detect these cases early and prevent avoidable visual loss,’ she said.