Evaluation of anatomical and visual function for early detection of ethambutol toxicity among tuberculosis patients
AIM: To evaluate if early ethambutol toxicity can be detected by comparing pre - and post - treatment anatomical and visual function using retinal nerve fiber thickness, pattern visual evoked potentials and conventional optic nerve function tests. METHODS:This was a prospective study involving...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Press of International Journal of Ophthalmology (IJO PRESS)
2017
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| Subjects: | |
| Online Access: | http://eprints.usm.my/39006/ http://eprints.usm.my/39006/1/Evaluation_of_anatomical_and_visual_function_for_early.pdf |
| Summary: | AIM: To evaluate if early ethambutol toxicity can be
detected by comparing pre - and post - treatment
anatomical and visual function using retinal nerve fiber
thickness, pattern visual evoked potentials and
conventional optic nerve function tests.
METHODS:This was a prospective study involving 72
eyes of 36 patients treated with ethambutol according to
directly observed treatment short-course(DOTS) strategy
in Hospital Universiti Sains Malaysia, Kelantan, Malaysia.
The visual acuity and optic nerve function tests were
performed by a single investigator. Likewise, Humphrey
automated perimetry, optical coherence tomography
( OCT ) measurement of the retinal nerve fibre layer
(RNFL) and pattern visual evoked potential (PVEP) were
performed by a single technician. The examinations were
performed before initiating ethambutol treatment and 3mo
after that.
RESULTS: There was no change in visual acuity, colour
vision, light brightness, red saturation and fundus
findings pre and post ethambutol. However, there was a
statistically significant deterioration in the mean deviation
of the visual field post treatment (P = 0. 010). There were
also significant changes on OCT and PVEP, with increased
RNFL thickness in all quadrants ( P < 0. 05 ) and PVEP
delayed P100 peak latency and amplitude (P<0. 001).
CONCLUSION: Ethambutol toxicity is a known
complication of tuberculosis treatment. Early detection of
this toxicity may prevent severe irreversible visual loss.
The use of OCT to detect RNFL thickness and PVEP to
assess P100 latency and amplitude can assist in the
detection of subclinical anatomical and visual function
changes prior to development of abnormalities on
conventional optic nerve function tests. |
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