• Users Online: 184
  • Home
  • Print this page
  • Email this page
Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 
Year : 2021  |  Volume : 33  |  Issue : 3  |  Page : 291-298

Optic nerve head-retinal nerve fiber layer analysis with spectral-domain optical coherence tomography of ethambutol-induced ocular toxicity in patients on a daily regime of anti-tubercular therapy

Department of Ophthalmology, Government Medical College, Kozhikode, Kerala, India

Correspondence Address:
Dr. Sanaa Mohammed Konnakkodan
Government Medical College, Kozhikode, Kerala
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/kjo.kjo_162_20

Rights and Permissions

Purpose: This study aims to analyze the clinical profile of patients who presented with visual symptoms after the onset of anti-tubercular therapy (ATT) on daily fixed drug combination and to quantify optic nerve damage in these patients using optical coherence tomography as an objective tool. Study Design and Methodology: This was a cross-sectional observational study of 20 patients who presented with visual symptoms following treatment with daily regime ATT. History was recorded, and detailed ophthalmological evaluation was done, including optic nerve head-retinal nerve fiber layer (ONH-RNFL) analysis using spectral-domain optical coherence tomography (SD-OCT). Data were analyzed with PSPP software. Results: Patients received ethambutol (EMB) at a mean daily dose of 17.61 ± 1.73 mg/kg/day. Of the 40 eyes analyzed, color vision was defective in 35 eyes and contrast sensitivity was reduced in 27 eyes. Mean ONH-RNFL thickness values were 110.8 ± 26.5 μm; 103.7 ± 24.4 μm; 72.6 ± 18 μm; 63.9 ± 13.2 μm; in the inferior, superior, nasal, and temporal quadrants, respectively. Females had more RNFL loss than males. Age, weight, and contrast sensitivity had a positive correlation and log mar vision had a negative correlation with RNFL thickness. Duration of EMB therapy, cumulative dose, and indication for ATT influenced ONH-RNFL thickness. History of renal disease, alcoholism, and smoking were risk factors for RNFL loss. There was a median delay of 21 days in reporting after the development of visual symptoms. Conclusions: Our study population received EMB at a daily dose of >15 mg/kg/day. ONH-RNFL thickness was reduced on SD-OCT. RNFL thickness helps to quantify the role of various risk factors in EMB toxicity, making it a useful tool for objective assessment. Patient education and active screening for the detection of early toxicity are needed to reduce visual impairment and blindness.

Print this article     Email this article
 Next article
 Previous article
 Table of Contents

 Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
 Citation Manager
 Access Statistics
 Reader Comments
 Email Alert *
 Add to My List *
 * Requires registration (Free)

 Article Access Statistics
    PDF Downloaded18    
    Comments [Add]    

Recommend this journal