Investigating the genetic, environmental and nutritional factors associated with Tanzanian endemic optic neuropathy (TEON)

Not Applicable

Suspended

• Conditions: Tanzanian endemic optic neuropathy (TEON); Eye Diseases; Optic neuritis

• Registration Number: ISRCTN14292082
• Lead Sponsor: niversity of St Andrews

Brief Summary

2020 OCT findings in https://pubmed.ncbi.nlm.nih.gov/32918043/ (added 30/06/2021)

Detailed Description

Not available

Study Timeline

• Results First Posted: 1900-01-01
• Study Start: 2020-04-29
• Last Update Posted: 12 July 2021
• Study Completion: 2022-02-06

Recruitment & Eligibility

• Status: Suspended
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

Case group:
1. Signed written consent from all participants, prior to undertaking any study procedures
2. Aged 10-34 years
3. The case definition of TEON, as per previous studies, is a bilateral optic neuropathy of subacute, progressive onset with best-corrected visual acuities of 6/9 or worse in both eyes, alongside an acquired colour vision deficiency, in the presence of temporal optic disc pallor (with OCT evidence of corresponding thinning) or optic disc hyperaemia
4. Cases who meet the case definition and have been referred to the Eye Units in Dar es Salaam for further assessment

Control group:
1. Signed written consent from all participants prior to undertaking any study procedures
2. Aged 10-34 years
3. Participants who have had an ophthalmic history, examination and screening and satisfy the classification criteria for not being diagnosed with TEON
4. Controls will, where possible, be first-degree relatives of a case group participant

Exclusion Criteria

1. Cataract in either eye
2. History of ocular trauma
3. Diagnosis of another ocular pathology except refractive error
4. Relative afferent pupillary defect
5. Signs and symptoms suggestive of raised intracranial pressure
6. Existing diagnosis of multiple sclerosis (or any other demyelinating condition)
7. Untreated hypertension
8. Unilateral disease
9. Significant needle phobia
10. Use of oral vitamin supplements
11. Use of amiodarone, linezolid, ethambutol, isoniazid, tetracycline spp, oral chloramphenicol, methotrexate, lithium, metronidazole or omeprazole

Study & Design

• Study Type: Observational
• Study Design: Not specified