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OpenTrials
Completed

NCT Number: NCT02939937

Effect of Phenytoin on the Ganglion Cell Layer in Patients With Optic Neuritis

Optic neuritis typically occurs in young (mean age, 32 years), female (77%) patients, and it presents as subacute monocular visual loss that develops over several days.

As yet, treatment with intravenous corticosteroid for optic neuritis had no long-term beneficial effect on vision.

There are a number of factors that contribute to nerve fibre damage including increased level of sodium, so blocking sodium entry could help to protect them against damage.

The main objective of the study is determine whether phenytoin (which blocks sodium entry) can protect nerve fibre and improve final visual function after optic neuritis.

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Key information

Conditions

Optic Neuritis Cranial Nerve Diseases Eye Diseases Nervous System Diseases Optic Nerve Diseases

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Eye Research Center Farabi Hosoital

Tehran, 3542168325, Iran

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • isolated, unilateral, first acute optic neuritis (confirmed by neuroophthalmologist)
  • willing to receive a steroidal regimen
  • no pathologic finding in first oct
  • no pathology and history of optic neuritis in contralateral eye
  • <14 days since onset visual loss

Exclusion criteria

  • Contraindication or known allergy to Phenytoin
  • Use of a calcium channel or sodium channel blocker in the past 2 months
  • Corticosteroid use in the past 2 months
  • Pregnancy
  • Significant cardiac, renal or liver abnormalities
  • Prior clinical episode of optic neuritis in either eye
  • Bilateral acute optic neuritis
  • Known ocular or neurological conditions or abnormalities other than refractive error that impair visual function
  • Refractive error of greater than +5 or -5 diopters
  • Any condition that may interfere with performance of Optical Coherence Tomography (OCT): corneal, lens or fundoscopic abnormality, a co-morbid ocular condition not related to optic neuritis as detected on the OCT reading

Treatment and study plan

Phenytoin

Drug

100 mg phenytoin three time daily for three months, and phenytoin levels will be taken at one and three months later.

Other names: epanutin

Placebo

Drug

100 mg placebo three time daily for three months, and phenytoin levels will be taken at one and three months later.

Primary outcomes

  1. Retinal Ganglion Cell Inner Plexiform Layer Thickness

    Time frame: Measured at baseline and month 1, 6

    ganglion cell inner plexiform layer thickness measure in 8 sectors by Heidelberg spectral-domain Optical Coherence Tomography

  2. Macular Layer Thickness

    Time frame: Measured at baseline and month 1, 6

    macular layer thickness measure in 8 sectors by Heidelberg spectral domain Optical Coherence Tomography

  3. Best Corrected Visual Acuity

    Time frame: at baseline and month 6

    Best corrected visual acuity is converted to logMAR (logarithms of minimum angle of resolution) by statistical calculation.

  4. Visual Field Mean Deviation in Decibel

    Time frame: Measured at baseline and month 6

    The visual field is performed by the Swedish interactive thresholding algorithm standard 24-2 perimeter (Carl Zeiss mediated, Dublin, California).

Secondary outcomes

  1. Retinal Nerve Fibre Layer Thickness in Micrometer

    Time frame: Measured at baseline and month1 ,6

    Retinal nerve fibre layer thickness measure in 8 sectors by Heidelberg spectral-domain Optical Coherence Tomography

Sponsors and collaborators

Lead sponsor

Tehran University of Medical Sciences

Other

Registry information

Official study title

a Phase II Double Blind, Randomized, Placebo Controlled Trial of Effect of Phenytoin on the Ganglion Cell Inner Plexiform Layer (GCIPL) Thickness and Visual Field in Patients With a First Episode of Acute Optic Neuritis

Important dates

Study start
2017
Primary completion
2018
Study completion
2019
First posted
Oct 20, 2016
Registry last updated
Aug 12, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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