Condition category
Eye Diseases
Date applied
09/10/2007
Date assigned
05/12/2007
Last edited
18/05/2015
Prospective/Retrospective
Prospectively registered
Overall trial status
Completed
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Nystagmus is an involuntary to and fro movement of the eyes that causes reduced vision. Nystagmus can be acquired in later life, due to neurological disease, or acquired in infancy (infantile nystagmus). There are drugs available to treat nystagmus but there are very few studies to show how effective these medications are. Following on from the use of gabapentin and memantine in acquired nystagmus, we aim to assess whether gabapentin and memantine improve visual acuity and eye movement in infantile nystagmus.

Who can participate?
Patients over the age of 16 years with nystagmus.

What does the study involve?
The study is of a crossover design which means each participant will receive all three treatments (gabapentin, memantine and placebo [dummy drug]) in a random order. Each phase of medication is administered for 17 weeks and there will be a 6-week washout period in between each new treatment. During each phase of medication we will examine the participants five times while the medication is at differing doses. We will examine visual function and eye movement and administer a visual functioning questionnaire at each visit. There will be a total of 16 visits over 69 weeks.

What are the possible benefits and risks of participating?
Possible benefits may be an improvement in vision and/or eye movement. There may also be no direct benefit to the participants but the results may help determine how we treat people with nystagmus in the future. As with any study using medication there may me some unwanted side effects; the most common side effects for gabapentin are drowsiness, dizziness and fatigue and for memantine dizziness, drowsiness and headache.

Where is the study run from?
University of Leicester (UK).

When is the study starting and how long is it expected to run for?
From January 2008 to January 2013.

Who is funding the study?
The Childrens Research Fund (UK).

Who is the main contact?
Prof Irene Gottlob
ig15@le.ac.uk

Trial website

Contact information

Type

Scientific

Primary contact

Prof Irene Gottlob

ORCID ID

Contact details

University of Leicester
Ophthalmology Group
RKCSB
Leicester Royal Infirmary
Leicester
LE2 7LX
United Kingdom
+44 (0)116 258 6291
ig15@le.ac.uk

Additional identifiers

EudraCT number

ClinicalTrials.gov number

Protocol/serial number

Version 2 October 2007

Study information

Scientific title

Pharmacological treatment of nystagmus: a randomised double-masked, placebo-controlled crossover study using gabapentin and memantine

Acronym

Study hypothesis

Nystagmus consists of involuntary to and fro eye movements and severely affects visual function. It occurs in approximately 2.4 in 1000 people. It can be congenital idiopathic, due to retinal diseases and low vision, or associated with neurological diseases. Nystagmus is one of the most distressing eye disorders with symptoms causing blurred vision and oscillopsia (illusory motion of the environment). To date, there is little knowledge in the treatment of nystagmus.

Our hypothesis is that congenital and acquired nystagmus can be treated pharmacologically.

Research questions:
1. How do memantine and gabapentin compare for treatment of nystagmus?
2. Is there a specific nystagmus form, which responds better to pharmacological treatment with memantine or gabapentin?

Please note that the pilot study to this trial is assigned to ISRCTN65414827: Pharmacological Treatment of Congenital Nystagmus (see http://www.controlled-trials.com/ISRCTN65414827).

Ethics approval

Not provided at time of registration – submission pending

Study design

Randomised single-centre double-masked placebo-controlled crossover study

Primary study design

Interventional

Secondary study design

Randomised cross over trial

Trial setting

Hospitals

Trial type

Treatment

Patient information sheet

Condition

Nystagmus

Intervention

180 patients with nystagmus (45 with Idiopathic Infantile Nystagmus [IIN], 45 with nystagmus secondary to albinism, 45 with nystagmus secondary to other eye diseases and 45 with acquired nystagmus) were recruited.

Gabapentin, memantine and placebo will be administered (orally) in random order with 6 week wash out periods in between according to the following scheme:

1. Gabapentin (300 mg units):
Day 0: Examination
Day 1 - 5: 600 mg/day in two divided doses
Day 6 - 10: 900 mg/day in three divided doses
Day 11 - 15: 1200 mg/day in three divided doses
Day 15: Examination
Day 16 - 57: 1200 mg/day in three divided doses
Day 57: Examination
Day 58 - 62: 1500 mg/day in three divided doses
Day 63 - 67: 1800 mg/day in three divided doses
Day 68 - 72: 2100 mg/day in three divided doses
Day 73 - 77: 2400 mg/day in three divided doses
Day 77: Examination
Day 78 - 119: 2400 mg/day in three divided doses
Day 119: Examination

2. Memantine (5 mg units):
Day 0: Examination
Day 1 - 5: 10 mg/day in two divided doses
Day 6 - 10: 15 mg/day in three divided doses
Day 11 - 15: 20 mg/day in three divided doses
Day 15: Examination
Day 16 - 57: 20 mg/day in three divided doses
Day 57: Examination
Day 58 - 62: 25 mg/day in three divided doses
Day 63 - 67: 30 mg/day in three divided doses
Day 68 - 72: 35 mg/day in three divided doses
Day 73 - 77: 40 mg/day in three divided doses
Day 77: Examination
Day 78 - 119: 40 mg/day in three divided doses
Day 119: Examination

Placebo will follow the same regime. The same number of capsules will be administered as the active medication at each point in the scheme.

Total duration time of all treatment arms and washout periods will be 483 days (119 per drug with a washout period of 42 days per drug). Patients will be followed up at just 6 weeks after taking the last medication of the final arm to which they are randomised.

Intervention type

Drug

Phase

Not Applicable

Drug names

Gabapentin, memantine

Primary outcome measures

Change in distance in Logarithm of the Minimum Angle of Resolution (LogMAR) visual acuity between memantine, gabapentin and placebo.

Each of the primary and secondary outcomes will be measured at day 0, 15, 57, 77 and 119 of each treatment arm.

Secondary outcome measures

1. Change in near LogMAR visual acuity between memantine, gabapentin and placebo
2. Change in nystagmus intensity (expanded Nystagmus Acuity Function [NAFX]) function and reading speed will be evaluated as described above at 1.2 m for the different fixation points tested and at near for null point between memantine and gabapentin and placebo
3. Subjective changes in visual function by self-assessment on Visual Function 14 (VF14) questionnaire between memantine and gabapentin and placebo

Each of the primary and secondary outcomes will be measured at day 0, 15, 57, 77 and 119 of each treatment arm.

Overall trial start date

01/01/2008

Overall trial end date

01/01/2013

Reason abandoned

Eligibility

Participant inclusion criteria

1. Patients with congenital or acquired nystagmus
2. Over the age of 16 years

Participant type

Patient

Age group

Adult

Gender

Both

Target number of participants

180 patients with nystagmus

Participant exclusion criteria

1. Contraindication for gabapentin or memantine such as epilepsy, renal impairment, pregnancy or breast-feeding
2. For women of childbearing potential, a pregnancy test will be performed and documentation of adequate contraception during the study drug administration will be obtained
3. Patients on medication incompatible with gabapentin or memantine, such as amantadin

Recruitment start date

01/02/2011

Recruitment end date

01/11/2012

Locations

Countries of recruitment

United Kingdom

Trial participating centre

University of Leicester
Leicester
LE2 7LX
United Kingdom

Sponsor information

Organisation

University Hospitals of Leicester (UK)

Sponsor details

c/o John Hampton
Research and Development
Leicester General Hospital
Leicester
LE5 4PW
United Kingdom
+44 (0)116 249 0490
john.hampton@uhl-tr.nhs.uk

Sponsor type

Hospital/treatment centre

Website

http://www.uhl-tr.nhs.uk/

Funders

Funder type

Charity

Funder name

The Childrens Research Fund (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype

Location

Results and Publications

Publication and dissemination plan

To be confirmed at a later date

Intention to publish date

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes