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OpenTrials
Completed

NCT Number: NCT01555827

Retinal Neurodegenerative Signs in Alzheimer's Diseases

A few studies suggest that patients suffering from neurodegenerative diseases (such a multiple sclerosis or Alzheimer's disease (AD)) show decreased thickness of the retinal nerve fiber layer (RNFL), indicating axonal degeneration. High-definition spectral domain optical coherence tomography (SD-OCT), performed without radiation in a few seconds per eye, offers a precise and standardized estimation of this parameter, which could constitute a biomarker for cerebral axonal degeneration. These RNFL deficits might even be the earliest sign of AD, prior to damage of the hippocampal region that impacts memory.

Besides, some associations of AD with some degenerative diseases of the eye (glaucoma, microvascular abnormalities, age-related macular degeneration (AMD)) have also been reported.

It therefore seems interesting to determine whether RNFL thickness, and other ocular parameters, may give some indications for a better detection of AD and cognitive decline in the elderly.

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Key information

Age range

50 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

CHU Bordeaux - hôpital Pellegrin

Bordeaux, 33000, France

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • Inclusion criteria for AD cases:
  • Diagnosis of probable AD, defined according to the NINCDS-ARDRA criteria51
  • Light to moderate severity of the disease, defined by a MMSE score >10 (global evaluation of cognition)
  • Patient aged 50 years or more
  • Patient benefiting from social insurance

Inclusion criteria

for controls:

  • Absence of suspicion of dementia, based on normal performance according to age and educational level at neuropsychological testing defined as:
  • Free recall ≥17 and total recall ≥40 for the Free and Cued Selective Reminding Test (Grober and Buschke test 52) MMSE ≥ norm for age and educational level (defined by mean - 1 SD)
  • Isaac's set test ≥ norm for age and educational level (defined by mean - 1 SD)
  • Matched to age and gender of the cases
  • Patient benefiting from social insurance

Exclusion criteria

Exclusion criteria

for all patients :

  • History of Parkinson's disease or other neurodegenerative disorder
  • History of Horton's disease
  • History of inflammatory neuropathies (in particular Devic's disease, multiple sclerosis)
  • History of vascular ischemic neuropathies and chronic intracranial hypertension
  • History of pituitary tumors
  • Presence of diseases (systemic and/or ocular diseases) or behavioural or cognitive symptoms incompatible with eye examination
  • Known diabetes
  • Person under tutorship or curatorship, person unable to express consent

Additional exclusion criteria for AD cases:

  • Dementia of other cause than AD
  • Severe AD, defined by MMSE score ≤ 10

Additional exclusion criteria for controls:

  • Presence of dementia, of whatever cause

Treatment and study plan

Ophthalmological examination & Questionnaire

Other

The following examinations will be performed, after pupil dilation:

  • Examination with SD-OCT (macular scans, macular volume, peri-papillary scan, retinal autofluorescence, infer-red and red-free imaging)
  • Colour photographs of the retinal, centered on the macula and on the optic nerve (digital non mydriatic retinal camera)
  • Wide-field colour and autofluorescence imaging (Optomap)
  • Measure of intra-ocular pressure (pneumotonometer)

The following informations will be collected through a standardized questionnaire, administered face-to-face during the inclusion visit, or at the moment of the verification of eligibility criteria:

  • Age, gender
  • educational level
  • smoking
  • cardiovascular diseases, current medications
  • scores at neuropsychological tests

Primary outcomes

  1. RNFL thickness measured on a peri-papillary scan of SD-OCT examination.

    Time frame: inclusion visit (day0)

Secondary outcomes

  1. Glaucomatous optic nerve damage observed on colour photographs (cup/disc ratio)

    Time frame: inclusion visit (day0)

  2. Retinal microvascular abnormalities (microaneurysms, micro-hemorrhage, cotton wool spots, arteriovenous nicking), observed on retinal colour photography

    Time frame: inclusion visit (day0)

  3. Macular abnormalities observed on retinal colour photographs (drusen, pigmentary abnormalities, neovascular AMD, atrophic AMD, other retinal diseases)

    Time frame: inclusion visit (day0)

  4. Macular abnormalities observed on macular scans in SD-OCT (drusen, pigmentary abnormalities, neovascular AMD, atrophic AMD, epiretinal membranes, other retinal diseases).

    Time frame: inclusion visit (day0)

  5. Macular abnormalities observed in autofluorescence imaging (increased autofluorescence, decreased autofluorescence, reticular drusen, atrophic AMD, other abnormalities)

    Time frame: inclusion visit (day0)

  6. Macular and peripheral abnormalities diagnosed in wide-field retinal imaging

    Time frame: inclusion visit (day0)

  7. Retinal blood flow velocity (RFI)

    Time frame: inclusion visit (day0)

  8. Intraocular pressure

    Time frame: inclusion visit (day0)

  9. axial length

    Time frame: inclusion visit (day 0)

Sponsors and collaborators

Lead sponsor

University Hospital, Bordeaux

Other

Registry information

Acronym: SIGNAL

Important dates

Study start
2012
Primary completion
2014
Study completion
2014
First posted
Mar 15, 2012
Registry last updated
May 14, 2026

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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