Evaluation of the Electroretinogram Pattern (Diopsys® NOVA System) for the Early Diagnosis of Glaucoma

Evaluation of the Electroretinogram Pattern (Diopsys® NOVA System) for the Early Diagnosis of Glaucoma

Glaucoma is a common and potentially blinding disease. It is characterized by an optic nerve damage, a visual field defect and elevated intraocular pressure (IOP).

The loss of retinal nerve fibers is accompanied by functional impairment in the territories corresponding to deficits of the visual field. However, this structure-function relationship is not always found initially. These discrepancies are mainly chronological: the structural damage preceding the functional impairment sometimes of several years

The electroretinogram pattern (ERGP) is an electrophysiological exploration technique that reflects the activity of retinal ganglion cells. It presents itself as an objective field of vision that does not require the active collaboration of the patient. It consists in recording the electrical activity of functional retinal ganglion cells following a light stimulation. Simple (30 minutes maximum), it could improve the detection of early forms of glaucoma. A significant ERGP is also thought to be correlated with peripapillary and macular CNP structural involvement of the ganglionic complex in early forms of glaucoma (MD> -6 dB).

Some results even suggest that ganglion dysfunction could be detected by the ERGP eight years on average before the occurrence of detectable alterations on the RNFL OCT. ERGP is already recognized as a routine examination for monitoring glaucomatous patients (review side in nomenclature and reimbursed by Social Security) but it could therefore be used as a diagnostic tool in very early forms of intraocular hypertonia glaucoma so to objectify signs of preperimetric functional impairment in order to establish a suitable hypotonizing treatment and to improve the prognosis of this disease.

Inclusion Criteria:

• Man and woman age ≥ 18 years

• Francophone

• Patient with medical insurance

• Refraction: sphere ± 5.0 D and cylinder ± 3.0 D

• Pupillary diameter ≥ 3mm

• Early glaucoma patients :

  • Intraocular pressure> 21 mmHg or <21mmHg under treatment
  • Thickness of pathological retinal nerve fibers with at least one affected area (OCT)
  • At least one reliable visual field (false positives, false negatives and fixation losses ≤ 25%) and no artifacts, with Corrected Pattern Standard Deviation (CPSD) pathological in the 5% and Glaucoma Hemifield Pathological test and an early attack (MD> -6dB)

• Patient at risk for glaucoma with:

  • And / or family history of glaucoma
  • and / or intraocular pressure> 21 mmHg
  • and / or retinal nerve fibers (pathological thickness in at least one area on the OCT)
  • and / or reliable visual field (false positives, false negatives and fixation losses ≤ 25%) and without artifact, with pathological Corrected Pattern Standard Deviation (CPSD) in the 5% and Glaucoma Hemifield Pathological Test and an early onset (MD> -6 dB).

Exclusion Criteria:

• Visual acuity below 20/30 (Snellen scale or equivalent on another visual acuity scale)
• Unreliable visual field (false positives, loss of fixation and false negatives> 25%)
• History of intraocular surgery (except uncomplicated cataract surgery)
• Ocular pathology other than associated glaucoma
• Neurological disease affecting the visual field or the optic nerve
• History of macular laser or pan retinal photocoagulation
• Unreliable ERGP pattern
• Offset OCT, unreliable
• Refusal to participate in the study
• Patient under tutorship or curatorship
• Patient deprived of liberty
• Epileptic patient
• Eczema of the eyelids or allergy to one of the components of the electrodes or skin gel allowing the cleaning of the skin before the positioning of the electrodes.