Corneal Biomechanics and Continuous IOP Monitoring Using Soft Contact Lenses in Glaucomatous Patients

Corneal Biomechanics and Continuous IOP Monitoring Using Soft Contact Lenses in Glaucomatous Patients

Ocular hypertension and its fluctuations is a major risk factor of glaucoma onset and progression. In normal eyes, IOP presents a circadian rhythm, but in glaucomatous eyes IOP circadian rhythm is altered and varied widely between patients. To date, the only way to evaluate 24 hour IOP fluctuations is a regular GAT-IOP measurement during a 24-hour hospitalization. This method is expensive and does not reflect physiological conditions because it requires IOP measurements during sleeping periods that may potentially produce artifacts.

Sensimed AG has developed a new medical device SENSIMED Triggerfish® that enables a 24-hour continuous monitoring of IOP fluctuations. As any IOP measurements methods, this medical device might be influenced by corneal properties of the cornea as central corneal thickness, keratometry or biomechanics. We, therefore, investigate the corneal lens tolerance, potential modifications of corneal parameters after a 24-hour wear of the lens, and its influence on data collected during the whole period of analysis. Then we will also analyze the influence of corneal parameters on continuous IOP fluctuations measured with the contact sensor and finally the correlation between data collected and the rate of progression (severity) of glaucoma evaluated with visual field test or optic nerve head damages.

Inclusion Criteria:

• At least 40 year-old

• Signed informed consent

• Visual field defect : at least 2 visual field already done, only the second one is considered for the visual field defect diagnosis, using theses criterion:

  • 3 adjacent points with at least 5db loss
  • Or 1 point with at least 10 db loss
  • Or a 10db difference between two adjacent points on either sides of the nasal horizontal meridian

• Open angle glaucoma patients with a progressive visual field

• For women of childbearing potential, adequate contraception

Exclusion Criteria:

• Corneal dystrophy, scars or corneal surgery
• Iridocorneal angle opening less than 3 using Shaeffer classification
• History of glaucoma surgery
• Any contraindications with the SENSIMED Triggerfish® device, as written in the user manual (active eye disease, severe dry eye, contraindications for silicone contact lens wear…)
• Diabetes
• Sleep Apnea Syndromes
• Cataract surgery
• High myopia
• Pregnancy and lactation
• Patients not able to understand the character and individual consequences of the investigation