Contact lens sensor may predict IOP changes in open angle glaucoma

A new study by Thibaut Gaboriau and team showed that the features of the 24-hour intraocular pressure (IOP)-related changes, as determined by a contact lens sensor (CLS), may be a risk factor for open angle glaucoma (OAG) development. The findings of this study were published in Investigative Ophthalmology & Visual Science. 

A gradual loss of retinal ganglion cells and optic nerve axons characterizes the neurodegenerative illness glaucoma, which also causes visual field abnormalities and typical expansion of the optic nerve head cup. Even in glaucoma instances where the intraocular pressure (IOP) was determined to be within the normal range by the conventional Goldman applanation tonometry, several investigations have shown that the level of IOP plays a significant impact in the beginning or progression of glaucoma. The goal of this study was to examine the rates of visual field progression in individuals with open angle glaucoma across two groups of 24-hour intraocular pressure-related fluctuations monitoring.

Cross-sectional research was done at the University Hospital of Bordeaux. A contact lens sensor was used to conduct 24-hour monitoring. The mean deviation (MD) parameter of the visual field test was used to compute the progression rate using a linear regression (Octopus; HAAG-STREIT, Switzerland). Two groups of patients were assigned: group 1 had an MD progression rate of less than 0.5 dB/year, and group 2 had an MD progression rate of less than 0.5 dB/year. To compare the output signal between the two groups, an automatic signal-processing algorithm was created and a frequency filtering of the monitoring by wavelet transform analysis was employed. A multivariate classifier was used to determine which group would develop more quickly.

The key findings of this study were:

54 patients' eyes, totaling 54, were included. In group 1 (n = 22), the mean progression rate was 1.09 0.60 dB/year, while in group 2 (n = 32), it was 0.12 0.13 dB/year. 

Group 1 had a substantially greater 24-hour magnitude and absolute area under the monitoring curve than did group 2 (group 1: 343.1 62.3 mV and 8.28 2.10 mV, respectively; group 2: 274.0 75.0 mV and 6.82 2.70 mV, respectively; P 0.05). 

At brief frequency intervals of between 60 and 220 minutes, group 1 likewise had considerably larger magnitude and area under the wavelet curve (P 0.05).

In conclusion, the CLS, together with other predictors of glaucoma development, may aid in early treatment approach adjustment.

Reference: 

Gaboriau, T., Dubois, R., Foucque, B., Malet, F., & Schweitzer, C. (2023). 24-Hour Monitoring of Intraocular Pressure Fluctuations Using a Contact Lens Sensor: Diagnostic Performance for Glaucoma Progression. In Investigative Opthalmology & Visual Science (Vol. 64, Issue 3, p. 3). Association for Research in Vision and Ophthalmology (ARVO). https://doi.org/10.1167/iovs.64.3.3