Perspectives on Glaucoma

Contact lens sensor may help assess risk of future visual field loss

A study indicated that 24-hour IOP recordings via a contact lens sensor may be associated with prior rates of visual field progression of glaucoma.

Researchers used 24-hour recordings of IOP-related patterns collected via a contact lens sensor (CLS) system. Patients who underwent at least three prior reliable visual field tests were examined.

Participants included 445 patients (445 eyes) with treated, manifest open-angle glaucoma. Of those, 238 were women (53.5%) and 394 were white (88.5%). Mean age at the time of CLS recordings was 68.9 years.

The mean rate of mean deviation change was -0.46 (0.5) dB/y in 5.2 (3) years of follow-up.

The following CLS variables were associated with fast visual field progression: mean peak ratio while awake, number of long peaks during sleep, night bursts ocular pulse frequency SD and night bursts ocular pulse amplitude.

The researchers also noted that these variables performed better than the Goldmann IOP readings taken during follow-up.

“It is ... possible that CLS-derived signals reflect not only the pressure-related component of glaucomatous damage, but also the susceptibility of ocular tissues to pressure,” researchers wrote.

They concluded that, “the CLS may be useful to assess the risk of future functional loss, even in situations when insufficient historical visual field information is available.” – by Abigail Sutton

Disclosures: De Moraes has received research support from Heidelberg Engineering GmBH, Carl Zeiss Meditec Inc. and Topcon Inc. Please see the full study for all remaining authors’ financial disclosures.

A study indicated that 24-hour IOP recordings via a contact lens sensor may be associated with prior rates of visual field progression of glaucoma.

Researchers used 24-hour recordings of IOP-related patterns collected via a contact lens sensor (CLS) system. Patients who underwent at least three prior reliable visual field tests were examined.

Participants included 445 patients (445 eyes) with treated, manifest open-angle glaucoma. Of those, 238 were women (53.5%) and 394 were white (88.5%). Mean age at the time of CLS recordings was 68.9 years.

The mean rate of mean deviation change was -0.46 (0.5) dB/y in 5.2 (3) years of follow-up.

The following CLS variables were associated with fast visual field progression: mean peak ratio while awake, number of long peaks during sleep, night bursts ocular pulse frequency SD and night bursts ocular pulse amplitude.

The researchers also noted that these variables performed better than the Goldmann IOP readings taken during follow-up.

“It is ... possible that CLS-derived signals reflect not only the pressure-related component of glaucomatous damage, but also the susceptibility of ocular tissues to pressure,” researchers wrote.

They concluded that, “the CLS may be useful to assess the risk of future functional loss, even in situations when insufficient historical visual field information is available.” – by Abigail Sutton

Disclosures: De Moraes has received research support from Heidelberg Engineering GmBH, Carl Zeiss Meditec Inc. and Topcon Inc. Please see the full study for all remaining authors’ financial disclosures.

    Perspective
    Mark Eltis

    Mark Eltis

    Ever wonder why some seemingly well-treated glaucoma patients progress quickly, while others are remarkably stable? DeMoraes and colleagues offer insight into this complex question in this retrospective study.

    They found that continuous 24-hour IOP measurement via a contact lens sensor (CLS) can detect unique factors that may be associated with glaucoma progression. IOP spikes that were higher or had very rapid peaks (or both) were most highly associated with previous visual field progression. The CLS not only showed a more complete picture of IOP, but may allow us to project future functional loss even with minimal visual field history.

    These encouraging results suggest that the application of CLS technology to practice might help us manage patients more effectively. However, I have a few reservations.

    First, this is a retrospective analysis, and these results need to be verified via the relative rigor of a prospective study. Second, this device poses financial, technical and possible health concerns. For example, the risks of overnight wear include microbial keratitis. Overall, CLS has the potential to be as revolutionary as pachymetry or OCT to clinical care of glaucoma patients, but further work needs to be completed before it enjoys widespread clinical use.

    • Mark Eltis, OD, FAAO
    • Lecturer, University of Waterloo Private practice, Toronto Member, Optometric Glaucoma Society

    Disclosures: Eltis reports no relevant financial disclosures.