GDx ECC shows stronger structure-function relationship over VCC in study

Retinal nerve fiber layer images obtained using enhanced corneal compensation show a stronger structure-function relationship with standard automated perimetry visual field sensitivity compared with variable corneal compensation, according to a study.

Thé Anh Mai and colleagues at the Rotterdam Eye Hospital, the Netherlands, used the GDx Nerve Fiber Analyzer (Carl Zeiss Meditec) to measure peripapillary retinal nerve fiber layer (RNFL) retardation with both enhanced corneal compensation (ECC) and variable corneal compensation (VCC). They then compared the structure-function relationship between the measured RNFL retardation and visual field sensitivity, which was measured with standard automated perimetry, according to the study authors.

The study included 33 healthy subjects and 68 patients with primary open-angle glaucoma. Investigators obtained ECC and VCC images, as well as visual field tests, in one eye of each participant.

The researchers found stronger structure-function correlations in images taken with ECC. However, after removing eyes with marked atypical birefringence from analysis, both VCC and ECC showed similar structure-function relationships with visual field sensitivity, according to the study.

The study is published in the April issue of Investigative Ophthalmology and Visual Science.