Abstract
Purpose: :
To evaluate the ability of optical coherence tomography (OCT) to detect retinal nerve fiber layer (RNFL) loss in patients suspected of having glaucoma.
Methods: :
The study included a cohort of 72 patients longitudinally followed as part of the Diagnostic Innovations in Glaucoma Study (DIGS). All patients were suspected of having glaucoma based on the appearance of the optic disc, but had normal standard automated perimetry visual fields at the time of imaging. Patients were classified based on history of documented stereophotographic evidence of progressive glaucomatous change in the appearance of the optic nerve occurring before the imaging session. RNFL thickness was measured in the two groups using the Fast RNFL thickness protocol of the Stratus OCT (Carl Zeiss Meditec, Inc., Dublin, CA). Areas under the Receiver Operating Characteristic (ROC) curves (AUCs) were calculated for each parameter.
Results: :
Twenty-nine eyes with evidence of glaucomatous progressive optic disc change during follow-up were included in the glaucoma group and 43 eyes observed untreated for an average time of 9.01 +/- 3.09 years without any evidence of progressive damage to the optic nerve were included in the control group. Statistically significant differences were found between the two groups for all the parameters evaluated with the exception of the temporal 8, 9, and 10 clock-hour sectors and the temporal sectoral RNFL thickness. The three parameters with the largest AUCs were the inferior quadrant (AUC = 0.86), the average RNFL thickness (AUC = 0.82), and the 6 o’clock hour sector (AUC = 0.82), although several other parameters showed similar results. The likelihood ratio for an outside-normal limits result (at least one quadrant outside normal limits) was 14.8.
Conclusions: :
Stratus OCT is able to detect early RNFL loss in patients suspected of having glaucoma. These results suggest that OCT RNFL analysis can provide useful information for diagnosing glaucoma when this test is combined with clinical examination of the optic nerve.
Clinical Trial: :
www.clinicaltrials.gov NCT00221897
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • optic nerve