Retinal Nerve Fiber Layer Color Research Articles

Reliability of retinal nerve fiber layer color codes of optical coherence tomography in early diagnosis of glaucoma

Reliability of retinal nerve fiber layer color codes of optical coherence tomography in early diagnosis of glaucoma

Agreement of Retinal Nerve Fiber Layer Color Codes between Stratus and Cirrus OCT according to Glaucoma Severity

We assessed the agreement of retinal nerve fiber layer (RNFL) color codes between Stratus and Cirrus optical coherence tomography (OCT) according to the glaucoma severity.We analyzed 184 eyes from 144 subjects with glaucoma and 40 normal subjects. Glaucoma was categorized into three subgroups according to mean deviation of visual field. The agreement of RNFL color code according to the glaucoma severity was assessed using Cohen's kappa value. Red or yellow color codes were defined as abnormal results, while green or white were defined as normal. Disagreement frequency of abnormal color code displayed by 2 OCTs was evaluated.The agreement of RNFL color code was fair to good in all subgroups (κ 0.288-0.887) except for the nasal quadrant, 1 to 4, and the 9 o'clock sectors. In all severity groups, the frequency of disagreement was less than 10% for average, temporal, and inferior sectors. However, Stratus OCT displayed abnormal results, while Cirrus showed normal results for nasal sectors with considerable disagreement proportion (severe 22.5%, moderate 13.2%, and early 13.6%). The disagreement tended to be pronounced in severe glaucoma. On the other hand, Cirrus OCT displayed abnormal results, while Stratus showed normal results for superior sectors (severe 10.0%, moderate 10.5%, and early 15.2%). The frequency was higher in early glaucoma.Considerable color code disagreements were observed in nasal and superior sectors, and the proportion was different according to the glaucoma severity. Color codes of two OCTs could not be considered interchangeable.

Factors Associated with False Positives in Retinal Nerve Fiber Layer Color Codes from Spectral-Domain Optical Coherence Tomography

To determine the factors that contribute to false-positive retinal nerve fiber layer (RNFL) color code results from spectral-domain optical coherence tomography (OCT). A prospective, cross-sectional study. This study included 149 eyes from 77 healthy participants. Participants, who were consecutively enrolled from June 2009 to December 2009, underwent Cirrus OCT. Recorded demographic and clinical factors included age, gender, eye side, intraocular pressure, central corneal thickness, spherical equivalent, axial length, anterior chamber depth, disc area, and the extent of retinal vasculature. An abnormal finding in RNFL color codes was defined as ≥1 yellow or red sectors by quadrant and clock-hour maps and a wedge-shaped color pattern represented by yellow or red in the deviation map. The incidence of false-positive color codes was determined. The influence of clinical and demographic factors on the incidence of false-positive RNFL color codes was assessed using generalized linear mixed model analysis. The false-positive rate for ≥1 of the quadrant, clock-hour, and deviation maps was 26.2%. Longer axial length and smaller disc area were significantly associated with an increased incidence of false-positives when other factors were controlled (odds ratios, 2.422 and 0.165; P = 0.008 and 0.035, respectively). The factors that significantly affected the false-positive RNFL color code results using spectral-domain OCT were axial length and disc area, which may significantly affect the specificity of spectral-domain OCT. Therefore, axial length and disc area should be considered during RNFL thickness profile analysis.