Diagnostic capability of macular parameters of Stratus OCT 3 in detection of early glaucoma

Aim To report the diagnostic capability of Stratus OCT macular parameters in early glaucoma. Material and methods In a cross-sectional observational study, two groups of subjects ( early glaucoma and normals) who satisfied the inclusion and exclusion criteria were recruited. The diagnosis of early glaucoma was based on a glaucomatous appearance of the optic disc correlating with visual-field defects ( fulfilling at least two of three Anderson and Patella criteria, with a mean deviation better than or equal to -6 dB. All patients underwent a complete ophthalmic evaluation including visual-field examination (24-2/30-2 SITA standard programme) and imaging with Stratus OCT 3. The macular thickness map in Stratus OCT includes the fovea, inner macula and outer macula, with diameters of 1, 3 and 6 mm, a total of nine sectors. Sensitivity, specificity, area under the receiving operating characteristic curve (AUROC) and likelihood ratio were calculated for volume and thickness parameters in these nine sectors. Results 56 eyes ( 56 patients) with early glaucoma and 75 eyes ( 75 normals) were analysed. Only two parameters, the outer inferior average volume (p = 0.003) and the outer inferior average thickness (p = 0.002), were statistically significantly lower in the glaucoma group. Outer inferior average volume had a best combination of sensitivity and specificity (56% and 79% respectively). Both outer inferior average volume and thickness parameters yielded the best AUROCs of 0.66. Conclusions Outer inferior macular thickness and volume parameters in early glaucoma are significantly different from normals. The moderate sensitivity and specificity suggest that the role of macular parameters in the diagnosis of early glaucoma is limited.