Correlations Between Digital Planimetry and Optical Coherence Tomography, Confocal Scanning Laser Ophthalmoscopy in Assessment of Optic Disc Parameters

Abstract

In routine clinical practice, laser methods for the evaluation of optic disc parameters are expensive and not accessible for all ophthalmologists; therefore, there is a need for less expensive technique. The aim of this study was to assess correlations between the parameters of the optic disc measured by digital planimetry (DP), optical coherence tomography (OCT), and confocal scanning laser ophthalmoscopy (CSLO) in healthy and glaucoma patients with the normal biometric parameters of the eye. This case-control study enrolled 40 patients with glaucoma and 32 healthy patients with the normal biometric parameters of the eye. All subjects underwent full ophthalmologic examination, digital color optic disc photography, OCT, and CSLO at the same visit. The optic disc was morphometrically analyzed by DP, OCT, and CSLO. Seven optic disc parameters were evaluated. In the glaucoma group, the optic disc and cup areas (r=0.7-0.8, P<0.001) and cup-to-optic disc and rim-to-optic disc area ratios (r=0.7, P<0.001) measured by DP were strongly correlated with those measured by OCT and CSLO, while the horizontal and vertical cup-to-optic disc diameter ratios were found to be moderately correlated (r=0.6-0.7, P<0.001). In healthy patients, the optic disc and cup areas were strongly correlated (r=0.7-8.0, P<0.001). Significant differences in all optic disc parameters, except for the optic disc area, measured by DP, OCT, and CSLO were found between glaucoma and healthy patients. Strong correlations between the parameters of the optic disc measured by DP, OCT, and CSLO were found. There were significant differences in the parameters between healthy and glaucoma eyes measured using DP; therefore, this technique may be used for diagnosis, management, and screening of glaucoma.