New visual field indices of disharmony for early diagnosis of glaucoma, alone or associated with conventional parameters.

Abstract

To evaluate the specificity of new perimetric indices based on harmony, alone and in combination with structural data, for glaucoma detection. In this prospective observational cross-sectional study, one eye of 105 healthy subjects and 97 early and suspect glaucomas were sequentially included and examined with Cirrus optical coherence tomography, twice with OCULUS Smartfield perimeter (SPARK strategy) and twice with Humphrey Analyzer (24-2 SITA-Fast) at the Ophthalmology Department from the University Hospital La Candelaria. Disharmony in the visual field was evaluated including vertical threshold symmetry, threshold rank), and homogeneity (threshold standard deviation from its maximum) using the patient himself/herself as a reference. We also evaluated disharmony in combination with the mean deviation and the pattern standard deviation in a single index (mismatch) and various combinations of morphological and functional indices. Combinations used a new score based on values above certain critical cut-off levels of each index. For 95% specificity, the highest sensitivities were as follows: vertical cup/disc ratio: 28.9%; SPARK threshold rank: 29.9%; and SITA-Fast threshold standard deviation: 28.9%. For the combined indices and 100% specificity, they were 5 SPARK indices mismatch: 10.3%; 5 SITA-Fast indices mismatch: 11.3%; 8 optical coherence tomography indices: 21.9%; 13 SPARK and optical coherence tomography indices: 27.8%; and 13 SITA-Fast and optical coherence tomography indices: 32.0%. Disharmony combined with normative value-based indices and/or optical coherence tomography indices is useful for very specific early diagnosis of glaucoma.