Frequency Doubling Technology and Scanning Laser Tomography in Eyes With Generalized Enlargement of Optic Disc Cupping

Non-standard computer perimetry in the diagnosis of some optic neuropathies

Modern computer perimetry is divided into traditional white stimulus-on-white background, the gold standard of which is perimetry performed by using expert class perimeters Humphrey and Octopus and therefore called standard automatic or automated perimetry (SAP), and non-traditional or non-standard perimetry, which differs, first of all, in a different nature of a stimulus. The article is a review devoted to the assessment of the diagnostic capabilities of non-standard computer perimetry in the form of different variants of perimetry with doubling the spatial frequency (Frequency Doubling Technology Perimetry or FDT perimetry), which is performed by using perimeters of the 1st (Carl Zeiss Humphrey 710 Visual Field / FDT, 1997) and the 2nd (Carl Zeiss Humphrey Matrix / HM 715, 800 Visual Field Analyzer, 2005, 2010) generation. Most authors consider that FDT perimetry is effective in a glaucoma screening and, possibly, in monitoring a glaucomatous process, but only a few authors consider that non-standard perimetry method can be useful in diagnosing optic neuropathies of a different nature.

Agreement between frequency-doubling technology perimetry and Heidelberg retinal tomography 3

PURPOSE

To compare Heidelberg retinal tomography (HRT) 3 and frequency-doubling technology (FDT) perimetry for diagnosis of glaucoma.

METHODS

One eye of each of 117 patients was randomly chosen. The eyes were imaged by HRT3 and tested by FDT. The pattern standard deviation (PSD) and global glaucoma probability score (GPS) were selected as representative output, and sensitivity, specificity, positive predictive value, and negative predictive value determined for each. The agreement between the 2 diagnostic methods was analyzed.

RESULTS

The sensitivity and specificity of HRT3 and FDT perimetry for PSD (65.4 and 62.7 %, respectively) and for GPS (69.2 and 62.7 %, respectively) were similar, as were the positive predictive values (PSD 40.5 %, GPS 41.9 %). However, the 2 methods had only slight diagnostic agreement (κ = 0.112), and this was not significant (P = 0.281).

CONCLUSIONS

FDT perimetry and HRT3 had no significant diagnostic agreement. Thus, the results from both examinations should be considered when determining diagnosis of glaucoma.

[Functional glaucoma diagnosis]

Achromatic perimetry is the gold standard in glaucoma diagnosis for detecting functional defects from glaucomatous optic neuropathy. Because achromatic perimetry is only able to detect scotomas after loss of up to 30-40% of retinal ganglion cells, early diagnosis using this method is rarely possible. Therefore, a lot of new perimetric procedures have been developed in recent years to detect new scotomas at a very early stage. This review summarizes the theoretical background of retinal ganglion cells in order to better understand the theoretical approaches of new perimetric methods. In addition, the most important commercial perimetric devices currently available are presented.