The Importance of HRT II and Perimeter Octopus 101 in Glaucoma Diseases

Overview

Purpose:
To follow up and statistically evaluate the importance of HRT II (Heidelberg retina tomograph) and perimeter Octopus 101 in glaucoma diseases.

Material and methods:
There were 154 eyes (77 patients) enrolled into prospective study. The follow up period was 3 years, from January 2003 to December 2005. Patients were divided into 3 groups: (1) the primary open angle glaucoma (PGOU) group and the preperimetric form of PGOU group (88 eyes), (2) the ocular hypertension (OH) group with medical therapy and without medical therapy (44 eyes) and (3) the group of persons with large optic disc areas (22 eyes). The structural optic nerve head (ONH) changes were interpreted by means of HRT II equipment and the functional changes were evaluated by means of perimeter Octopus 101 every 6 months. The statistic analysis was performed with the program Statgraphics plus.

Results:
HRT II is a reproducible method to follow up the structural changes of the ONH for its low variability of achieved results in all evaluated groups. Low correlation between MD (mean defect) and CLV (corrected lose variance) parameters in the first and the third groups occurred. The standard automated perimetry was accompanied by greater long-term variability, making it less reproducible, but it is useful method comparing to HRT II. In the group of PGOU patients, significant correlations between MD perimetric parameter and the mean RNFL (retinal nerve fibre layer) thickness parameters were observed by means of HRT II.

Conclusion:
HRT II is not able to replace visual field examination with perimetry, both methods are important in the evaluation of glaucoma patients.

Key words:
glaucoma, HRT II, perimetry, ONH