Evaluation of Glaucoma Progression by Means of HRT II Results

Overview

Purpose:
To follow up and statistically evaluate structural and functional changes in primary types of glaucoma, ocular hypertension and persons with large optic disc areas.

Material and methods:
There were 154 eyes (77 patients) enrolled into the prospective study. The follow up period was 3 years, from January 2003 to December 2005. Patients were divided into 5 groups: the primary open angle glaucoma group (PGOU) (54 eyes), the preperimetric form of PGOU group (34 eyes), the ocular hypertension group (OH) with drug therapy (26 eyes), the OH group without drug therapy (18 eyes) and 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 Octopus 101 perimeter. Patients from all groups were tested every 6 months. The statistic analysis was performed with the program Statgraphics plus.

Results:
During 3 years follow up, the significant progression in the HRT II topographic parameters were recorded in the PGOU group (C/D parameter in 41.8 % eyes) and in the preperimetric PGOU group (C/D parameter in 35.3 % eyes). The significant progression was recorded also in the perimetric parameters in the PGOU group (MD parameter in 42.5 % eyes, CLV parameter in 33.3 % eyes). There were no significant changes in the HRT II and perimetric parameters in the OH groups and in the group of persons with large optic disc area during the follow up period. It was found out, the most important topographic HRT II parameters (with high statistical correlation) are C/D ratio, Disc area, Rim area, and Rim volume.

Conclusion:
In spite of local medical therapy and stabilization of IOP values, in advanced stages of glaucoma, the progression of the disease occurred. The 3 years follow up period was too short to reveal any significant changes in the ONH topography in the group with ocular hypertension. HRT II was a reproducible method in the follow up of structural changes of the ONH in all evaluated groups.

Key words:
glaucoma, HRT II, perimetry, ONH