Summary:
Purpose: To evaluate the contribution of Heidelberg Retina Tomograph (HRT)
and blue-on-yellow perimetry (B-Y) for the follow-up and early diagnosis of
glaucoma in patients with ocular hypertension (OHT). We also dealed with the
comparison of visual field (VF) examination by means of the B-Y and white-onwhite
perimetry, correlation between VF indexes and HRT parameters, importance
of the central corneal thickness (CCT) and the comparison of other characteristics
of the study and control groups during the 3-year-study-period.
Patients and methods: Both eyes of 28 patients with OHT (study group, SG) and
15 control subjects (control group, CG) were included in the study. Subjects in
both groups were examined annually. At each visit complete ophthalmological
examination was carried out, including the biomicroscopic evaluation of the
optic disc, aplanation tonometry, HRT II analysis of the optic nerve head (ONH)
and B-Y perimetry. Pachymetry was performed only once at the beginning of
the study.
Results: During the 3-year-follow-up structural changes of the ONH developed
in 2 patients with OHT only. They were not accompanied by VF defects on B-Y
perimetry. Intraocular pressure and CCT were higher in the SG (p<0.01). CCT
significantly and positively correlated with the level of intraocular pressure in
both groups. Mean sensitivity (MS) of the B-Y VF was repeatedly smaller in the
SG compared to the CG (p<0.01). Difference between MS a mean defect (MD) of
the B-Y and white-on-white VF in the SG was significant (p<0.01). The B-Y perimetry
test lasted much longer than standard perimetry. A marked learning effect
was found with B-Y perimetry. Despite significant correlations of follow-up
B-Y perimetry examinations, high test-retest variability was found. No significant
change in topographic parameters of the ONH occurred during the followup
period. HRT displayed low variability of follow-up examinations. No significant
correlation between topographic parameters of the ONH and VF indexes
on B-Y perimetry was found.
Conclusion: In 2 cases of OHT the HRT preceded VF changes on B-Y perimetry.
HRT showed high reproducibility, on the contrary, B-Y perimetry was accompanied
by high variability making the distinction of fluctuation and progression
more difficult. Pachymetry is a very useful tool in patients with OHT.
Key words:
ocular hypertension, Heidelberg retina tomograph, perimetry, pachymetry
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