Long-Term Follow-up of Glaucomatous Fields by Computerized (OCTOPUS-) Perimetry

Summary

Presented here are evaluations of long-term fluctuations of visual field parameters in cases of POAG and ocular hypertension in four groups of patients examined with the OCTOPUS automated perimeter. The first group consists of 35 patients with POAG, who had been followed between 1978/79 and 1984 over a period of 21 to 70 months with programs 33 and 31. The second group was extracted from the first and consists of 19 patients whose disease course could be followed for at least 6 years (mean = 7.5 years). The third group was taken from a pool of 41 patients established in 1982 as being ocular hypertensives and consisted of 27 patients whose disease course could be followed for at least 6 years (mean = 7.4 years) with programs 33 or 31. The fourth group consists of 17 patients with either ocular hypertension or POAG who could be examined twice with program G-1 with one year intervening.

The following was observed:

• 1 The topographic distribution of losses demonstrated the known preference for the upper visual field half, here especially for the nasal quadrant.

• 2 Four patients from the group with ocular hypertension later developed POAG.

• 3 When the term “Total Loss” is taken as a criterium, no obvious deterioration in the POAG group (group II) was observed.

• 4 From this glaucoma group, a smaller number of patients which had been examined with the normal OCTOPUS strategy (program 31) and by which, therefore, the Mean Sensitivity could be determined, showed a deterioration. With the Fast Strategy of program 33 and using the criterium, “Total Loss” resulting therefrom (displaced 4 dB from the age-adjusted average), the important early changes in the vicinity of the threshold remained concealed. This strategy, like all suprathreshold perimetry, should be avoided in glaucoma cases.

• 5 The evaluation of the disease course is rendered impossible by the considerable long-term fluctuations in individual cases. Only when the regression analysis of observations made over a longer period shows a constant and stable course can judgments be made. They are not permitted from one examination to another.

• 6 Considering the exceptionally slow deterioration, extending over years when the IOP is wellmanaged, an increase in examination frequency above 1 to 2 per year is useless.

• 7 The fluctuations cannot be eliminated, even when applying the Field Indices, which frequently behave counter to one another.

• 8 The old, well-known rule still holds true that visual field findings of glaucoma patients can only be evaluated in combination with other parameters such as the IOP, the papilla, the nerve fiber layer, as well as the general medical situation.