The relationship between the mean deviation slope and follow-up intraocular pressure in open-angle glaucoma patients

The purpose of this study was to analyze the relationship between the mean deviation (MD) slope as the progressive rate of visual field defects and the follow-up intraocular pressure (IOP) in open-angle glaucoma (OAG) patients.

This study was a retrospective, nonrandomized comparative study. A total of 287 eyes from 287 Japanese OAG patients were examined. The MD slope of the Humphrey Field Analyzer was calculated and compared with the follow-up IOP. OAG was classified into the high-tension group (>21 mm Hg) and the normal-tension group (≤ 21 mm Hg) on the basis of the highest recorded IOP without treatment, and then the 2 groups were compared. After setting a threshold for the progression rate at -0.3 dB/y, related factors were compared between the fast-progression and slow-progression eyes in each group.

The correlation line between the follow-up IOP and the MD slope was statistically significant in the high-tension group but not in the normal-tension group. Compared with eyes with slow progression, eyes with fast progression in the high-tension group were older and had a higher mean IOP, greater highest and lowest IOPs, and a smaller mean IOP reduction ratio, whereas eyes with fast progression in the normal-tension group had a greater SD of the mean IOP, a larger IOP range, and a greater highest IOP.

Eyes with a faster visual field progression tended to have a higher follow-up IOP in the high-tension group and larger IOP fluctuations in the normal-tension group of OAG patients. We should monitor both the follow-up IOP and fluctuations in IOP to provide a safer and more reliable visual field prognosis for OAG.