Aims To evaluate the long-term clinical course of normotensive preperimetric glaucoma (PPG).

Methods We retrospectively analysed 130 eyes of 130 patients initially diagnosed as having preperimetric normal tension glaucoma and followed these cases for at least 5 years with reliable visual field (VF) examinations by standard automated perimetry. When the VF defect (VFD) met Anderson-Patella’s criteria on three or more consecutive examinations, and consistently met the criteria on subsequent examinations, we concluded that a glaucomatous VFD was present. Predictive factors for developing a VFD were assessed.

Results Seventy-one eyes (54.6%) developed a glaucomatous VFD during the follow-up period. The mean deviation slope varied from −0.90 to 0.41 dB/year. A Cox proportional hazard model showed that having a greater initial pattern SD (p=0.005), the presence of optic disc haemorrhage (p=0.022) and higher mean intraocular pressure (IOP) prior to developing a VFD (p=0.039) were related to developing a VFD.

Conclusions Our findings confirmed that the mean IOP, but not the IOP fluctuation, is strongly associated with the development of a VFD in cases of PPG.