Intraocular pressure before and after cataract surgery in participants of the Melbourne Visual Impairment Project

The purpose of this study was to investigate the effect of cataract surgery on intraocular pressure (IOP) in a cluster-stratified random sample of the population of Victoria, Australia. A total of 3271 participants aged 40 years or older were examined at baseline for the Visual Impairment Project. The baseline study (1992-1994) was followed by a 5-year incidence study. The IOP data were compared between participants who had cataract surgery between the two stages of the study and participants with and without cataract at follow up. The IOP was also compared before and after cataract extraction in glaucoma participants. An eligible 89 non-glaucoma and 24 glaucoma participants had cataract surgery between the two time points. The analyses showed that IOP increases with age in non-operated eyes in both glaucoma and non-glaucoma groups. However, IOP decreased significantly after cataract surgery in eyes with glaucoma but did not change significantly in non-glaucoma participants.