Cataract surgery appears to have little impact on diurnal IOP fluctuation

This prospective study included 42 South Korean patients (42 eyes) without glaucoma who underwent clear corneal phacoemulsification and IOL implantation. Diurnal IOP was measured one day before surgery and at least four weeks after, every two hours from 9 a.m. to 11 p.m. As expected, mean IOP decreased significantly (12.2±2.5 mm Hg to 10.7±2.1 mm Hg.), but there was no statistically significant change in diurnal IOP fluctuation after surgery.

Whether diurnal IOP fluctuation is an independent risk factor for glaucoma progression is still up for debate, as is the question of whether cataract surgery impacts these IOP fluctuations. Recent evidence shows that cataract surgery lowers IOP in glaucoma patients, particularly those with exfoliative disease, at greater rates and for longer time periods than previously thought.  This has led to discussion among glaucoma specialists about the necessity of combining glaucoma and cataract surgery.   

These results showing no change in diurnal IOP fluctuations in normal eyes after cataract surgery may be important to consider as research proceeds looking at similar parameters in glaucomatous eyes undergoing cataract surgery alone. If further research shows diurnal IOP fluctuation to indeed be an independent risk factor for glaucoma progression, it will likely be even more important. Even though this series is small, short-term, and includes only one ethnicity patients, these results may be used as baseline data for diurnal IOP fluctuation studies in glaucoma patients after cataract surgery.