Big Data Real World Intraocular Pressure Changes Associated With Cataract Surgery

To determine real world changes in intraocular pressure after cataract surgery

Integrated Academic Medical Center – Mayo Clinic - USA

All electronic medical record intraocular pressure (IOP) measurements were organized by laterality and date and associated with cataract surgery events (CPT 66982 or 66984).  The number of days between the IOP measurement and the date of cataract surgery was calculated.  Measurements were categorized in phases as: pre-op (up to 1 day before surgery), day of surgery, post-op day one, post-op less than 30 days after surgery, or post-op over 30 days after surgery.  For patient eyes with over one IOP measurement in a given phase, the mean of all measurements in the phase category was used for further analysis.  Analysis was limited to cataract surgeries having at least one pre-op and one or more over 30 days post-op IOP measurements recorded.

Over 7½ years 855,524 IOP measurments for 45,110 cataract surgeries by 57 surgeons were analyzed.  The mean patient age was 72 years and 58% of patients were female.  The mean IOPs (mmHg) were pre-op 15.0 (SD 6.1), day of surgery 17.4 (SD 22.2), post-op day one 17.9 (SD 8.2), and post-op over 30 days 13.3 (SD 6.0).  The mean >30 day post-op change in IOP after cataract surgery was -2.1 (p<0.001) with 80% of all surgeries experiencing a long-term decrease in IOP.  Higher age (OR 0.960, CI [0.958, 0.963], male gender (OR 0.79 CI[0.754, 0 .830] and higher pre-op IOP (OR 0.597, CI [0.593, 0.601]) were all correlated (p<0.001) with a greater decrease in the over 30 day post-op IOP change.

Real world big data shows that 80% of cataract surgeries experience a mean over 30 day post-op IOP decrease of 2.1 mmHg.  Older patients, males, and those with higher pre-op IOPs experienced a greater IOP decrease.