Cataracts:
From One Medical Student to Another
page 5
PREOPERATIVE TESTING
Testing performed prior to cataract surgery includes:
- Visual acuity measurement in both dim and bright lighting
- Examination of pupils for a relative afferent pupillary defect
- External eye exam to determine any complicating external factors
- Retinal examination
- Measurement of corneal curvature and axial eye length to calculate IOL power
- Gonioscopy, especially if the plan is to place a lens in the anterior chamber or there are concerns about uveitis or peripheral anterior synechiae
BONUS:
Routine preoperative testing including EKG, complete blood count, electrolytes, creatinine, urea nitrogen and glucose were not found to be beneficial prior to cataract surgery as intraoperative or post operative complication rates were similar for those who did and did not have routine preoperative testing prior to cataract removal (Keay 2009).
COMPLICATING FACTORS
Not all cataract surgeries are born equal. Pre-conditions or complicating factors for cataract surgery include:
- Small pupils hindering view and access to the lens
- Large brow ridge interfering with surgeon's ability to maneuver instruments
- Inability to lie flat or remain still during the procedure
- Zonular laxity increasing the likelihood of lens or IOL dislocation
- Small anterior chamber decreasing work space between the lens and cornea
- Patient on anticoagulants when a clear corneal incision cannot be done
- Patient on alpha-1 blockers for benign prostatic hyperplasia causing "floppy iris" syndrome