Toric IOLs provide impressive treatment outcomes for the right patients, but like all treatment options they must be used properly to provide the maximum benefit to your patients. Below are my Pearls to help you in the preoperative, interoperative and postoperative stages of Toric IOL treatment.
Goal
Reduction of astigmatism to less than 0.75 D
Surgical Alternatives
Manual LRI/CRI, Laser astigmatic incisions, LASIK/PRK
Preoperative
- Select appropriate candidates
- Counsel patients regarding need for enhancement
- Identify and treat ocular surface disorders (i.e., dry eye, MGD, and ABMD) to obtain accurate measurements
- Check reproducibility and correlation of measurements with multiple devices (keratometry and corneal topography). Old refractions may be helpful but not always
- Accurate biometry (i.e., IOLMaster and Lenstar using appropriate IOL calculation formulas (optimized, newer generation)) to achieve target outcome
- Account for contributions from posterior corneal astigmatism (usually ~0.5 D against-the-rule) and surgically induced astigmatism from cataract incision
- Use appropriate online calculator for toric IOL model
- Pretreat with antibiotic and NSAID 1-3 days prior to surgery
- Mark patient’s eye in upright position to avoid errors from cyclorotation. Alternatively, use imaging device to capture picture of patient’s eye and landmarks (i.e., Verion and Cassini)
Intraoperative
- Meticulous surgical technique
- Appropriately sized, shaped, and centered capsulotomy
- Remove all subincisional cortex and polish capsule
- Remove all OVD from behind IOL
- Watertight incisions
- Confirm IOL centration and proper alignment of IOL markings with steep corneal meridian
- Consider wavefront aberrometry to confirm best astigmatism correction
Postoperative
- Medications: antibiotic for 1-2 weeks; NSAID and steroid for 4-8 weeks depending on risk of CME. I use newer generation brand name drugs because of their better potency and tolerability (i.e., less corneal toxicity).
- Reposition misaligned toric IOLs. Consider using intraoperative wavefront aberrometry or online calculator (www.astigmatismfix.com)
- Treat ocular surface disease
- Diagnose and treat CME and PCO early. Mild PCO can alter postop refraction, and should be treated prior to any enhancement of residual refractive error