Predicting Pseudophakic Refractive Error
What is the best way to predict pseudophakic refractive error in patients who are about to undergo cataract surgery? Investigators recently sought the answer by conducting a prospective case series involving 100 individuals.
Investigators calculated optimum intraocular lens (IOL) power and predicted refractive outcomes using the Barrett Universal II, Hill-RBF, and SRK/T formulas. They then compared the predicted refraction with objective refractive outcomes 1 week, 1 month, and 3 months after surgery. Among the results:
- Average axial length was 23.4 mm, and mean keratometry was 43.9 diopters.
- Average prediction errors at 3 months were 0.50, 0.49, and 0.52 D, respectively.
- Universal II served as a better predictor than the others at 1 week.
- All methods performed similarly at 1 and 3 months.
- RBF predicted the highest proportion of eyes within ±0.25 D at 3 months.
- Keratometric changes primarily occurred 1 to 4 weeks postop.
- A significant hyperopic shift was seen 4 to 12 weeks postop.
Wallace H, Misra S, Li S, McKelvie J. Predicting pseudophakic refractive error: Interplay of biometry prediction error, anterior chamber depth, and changes in corneal curvature. [Published online ahead of print August 2, 2018]. J Cataract Refract Surg. doi: https://doi.org/10.1016/j.jcrs.2018.06.017.