Fixation Stability and Refractive Error After Cataract Surgery in Highly Myopic Eyes

To analyze the refractive error in highly myopic eyes after cataract surgery and investigate the possible impact of fixation stability on it.

Secondary data analysis from a previous prospective study.

Clinical data of 98 eyes of 98 consecutive patients with high myopia and 42 eyes of 42 controls, which underwent cataract surgery, were analyzed. Refractive error was calculated 1 month after surgery based on both Sanders-Retzlaff-Kraff theoretic (SRK/T) and Holladay 1 formulas. Fixation stability was evaluated using the Macular Integrity Assessment microperimeter system, which assessed the fixation pattern in terms of 63% and 95% of the bivariate contour ellipse area (BCEA). Multiple linear regression analysis was performed to identify independent predictors of postoperative refractive error.

The highly myopic cataract group had greater hyperopic refractive errors (P < .001 for both formulas) and larger 63% and 95% BCEA values (P = .033 and P = .034) than the control group. In the highly myopic group, the factors 63% or 95% BCEA were positively correlated with the postoperative refractive error (SRK/T formula, r = 0.383, P < .001 and r = 0.320, P = .002, respectively). Multiple linear regression analysis showed that with the SRK/T formula, postoperative refractive error in highly myopic eyes was significantly correlated with axial length (β = 0.491, P < .001), 63% BCEA (β = 0.181, P = .045), and corneal curvature (β = -0.190, P = .024). The refractive error was no longer associated with corneal curvature after using the Holladay 1 formula.

Highly myopic eyes usually had hyperopic refractive errors after cataract surgery. Fixation stability might serve as an important determinant of postoperative refractive errors in this population.