The Analysis of Refraction and Accommodation of Extreme Myopia with Cataract after Phacoemulsification and IOL Implantation

Background: To assess the refractive status of cataract patients with extreme myopia and to measure their accommodative capability after monofocal IOL implantation. Design: Prospective non-randomized study conducted at Tianjin Medical University Eye Centre. Participants: 18 patients with 34 extreme myopic eyes (≥-10 Diopter, ≥27mm axial length), and 14 patients with 27 non-myopic eyes that had uneventful phacoemulsification and monofocal IOL implantation. Methods: The accommodation amplitude of the two groups was compared preand post-operatively using subjective minus-lenses-to-blur method. In the extreme myopic group, the postoperative target refraction was selected to be myopic, and they were evaluated for predicted postoperative spherical power consistency. Extreme myopic eyes anterior chamber depth was measured by pentacam, and axial length was measured by the immersion vector A/B-scan biometry. All measurements were done preoperatively and at 1, 3, 6 months postoperatively. Main Outcome Measures: Predicted spherical power, amplitude of accommodation, anterior chamber depth, axial length. Results: There was a significant difference between pre and postoperative results of Mean predicted spherical power (P=0.001). The differences between preand postoperative anterior chamber depth measurements were statistically significant (P=0.001). No significant differences were detected between preand postoperative measurements of axial length (P>0.05). There was no significant difference in amplitude of accommodation between the two groups pre or postoperatively ( P>0.05). Conclusions: The study yielded a hyperopic shift of the predicted postoperative spherical power of extreme myopic eyes. No significant difference was observed between extreme myopic and non-myopic eyes in accommodation amplitude preor post-operatively.