Comparison of biometric predictability and final refraction expected in phacoemulsification surgery with and without trabeculectomy

Abstract Objective: The main purpose of this article is to compare the predictability of biometric results and final refractive outcomes expected in patients undergoing cataract surgery through phacoemulsification with and without associated trabeculectomy. Methods: Cataract patients who have undergone phacoemulsification surgery alone (control group) or associated with trabeculectomy (study group) screened. All surgeries were performed following standard protocol. For enrollment, biometrics calculated by IOL Master (Carl Zeiss Meditec, Inc.) biometry, refraction and intraocular pressure (IOP) before and after surgery were required. Data was compared between groups in addition to the correlation between variation of IOP and final refraction. Results: Thirty eyes per group were enrolled. Only prior IOP (p <0.001), IOP post-surgery (p = 0.01) and the difference in IOP (p <0.001) were statistically significant. Axial length, IOL diopter used, expected spherical refraction by biometrics and astigmatism pre- and post-surgery were similar in both groups (p=0.1; 0.4; 0.4; 0.5 and 0.3, respectively). Spherical predictability by biometrics within 0.25 diopters was noted in both the control group (range 0.06 ± 0.45) and study group (range 0.25 ± 0.97, p = 0.3). There was no statistical significance between groups for the difference between final cylinder and corneal astigmatism (p = 0.9), and the difference between axis of refractive and corneal astigmatism (p = 0.7). Conclusion: The biometric predictability in phacoemulsification surgery and the expected final refraction are significant, andare not modified by trabeculectomy in the combined surgeries.