Influence of anterior chamber depth on postoperative refractive outcome in Chinese eyes

Aim or Purpose: This study aims to evaluate the refractive surprise (RS) after cataract surgery with various intraocular lens (IOL) formulas in eyes with very shallow or deep anterior chamber depth (ACD). Design: This is a prospective cohort study of patients from a private ophthalmology practice in Sydney. Methods: Thirty-one patients who had their cataract surgery in 2014 were included. The cohort consists of 20 eyes with ACD < 2.8 mm and 25 eyes with ACD > 3.2 mm. Patients’ demographic variables and their predicted refractive outcomes using the SRK-T, Haigis, Holladay 1, and Holladay 2 IOL formulas were collected. Actual refractive outcomes were obtained from consultations at least one-month postoperatively. RS was calculated from the difference between predicted refraction outcome of IOL formulas and the actual postoperative refraction achieved. Results: The linear correlations between ACD and RS were not significant (p > 0.05). In the group with ACD < 2.8 mm, the mean refractive surprise using SRK-T, Haigis, Holladay 1, and Holladay 2 formulas were -0.191 ± 0.541, -0.189 ± 0.444, -0.201 ± 0.449, and -0.154 ± 0.489 D, respectively. In the group with ACD > 3.2 mm, the mean refractive surprise using the IOL formulas were -1.364 ± 0.541, -1.420 ± 0.541, 0.027 ± 0.394, and -0.045 ± 0.343 D, respectively.  Conclusion: The positive linear correlation between ACD and RS was weak. In eyes with ACD < 2.8 mm, the least RS was found with the Holladay 2 formula, while in eyes with ACD > 3.2 mm, this was found with Holladay 1.