Accuracy of IOL power calculations in the very elderly.

ABSTRACT

BACKGROUND/OBJECTIVES: To analyze the refractive predictability and outcomes of cataract surgery in the very elderly (≥85 years old). SUBJECTS/METHODS: A retrospective case-series performed at the Shiley Eye Institute, University of California San Diego, USA. Electronically pulled data of 2444 surgeries revealed 147 surgeries on 133 very elderly patients. Chart review was conducted for all very elderly and corresponding control patients (75-84 years old). The first operated eyes of patients with final best-corrected visual acuity ≥20/40, axial length (AL) 22-26 mm, and implanted SN60WF IOL were included. Patients with ocular comorbidities and/or intra- or post-operative complications were excluded. Prediction errors of refractive outcome and percentage of eyes within ±0.50D and ±1.00D were compared between the groups for the Holladay 1 and Barrett Universal II (Barrett) formulas. Logistic regression analysis for achievement of ±1.00D was conducted. RESULTS: Final analysis included 90 eyes (n = 44, very elderly, n = 46, control patients). Median absolute refractive error (MedAE) with Holladay 1, but not Barrett formula, was significantly higher in the older group (p = 0.02 and p = 0.07, respectively). The MedAE in the older group was lower using the Barrett compared to Holladay 1 (p = 0.02). Fewer older patients than younger patients achieved refraction within ±0.50D and ±1.00D from goal, using the Holladay 1 (p = 0.049 and p = 0.002 respectively). Logistic regression analysis supported the relationship between Holladay 1 predictive refractive error of >1.00D and patient's age (p = 0.046). CONCLUSIONS: Very elderly patients undergoing cataract surgery may be prone to reduced refractive precision, particularly with utilization of the Holladay 1 formula.