Different lens power calculation formulas for the prediction of refractive outcome after phacoemulsification with silicone oil removal

Background: Formulas predicting intraocular lens power have not been compared in silicone oil-tamponaded eyes. The study aims to compare six intraocular lens power assessment formulas in silicone oil-tamponaded eyes.

Methods: This prospective study included patients with silicone oil-tamponaded eyes scheduled for silicone oil removal, phacoemulsification, and intraocular lens implantation at Chongqing Aier Eye Hospital (June 2019 to December 2019). Implanted intraocular lens power was used to predict postsurgical spherical equivalence using SRK/T, Holladay 1, Holladay 2, Haigis, Hoffer Q, and Barrett Universal II, and assess those formula's predictive accuracy with predictive error.

Results: The analysis included 47 eyes in 47 patients (28 and 19 eyes with normal and long axial length, respectively). Postoperative spherical equivalence at 6 months in normal and long axial length eyes was - 0.6 ± 0.96 and - 0.8 ± 1.52 D, respectively. Predictive error values for SRK/T, Holladay 1, Holladay 2, Haigis, and Hoffer Q and Barrett Universal II were - 0.18 ± 0.92, - 0.15 ± 0.88, - 0.06 ± 0.94, - 0.15 ± 0.87, and - 0.05 ± 0.90 D and - 0.06 ± 0.90, respectively, for normal axial length eyes and 0.15 ± 1.16, 0.46 ± 1.17, 0.28 ± 1.11, - 0.04 ± 1.12, 0.49 ± 1.09 D and 0.11 ± 0.99, respectively, for long axial length eyes. For normal axial length eyes, predicted outcomes were similar to actual outcomes for all formulas. For long axial length eyes, predicted outcomes differed significantly from measured postsurgical values for Holladay 1, Holladay 2, and Hoffer Q (P < 0.05) but not SRK/T or Haigis or Barrett Universal II .

Conclusions: The formulas had comparable predictive accuracy in silicone oil-tamponaded eyes with normal axial length, but Haigis or SRK/T or Barrett Universal II may be preferable in long axial length eyes.

Trial registration: ChiCTR1900023215.