Retrospective comparative analysis of intraocular lens calculation formulas after hyperopic refractive surgery

Area of Science:

• Ophthalmology
• Refractive Surgery
• Cataract Surgery

Background:

• Accurate intraocular lens (IOL) power calculation is crucial for successful cataract surgery.
• Previous hyperopic corneal refractive surgery (HCRS) poses challenges for standard IOL formulas.
• Evaluating IOL calculation methods in HCRS eyes without pre-operative data is essential.

Purpose of the Study:

• To compare the accuracy of different intraocular lens (IOL) calculation formulas.
• To evaluate postoperative refractive outcomes in patients with prior hyperopic corneal refractive surgery.
• To assess IOL power calculation without pre-operative refractive data.

Main Methods:

• Retrospective comparative observational study of 39 eyes from 24 patients with prior HCRS.
• Compared IOL power calculations using Holladay 2 and ASCRS Post-Refractive IOL Calculator.
• Analyzed IOL prediction error, mean error, median absolute error, and refractive outcomes within ±0.50 D and ±1.00 D.

Main Results:

• Holladay 2 formula showed a statistically significant mean arithmetic IOL prediction error (P=0.003).
• Shammas, Haigis-L, and Barret True K No History formulas had non-significant mean errors (P>0.14).
• No significant differences in median absolute error or refractive outcomes (±0.50 D, ±1.00 D) between formulas.

Conclusions:

• In HCRS eyes without pre-operative data, Holladay 2 and ASCRS calculator demonstrated comparable accuracy for IOL power calculation.
• Neither formula showed a significant advantage in predicting refractive outcomes in this specific patient group.
• Further research may explore formula adjustments for HCRS eyes.