Predictability of combined cataract surgery and trabeculectomy using Barrett Universal Ⅱ formula

Area of Science:

• Ophthalmology
• Biomedical Engineering

Background:

• Cataract surgery with trabeculectomy presents unique challenges for intraocular lens (IOL) power calculation.
• Accurate IOL power calculation is crucial for achieving desired refractive outcomes post-surgery.

Purpose of the Study:

• To compare the predictability of the Barrett Universal II and SRK/T formulas for IOL power calculation.
• To evaluate the refractive outcomes in eyes undergoing combined cataract surgery and trabeculectomy.

Main Methods:

• Retrospective review of 56 eyes undergoing combined cataract surgery and trabeculectomy.
• IOL power calculations performed using Barrett Universal II and SRK/T formulas.
• Comparison of prediction error, absolute error, and refractive outcomes at 3 months postoperatively.

Main Results:

• The SRK/T formula resulted in significantly more myopic prediction errors compared to the Barrett Universal II formula.
• The Barrett Universal II formula demonstrated significantly smaller absolute errors.
• Prediction errors with the SRK/T formula correlated with axial length and keratometric readings, unlike the Barrett Universal II formula.

Conclusions:

• The Barrett Universal II formula offers superior predictability for IOL power calculation in eyes undergoing combined cataract surgery and trabeculectomy.
• The Barrett Universal II formula is less influenced by axial length and corneal shape, leading to improved refractive accuracy.
• The Barrett Universal II formula is recommended for clinical use to enhance refractive outcomes in these complex cases.