Biometric Changes After Trabeculectomy with Contact and Non-contact Biometry

Area of Science:

• Ophthalmology
• Biometry
• Glaucoma Surgery

Background:

• Trabeculectomy is a common glaucoma surgery.
• Accurate biometric measurements are essential for post-operative management and future refractive predictions.
• Mitomycin-C is frequently used to augment trabeculectomy outcomes.

Purpose of the Study:

• To compare changes in axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) after mitomycin-C-augmented trabeculectomy using contact ultrasound and noncontact optical biometry.
• To determine the preferable biometry method for post-trabeculectomy assessments.

Main Methods:

• Prospective study of 31 glaucoma patients undergoing trabeculectomy.
• Biometric parameters (AL, ACD, LT) measured pre-operatively and at 3 and 6 months post-operatively.
• Comparison between contact ultrasound biometry (UD-6000) and noncontact optical biometry (Lenstar).

Main Results:

• Both methods showed significant decreases in AL and ACD post-surgery.
• Noncontact optical biometry yielded significantly lower AL reduction compared to ultrasound.
• No significant difference in ACD changes between the two methods.
• A significant increase in LT was observed with noncontact biometry at follow-up.

Conclusions:

• Both contact and noncontact biometry detect significant AL and ACD decreases after trabeculectomy.
• Noncontact optical biometry is recommended for AL measurement due to lower reported reduction, aiding intraocular lens power calculations.
• Increased LT measured by noncontact biometry may signal early cataract progression post-trabeculectomy.