[Bruch's Membrane Opening in OCT in Correlation with Corneal Correction - a Pilot Study]

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Diagnostics

Background:

• Optical coherence tomography (OCT) is used clinically since 2014 to measure Bruch membrane opening (BMO) and Bruch membrane opening-minimum rim width (BMO-MRW).
• Corneal compensation, using the mean K-value, is applied to OCT measurements to correct for astigmatism and corneal power variations.

Purpose of the Study:

• To evaluate the impact of corneal compensation adjustments on BMO and BMO-MRW measurements.
• To determine the clinical relevance of corneal compensation in OCT-based retinal diagnostics.

Main Methods:

• Five healthy subjects' right eyes underwent five repeated BMO-MRW and BMO measurements using Heidelberg Spectralis OCT.
• Corneal compensation was systematically varied across measurements (7.1, 7.4, 7.7, 8.0, 8.3 mm K-values).

Main Results:

• BMO-MRW measurements showed minimal changes (0.85-1.97%) per 0.3 mm K-value difference, indicating low sensitivity to corneal compensation.
• BMO measurements exhibited greater sensitivity, with a mean change of 7.71% for every 0.3 mm change in corneal compensation.
• A nearly linear dependence of measurements on corneal compensation values was observed, with intraindividual variability.

Conclusions:

• Corneal compensation demonstrates low clinical relevance for BMO-MRW measurements in routine OCT assessments.
• BMO measurements are significantly influenced by corneal compensation, necessitating accurate application.
• While low impact for BMO-MRW, precise corneal compensation is recommended for initial and follow-up BMO measurements to avoid misinterpretation.