First Impression of Central 3.0 mm Retinal B-Scan Captured With Optical Biometer Prototype Based on Full-Eye-Length SS-OCT Scan Biometry
Purpose
To subjectively assess scan quality of retinal layers and pathology detection captured during routine optical biometry measurements with a new full-eye-length SS-OCT-scan biometer (IOL Master 700).
Methods
As part of a full-eye length OCT-scan protocol to measure biometrical parameters for IOL power calculation, central horizontal 3 mm retinal B-scans were taken for a range of retinal pathologies using a full-eye-length SS-OCT-scan biometer prototype IOLMaster 700 (Carl Zeiss Meditec AG). Pathologies were diagnosed based on slit-lamp examination and Fourier domain posterior segment OCT. A total of 23 patients participated in the study. Pathological characteristics included macular pucker, macular hole, macular scarring, macular oedema and central RPE detachment as well as characteristics associated with dry ARMD.
Results
Compared with resolution of retinal B-scans that are captured with retinal high definition OCTs, resolution of the 3 mm retinal B-scan of full-eye-length SS-OCT-scan biometry was low. However, advanced pathological characteristics occurring within the horizontal central 3 mm zone of the retina such as macular hole, macular pucker, macular oedema, significant RPE detachments or large drusen were clearly discernible. Pucker related high reflectivity at the ILM – vitreous body intersection was also visible. It is suspected that pucker related high reflectivity can cause unreliable ILM/RPE detection in A-scan biometry. Subtle characteristics of dry ARMD (e.g. small drusen) were not discernible.
Conclusion
Foveal retinal pathologies highlighted during pre-exam routine biometrical measurements using full-eye-length SS-OCT-scan biometry could provide useful information for subsequent patient examination and further treatment planning prior to or during cataract surgery. Furthermore, retinal layer detection of the central 3 mm B-scan of full-eye-length SS-OCT-scan biometry could serve as plausibility check for axial length measurements in standard and complicated cataract cases.