Офтальмохирургия (Dec 2015)
POSTERIOR CHAMBER PHAKIC IOL SIZING. PART I. A NEW ALGORITHM OF SULCUS CILIARIS DIAMETER ASSESSMENT USING ANTERIOR SEGMENT OPTICAL COHERENCE TOMOGRAPHY
Abstract
Purpose. To study the effectiveness of a new algorithm in measurement of sulcus ciliaris diameter by the method of anterior segment optical coherence tomography (AS-OCT). Material and methods. Thirty two patients (32 eyes) with high myopia (age range: 19 to 50 years) underwent the comprehensive examination. Mean spherical equivalent (SE) in the study group averaged -13.12 D (range: -6.25 to -21.50 D). Mean axial length was 27.97±1.94mm (range: 24.26 to 31.64mm). Initially we analyzed in details the anatomy of anterior segment of each eye and measured precisely horizontal sulcus ciliaris diameter by the method of ultrasound bio-microscopy (UBM). After that the same parameter was assessed using the new AS-OCT measurement algorithm. Finally we compared UBM measurement results with the AS-OCT and evaluated intra-session intra- and inter-operator repeatability for the obtained AS-OCT data. Results. The UBM analysis of the anterior segment anatomy showed a correspondence of the peripheral iris pigment layer edge (IPE) to the lateral border of the sulcus ciliaris and gave proof of possibility of sulcus ciliaris diameter assessment using the AS-OCT. Mean sulcus ciliaris diameter values with UBM and AS-OCT were 12.35±0.47mm (range: 11.39 to 13.25mm) and 12.36±0.52mm (range: 11.40 to 13.35mm) respectively (P>0.05). Intra-session intra- and inter-operator repeatability did not exceed 0.17mm and 0.13mm respectively, while intra-individual coefficients of variation did not exceed 0.49% and 0.33% respectively. Conclusion. The new AS-OCT algorithm can be effectively used to assess sulcus ciliaris diameter with a high level of precision and repeatability. Application of this algorithm in posterior chamber phakic IOL sizing will be discussed in the next report.
