Comparison of two methods for location of the ciliary body before glaucoma treatment using High Intensity Focused Ultrasound (HIFU)

• Published in: Acta ophthalmologica (Oxford, England) Vol. 92; no. s253
• Main Authors: APTEL, F, ROULAND, J, CHAVEROT, D, DUPUY, C, COPPIN, J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2014; Wiley Subscription Services, Inc
• Subjects: Ophthalmology
• ISSN: 1755-375X; 1755-3768
• DOI: 10.1111/j.1755-3768.2014.T043.x

Purpose To evaluate the ability of the white‐to‐white (WTW) and axial length (AL) measurements to determine the location of the ciliary body before High Intensity Focused Ultrasound (HIFU) glaucoma treatment. Methods 189 eyes (104 phakic, 85 pseudophakic) of 161 patients were included. WTW and AL measurements were measured with the IOLMaster. The HIFU size probe selection was done based using ultrasound biomicroscopy (UBM) and a computer assisted overlay drawing method performed by the manufacturer of the HIFU device. Three probe models with different ring diameters (11, 12 and 13mm) are available for HIFU treatment. Eyes were divided into 3 groups: “11” (n=11), “12” (n=83) and “13” (n=95) corresponding to the size of the probe recommended based on UBM images. The agreement between the group and the WTW and AL were evaluated. Results For groups "11", “12” and “13”, mean WTW and AL measurements were respectively 11.44 ± 0.11 mm and 22.04 ± 0.28 mm, 11.84 ± 0.04 mm and 23.22 ± 0.20 mm, and 12.36 ± 0.06 mm and 25.43 ± 0.3 mm. Mann&Whitney and ANOVA tests showed a significant difference between the 3 groups (p<.05). By placing all the data in a coordinate system WTW‐AL, we can distinguish 3 areas (11, 12 and 13) allowing to choose the diameter with a 93% agreement with the UBM‐based determination. Conclusion It seems possible to determine the probe model with a nomogram based on easily measurable ocular parameters.