B-mode ocular ultrasound findings in adults with refractive errors at Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria

Abstract

Objective: To ascertain the relationship between B-mode ocular ultrasound findings and standard autorefraction results of participants with refractive errors, with the aim of using B-mode ultrasound as a complementary technique to determine the refractive state of the eye. Materials and Methods: The study population consisted of 255 adult patients with refractive errors, aged 18–40 years. The ocular dimensions were measured using MINDRAY DC-7.0 real-time ultrasound machine with frequency probe of 5 and 7–12 MHz. The ocular shapes and other biometric measurements were then correlated with the results of the standard autorefraction. Results: The sensitivity for prolate ocular shape corresponding with myopia/astigmatism was 88.6%, whereas that of oblate ocular shape corresponding with hyperopia/astigmatism was 87.4%. The Pearson’s correlation coefficient between right axial length and right spherical equivalent was negatively strong at −0.79 (P < 0.001). In addition, the Pearson’s correlation coefficient was negatively strong at −0.76 (P < 0.001) between left axial length and left spherical equivalent. Conclusion: Real-time B-mode ocular ultrasound has a high sensitivity in determining ocular shape, which corresponded well with the refractive state of the participants’ eyes. Axial length (AL) was found to correlate strongly with spherical equivalent, and, thus, a regression equation can be used to predict the spherical equivalent from the AL measurements.