To compare the applied signification of optical and ultrasonic biometry in observing the axial length of eyes with vitreous hemorrhage and retinal detachment.

This is a prospective clinical study. We randomly selected 57 cases (57 eyes) with vitreous hemorrhage and (or) retinal detachment from May 1, 2016 to May 31. Patients had not been performed eye surgery, also denied the history of ocular trauma and excluded other eye diseases. 25 eyes with vitreous hemorrhage, 24 eyes with retinal detachment, 8 eyes complicated with vitreous and retinal detachment hemorrhage. At 24 hours before surgery, we measured axial length using the Lenstar LS 900, immersion B-ultrasound (IB) and immersion A-ultrasound (IA). The differences between three methods were assessed with paired sample t-test.

IB and IA data was collected from all 57 eyes, there was no statistical significance between measurements of IB and IA (P>0.05). In the eyes with serious refractive medium opacity (36 eyes), the results showed no statistical significance difference between measurements of IB and IA (P>0.05). The measurements of three groups can be obtained from the rest eyes (21 eyes): significant statistical difference of the measurements between IB and Lenstar was detected [(24.057±1.441) mm vs (23.470±1.775) mm], (t=3.099, P<0.05) same results between IA and Lenstar was obtained [(23.962±1.443) mm vs (23.470±1.775) mm], difference was statistically significant (t=2.643, P<0.05). But the measurements showed no statistical significance difference between the measurements of IB and IA (P>0.05).

In the eyes with vitreous hemorrhage and (or) retinal detachment, the measurements of axial length could not be achieved or existed deviations on account of refractive medium opacity when using optical biometry. Under such circumstances, we should choose IA or IB as the optimization method to obtain measurements, in order to get much more accurate results.