Refractive Results Using a New Optical Biometry Device: Comparison With Ultrasound Biometry Data

Lenstar LS900 vs EchoScan US-800: comparison between optical and ultrasound biometry with and without contact lenses and its relationship with other biometric parameters

BACKGROUND

Due to the increasing use of contact lenses (CL) and the interest in ocular and body size relationships, this study aimed to compare measurements from two biometers (contact ultrasonic EchoScan US-800 and non-contact optical Lenstar LS900) with and without CL and to explore the relationship between ocular and body biometric parameters.

DESIGN AND METHODS

This cross-sectional study measured ocular biometry using two biometers along with their body height and right foot length in 50 participants. Differences between biometry data from the two devices were compared and correlations between ocular and body biometric values were analyzed.

RESULTS

All parameters showed interbiometric differences (p ≤ 0.030), except crystalline lens thickness during CL wear (p = 0.159). Comparing measurements with and without CL, differences were observed in axial length (p < 0.001), vitreous length measured by optical biometer (p = 0.016), and anterior chamber depth by ultrasonic biometer (p < 0.016). Lens thickness remained unaffected (p ≥ 0.190). Body height and foot length were correlated with anterior chamber depth, vitreous length, and axial length (p ≤ 0.019, r ≥ 0.330). Most biometric parameters were correlated among them using both devices (p ≤ 0.037, r ≥ 0.296).

CONCLUSIONS

These biometers are not interchangeable and CL affects measurements. Body height and foot length correlate with ocular dimensions, and most ocular biometric values correlate positively.

Effect of Cycloplegia on Optical Biometry in Pediatric Eyes

PURPOSE

To study the effect of cycloplegia on optical biometry parameters in pediatric eyes using the Lenstar LS 900 (Haag-Streit, Koeniz, Switzerland).

METHODS

In this observational and comparative study, 56 normal eyes and 20 cataractous eyes in children between 5 and 15 years of age were included. Measurements were taken before and after cycloplegia using 2% homatropine drops. Parameters studied were axial length, central corneal thickness, keratometry, anterior chamber depth, and lens thickness. The Wilcoxon test was used to compare the effects of cycloplegia on all parameters.

RESULTS

Cycloplegia resulted in a statistically significant decrease in axial length (P < .05), central corneal thickness (P < .05), and lens thickness (P < .001) and an increase in the anterior chamber depth (P < .001) in normal eyes. In the cataract group, cycloplegia resulted in an increase in anterior chamber depth (P < .001) and decrease in lens thickness (P < .001).

CONCLUSIONS

Biometry measurements have to be carefully interpreted in pediatric eyes where cycloplegia is an important part of the examination. [J Pediatr Ophthalmol Strabismus. 2018;55(4):260-265.].