Abstract
Purpose :
Optical biometry is considered the gold standard method for IOL calculation due to its high accuracy, non-contact nature, however, it can be limited by the presence of media opacities. The study aimed to evaluate the effectiveness of three different optical biometers in cataractous eyes.
Methods :
Adults participants referred for optical biometry and IOL calculation cataract surgery. Presenting distance visual acuity (VA) in logMAR chart was measured and anterior segment eye was assessed in slit-lamp followed by fundus examination. Cataract classification was based on the Lens Opacities Cataract System (LOCS III). Axial length (AL), average corneal refractive power (K) and anterior chamber depth (ACD) measurements were acquired from three different optical biometry devices (Lenstar LS 900, IOLMaster 500 and AL-Scan). The acquisition rates (effectiveness) were determinated as the success in the AL measurement. Inter-biometry agreement for axial length (AL), corneal refractive power (K) and the anterior chamber depth (ACD) was qualified by the intraclass correlation coefficient (ICC) and the association of the acquisition failure with the type and severity cataract and the VA was also investigated by multivariate regression.
Results :
Eighty participants (58.8% female) aged 42 to 92 years (mean=69.61±9.52, median=69) were included. Mean VA of cataractous eyes (n=140) was 0.93±1.1logMAR. The effectiveness was 91.43% for both Lenstar and IOLMaster, and 92.14% for AL-Scan. Good agreement among the three devices for AL, K and ACD measurements was found with ICC=0.990 (95% CI:0.986-0.993), ICC=0.995 (95% CI: 0.993-0.996) and ICC=0.954 (95% CI: 0.919-0.972), respectively. In multivariate regression, the acquisition failure in the Lenstar (p=0.027) and the AL-Scan (p=0.034) was associated with increased severity of cortical cataract. Decreased VA contributed to the acquisition failure in AL-Scan in cases of nuclear (p=0.005) or posterior subcapsular cataract (p=0.009). The IOLMaster failures was not significantly associated with type/severity of cataract and VA.
Conclusions :
A high effectiveness for Lenstar LS 900, IOLMaster 500 and AL-Scan was found in axial length measurement in different types and severity of cataracts, as well as excellent agreement among them of biometrical parameters obtained. Acquisition rates of Lenstar and AL-Scan can be affected by cortical cataracts severity and reduced visual acuity.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.