Comparison of Two Biometers in Dense Cataracts

Overview

This single-center, ambispective, observational study evaluates axial length acquisition in eyes with dense cataracts using the ARGOS swept-source optical coherence tomography biometer compared with the IOLMaster 700. Eligible subjects are pseudophakic adults who previously underwent complex cataract surgery because of poor visualization or poor red reflex from dense lens opacity and who had pre-operative biometry performed with both devices, with or without manual immersion A-scan ultrasonography. Enrolled subjects return for postoperative repeat biometry to confirm pre-operative measurements and to assess whether availability of an ARGOS axial length measurement may reduce the need for manual ultrasound A-scans in similar dense cataract cases. The planned sample size justification estimated that 61 patients were needed for statistical power, while 68 were originally targeted to allow for attrition in the prospective portion.

Cataract surgery is the most commonly performed surgical procedure in the United States. Accurate axial length measurement is critical for intraocular lens power selection, but optical biometry can be challenging in eyes with dense cataracts because of poor media penetration and limited signal acquisition. When optical axial length measurement cannot be obtained, manual immersion A-scan ultrasonography is often required, which adds workflow complexity, technician time, and patient time. This study was designed to evaluate the performance of the ARGOS swept-source optical coherence tomography biometer in eyes with dense cataracts and to compare its axial length acquisition capability with that of the IOLMaster 700. The study also evaluates whether use of ARGOS, including enhanced retina visualization mode when needed, may reduce reliance on manual ultrasound biometry in this setting. This is a single-center, ambispective, non-interventional observational study. The retrospective component involves review of prior cataract surgery cases in which pre-operative biometry had been performed with both the ARGOS and the IOLMaster 700 in eyes with dense cataracts associated with poor visualization or poor red reflex. The prospective component consists of a postoperative study visit in enrolled subjects for repeat biometry, allowing comparison of postoperative measurements with historical pre-operative values and assessment of whether successful ARGOS measurement could have reduced the need for confirmatory ultrasound testing. The overall purpose of the study is to better characterize the utility of ARGOS biometry in dense cataracts and to assess its potential clinical value in reducing the need for manual A-scan ultrasonography in routine practice.