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.

Inclusion Criteria:

• Adults aged 45 years and older
• Previously underwent complex cataract removal by phacoemulsification with a clear corneal incision in one or both eyes more than 1 month before enrollment
• Complex cataract removal was performed for poor red reflex or poor visualization due to lens density or opacification
• Pre-operative dense cataract in the study eye, defined as greater than or equal to 3+ posterior subcapsular cataract, 3+ nuclear sclerotic cataract, 3+ cortical cataract, or any combination of these
• Pre-operative biometry performed with both the ARGOS and IOLMaster 700
• Other than cataract, clear intraocular media, with no corneal opacity or vitreous hemorrhage

Exclusion Criteria:

• Pre-operative mature or white cataract in the study eye
• Any corneal abnormality, other than regular corneal astigmatism, that in the opinion of the investigator would confound study outcomes
• History of or current retinal condition, or predisposition to retinal conditions, other than posterior vitreous detachment, that in the opinion of the investigator would confound study results
• Amblyopia or strabismus in either eye
• Nystagmus or other condition that would hamper axial length capture because of poor fixation
• History of or current anterior or posterior segment inflammation of any etiology
• Any form of ocular neovascularization
• Diagnosed degenerative eye disorders
• Acute or chronic disease or illness that, in the opinion of the investigator, would confound study results, including immunocompromised state, connective tissue disease, or clinically significant atopic disease

Pseudophakic adults who previously underwent complex cataract surgery for poor red reflex or poor visualization due to dense cataract and had pre-operative biometry with both the ARGOS and IOLMaster 700.