Study Purpose: To evaluate the level of agreement between the Acuvera Capture application and traditional paper-based methods for recording Best Corrected Visual Acuity (BCVA) in ophthalmic clinical trials. The study aims to determine whether the electronic capture system provides equivalent or improved accuracy, consistency, and error reduction compared with paper-based recording, thereby supporting its potential adoption as a reliable method for BCVA data collection in clinical research.

Background and Rationale: Best Corrected Visual Acuity (BCVA) is the most widely accepted and clinically meaningful functional endpoint in ophthalmic clinical trials. It is routinely used to assess treatment efficacy, disease progression, and visual function across a broad spectrum of ocular diseases, including age-related macular degeneration (AMD), diabetic retinopathy, and inherited retinal diseases. Regulatory authorities such as the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) recognize BCVA as a primary endpoint in pivotal trials, and therapeutic approvals often hinge on statistically and clinically significant changes in BCVA outcomes (1-3).

Despite this critical role, BCVA data collection in clinical trials remains vulnerable when recorded on traditional paper forms. Common challenges include:

Calculation errors: Manual determination of the total number of letters correctly identified during BCVA testing is prone to human error, particularly when partial lines are read or when examiners must manually apply line-by-line scoring rules. Miscounting or incorrect summation of letter scores can result in inaccurate BCVA values and distort subsequent data analyses. These errors are inherent to paper-based recording processes and highlight the need for standardized, automated systems capable of performing real-time calculations to ensure data accuracy and consistency across study sites (1,2,3).

Transcription Errors: Manual transfer of BCVA scores from testing charts to case report forms can result in numerical misentries and calculation mistakes (4).

Omission and Misrecording: Missed data points, illegible handwriting, or recording the wrong line/letter score can compromise data integrity (5).

Protocol Deviations: Variations in testing procedures (e.g., incorrect testing distance, inappropriate prompting, or examiner bias) are not always detected in real time, introducing variability and bias (6).

Delayed Error Detection: Errors are often identified only retrospectively, during central reading or data monitoring, causing delays in data cleaning, increased trial costs, and, in some cases, regulatory queries (7).

Digital capture solutions such as Acuvera Capture address these limitations by embedding real-time quality control at the point of care. The application incorporates automated error detection, warning systems for protocol deviations, and standardized workflow guidance, ensuring higher data fidelity. By minimizing calculation, transcription and protocol errors, Acuvera Capture has the potential to strengthen data reliability, streamline trial conduct, and increase regulatory confidence in BCVA endpoints.

Given that BCVA is the most critical functional endpoint in ophthalmic clinical trials, even small improvements in accuracy and reproducibility can substantially impact study outcomes, regulatory acceptability, and sponsor credibility. This study will directly compare Acuvera Capture against paper-based recording to validate data agreement and assess error rates, efficiency, and usability, thereby generating essential evidence to support digital transformation of BCVA data collection.

90 adult participants (≈180 eyes) with the following BCVA levels, will be included:

• 30 participants (33%) in the normal/near-normal BCVA range (≤0.3 logMAR ≥70 letters); ≈20/40 or better);
• 30 participants (33%) with mid-range BCVA (0.4-0.9 logMAR (36-69 letters); 20/50 to 20/200)
• 30 participants (33%) with low vision BCVA (≥ 1.0 logMAR (≤35 letters); worse than 20/200) including off-chart acuities using protocol low-vision procedures).

Inclusion Criteria:

• Adults ≥18 years old
• Able and willing to provide written informed consent
• Capable of performing BCVA testing procedures according to study requirements
• All BCVA ranges are eligible, including off-chart acuities (e.g., count fingers, hand motion, light perception) irrespective of the presence or absence of ocular disease.

Exclusion Criteria:

• Any condition preventing reliable completion of BCVA testing (e.g., severe cognitive impairment, language barriers)
• Inability or unwillingness to comply with study requirements
• Non-ophthalmic condition that precludes safe or reliable testing (e.g., immediate post-operative systemic status preventing cooperation).
• Any circumstance that, in the investigator's opinion, makes the eye/participant unsuitable for accurate BCVA testing or for completing both data-capture methods during the same visit.

Number of Sites: 2 ophthalmic clinical research centers Portugal)

Number of Countries: Portugal

Number of Visits: One study visit per participant

Duration: 2 months

Participants will undergo BCVA testing at a single visit using both paper-based recording and electronic capture with Acuvera Capture. Testing order will be randomized to minimize bias. Paper data will be inserted by the examiners or study coordinator into the study eCRF. Electronic capture data will be exported directly from the app.

Overall, a total of 90 participants, evenly distributed across three BCVA strata (normal/near-normal, mid-range, and low vision; approximately 30 participants per group), remains appropriate for this study's aims: it ensures representation across the acuity spectrum while providing decision-grade precision for concordance (ICC/Bland-Altman), informative bounds on error rates, and pragmatic sensitivity to workflow time differences, without over-scaling an observational validation.