Quantification of visual acuity: "Counting fingers" and "Hand movement" with the Berkeley Rudimentary Vision Test

Alba Herrero ¹, Halima Berrada ¹, Rafael I Barraquer ²

⁰Centro de Oftalmología Barraquer, Muntaner 314, Barcelona 08021, Spain.

Journal of Optometry +

|

February 9, 2025

View abstract on PubMed

Summary

The Finger Count Test (FCT) for Counting Fingers (CF) and Hand Movement (HM) correlates with visual acuity (VA) from the Berkeley Rudimentary Vision Test (BRVT) in low vision patients. Results varied significantly in patients with visual field defects.

Area Of Science

Ophthalmology
Low Vision Research
Visual Function Assessment

Background

Visual acuity (VA) assessment is crucial for low vision patients.
Traditional tests like Finger Count Test (FCT) for Counting Fingers (CF) and Hand Movement (HM) provide functional visual estimates.
Translating these estimates to standardized metrics like logMAR is essential for accurate analysis.

Purpose Of The Study

To compare visual acuity (VA) measurements from the Finger Count Test (FCT) using Counting Fingers (CF) and Hand Movement (HM) with the Berkeley Rudimentary Vision Test (BRVT).
To evaluate these tests in low vision patients with diverse ocular pathologies, including severe visual field defects.

Main Methods

Visual acuity (VA) was assessed using the Berkeley Rudimentary Vision Test (BRVT) and FCT (CF and HM) in 38 low vision patients (VA 1.40-3.50 logMAR).
Patients were classified into groups based on ocular pathology, specifically including those with severe visual field defects (central visual field constrictions or scotomas).

Main Results

In the general low vision group, median VA was 2.00 logMAR for CF and 2.60 logMAR for HM (p < 0.001).
Patients with severe visual field defects showed significant variability in BRVT VA, with considerable overlap with CF and HM results (median VA 2.10 logMAR for CF, 2.30 logMAR for HM; p = 0.824).

Conclusions

FCT (CF) VA results align with previous studies, while FCT (HM) VA was slightly worse.
These findings enable the conversion of historical CF and HM data to logMAR for robust statistical analysis.
BRVT demonstrated substantial VA variation in patients with central visual field defects.

Keywords:

Central visual field defect Finger count test Hand movement Low vision Peripheral visual field defect Visual acuity