Overview
EN ISO 12866:1999 - Ophthalmic instruments - Perimeters (ISO 12866:1999) specifies requirements and test methods for instruments that assess differential light sensitivity across the visual field by subjective detection of test stimuli on a defined background. It is a type‑testing standard for perimeters (projection and fixed‑location) and defines terms, performance tolerances, stimulus specifications (including Goldmann stimulus sets), and required documentation. The standard is intended for the instrument performance and does not prescribe clinical testing methodologies.
Key topics and technical requirements
- Scope and definitions: precise definitions for visual field concepts (central, peripheral, monocular/binocular), perimeter types (projection, fixed‑location, kinetic, static), and photometric terms (background luminance, stimulus luminance, differential luminance, threshold).
- Performance tolerances: specified tolerances for background luminance, contrast (DL/LB), stimulus location, size (converted to solid angle), shape, and duration (see Table 1 in the standard).
- Stimulus specifications: Goldmann test stimulus sizes and differential luminances are referenced (Annex A) and stimulus coordinate systems are provided (Annex B).
- Minimum coverage: required minimum eccentricities and minimum total potential stimulus locations for central, midperipheral and full‑field perimeters (Tables 2 and 3).
- Kinetic vs static perimeters: requirements for smooth and continuous stimulus movement and specification of speed/characteristics for kinetic perimeters; temporal presentation, stimulus patterns and coordinate referencing for static perimeters.
- Test methods and type tests: standardized procedures for measuring background luminance, stimulus luminance, test stimulus location, size, shape and duration (clause 5). Type testing for projection and fixed‑location perimeters requires repeated measurements at defined locations (Table 4).
- Device features and documentation: requirements for fixation monitoring, optical correction provision, head positioning, ability to quantify per‑location results, and contents of test records.
Applications and users
- Manufacturers of ophthalmic perimeters - to design, validate and document device performance to internationally accepted tolerances.
- Test laboratories and conformity assessors - to perform type testing, calibration and verification of perimeters against ISO 12866 requirements.
- Regulatory and quality teams - for device submissions, technical files and compliance with harmonized ophthalmic instrument standards.
- Clinical engineers and hospital biomedical departments - for acceptance testing, maintenance and performance verification of perimeter equipment (note: the standard does not define clinical test protocols).
Related standards
- ISO 15004:1997 - Ophthalmic instruments - fundamental requirements and test methods (ISO 12866 takes precedence where differences exist).
- IEC 60601‑1 / IEC 60601‑1‑1 - Medical electrical equipment safety standards referenced for general safety and system requirements.
Keywords: ophthalmic instruments, perimeters, ISO 12866, perimetry, visual field, Goldmann stimulus, background luminance, differential light sensitivity, static perimeter, kinetic perimeter, type testing, device calibration.
