Overview
ISO 9394:2012 - "Ophthalmic optics - Contact lenses and contact lens care products - Determination of biocompatibility by ocular study with rabbit eyes" - specifies an in vivo method to assess ocular biocompatibility and ocular irritation produced by contact lenses and contact-lens care products using rabbit eyes. The standard describes study design, animal care, test specimen preparation, observation schedules, scoring systems and post‑mortem histology to evaluate tissue response and safety.
Key topics and technical requirements
- Scope: In vivo ocular irritation testing of novel contact lens materials and care products; results are specific to rabbit-eye model and require cautious human extrapolation.
- Animals & husbandry: Use New Zealand white or equivalent albino rabbits (>2.5 kg), acclimatized, individually housed, minimal restraint; follow animal welfare per ISO 10993-2.
- Sample size & controls: Minimum three rabbits (six recommended); contra-lateral eye or separate control group; positive controls are not used.
- Test duration & schedule: Daily lens wear days 1–21 (typically 7–8 h/day), final removal on day 22 (4–8 h). Clinical examinations scheduled on days 1–7, 9–14, 16–21 (Draize scoring) and slit-lamp exams with fluorescein on days 8, 15 and 22 (McDonald‑Shadduck scoring).
- Scoring & endpoints: Use Draize and McDonald‑Shadduck systems (normative annexes) for ocular lesion and slit-lamp scoring. Record behaviour, lens expulsions, lens condition and body weight (pre-test and day 22).
- Histology: After euthanasia on day 22, excise eyes/adnexa, fix, embed, section and stain cornea, conjunctiva, iris and lens for microscopic evaluation.
- Materials & apparatus: Sodium fluorescein, manufacturer‑recommended lenses and care products, slit lamp microscope, magnifier (≥6×), and an accurate balance.
- Quality & compliance: Studies should follow GLP, ISO/IEC 17025 where applicable, and ISO 10993‑1/10 guidance for biological evaluation and irritation testing.
Applications and who uses it
- Contact lens and contact lens solution manufacturers validating ocular safety and biocompatibility during product development and regulatory submissions.
- Contract testing laboratories performing standardized ocular irritation tests under GLP.
- Regulatory reviewers and quality/medical device teams evaluating preclinical ocular safety data.
- R&D scientists comparing materials (hydrogel vs silicone hydrogel) and assessing lens-care product compatibility.
Related standards
ISO 9394 provides a structured, recognized protocol for in vivo ocular biocompatibility testing of contact lenses and care products, enabling reproducible safety assessment and supporting regulatory compliance.