Do multipurpose solutions damage porcine corneal epithelial cells?

Area of Science:

• Ophthalmology
• Cell Biology
• Toxicology

Background:

• Ophthalmic solutions, including multipurpose solutions (MPS), are widely used for contact lens care.
• Assessing the cytotoxic effects of MPS on ocular surface cells is crucial for patient safety.
• Previous methods for evaluating cytotoxicity may lack sensitivity.

Purpose of the Study:

• To compare the cytotoxic effects of commercially available MPS on porcine corneal epithelial cells.
• To evaluate the efficacy of fluorescein staining versus flow cytometry (FCM) in detecting cytotoxicity.

Main Methods:

• Porcine corneal epithelial cells were exposed to MPS containing polyquaternium-1 (MPS-A), polyaminopropyl biguanide (MPS-B), and polyhexanide (MPS-C) for varying durations.
• Cell viability and membrane integrity were assessed using Annexin V-FITC/7-AAD staining and FCM.
• Corneal fluorescein staining was performed on whole corneas immersed in MPS and controls.

Main Results:

• MPS-A demonstrated significantly higher cytotoxicity, indicated by increased 7-AAD staining (early necrosis) and Annexin V-FITC/7-AAD staining (late necrosis), compared to MPS-B, MPS-C, and controls.
• Cytotoxicity of MPS-A showed a strong positive correlation with exposure time.
• Fluorescein staining showed poor correlation with cytotoxicity and lacked sensitivity in detecting early cellular damage.

Conclusions:

• MPS, particularly MPS-A, exerts significant cytotoxic effects on porcine corneal epithelial cells.
• Fluorescein staining is an insensitive method for assessing the cytotoxic potential of ophthalmic solutions.
• Differential staining and FCM are more reliable and sensitive methods for evaluating the cytotoxicity of ophthalmic solutions.