A pre-application drop containing carboxymethylcellulose can reduce multipurpose solution-induced corneal staining

Area of Science:

• Ophthalmology
• Corneal Physiology
• Contact Lens Technology

Background:

• Polyhexanide-based multipurpose solutions (MPSs) used for contact lens disinfection are associated with low-grade corneal staining.
• In vitro studies indicate carboxymethylcellulose (CMC) may neutralize polyhexanides, potentially mitigating this side effect.

Purpose of the Study:

• To investigate if a pre-application drop of CMC can reduce in vivo corneal staining caused by polyhexanide MPSs.

Main Methods:

• A randomized, cross-over study involving 30 soft contact lens wearers.
• Subjects used a Group II lens daily for 4 weeks, disinfecting with a polyaminopropyl biguanide MPS.
• A lens lubricant containing either CMC or povidone was applied before each wear period.

Main Results:

• Corneal staining scores increased over 4 weeks for both CMC and povidone groups, indicating worsening with wear.
• The increase in staining was significantly less with CMC (4.9) compared to povidone (7.1).
• No significant difference in symptom scores was observed between the two lubricant groups.

Conclusions:

• A CMC-containing pre-application drop effectively reduces corneal staining associated with polyhexanide MPS disinfection.
• This supports the proposed mechanism of CMC neutralizing cationic disinfectants.
• CMC drops may offer a clinical strategy to minimize contact lens-related corneal staining.