Comparison of carboxymethylcellulose vs. hydroxypropyl methylcellulose as a gonioscopic fluid

Hydroxypropyl methylcellulose (HPMC), a popular gonioscopic solution, can cause discomfort and blurred vision. These side effects have been attributed to the preservative benzalkonium chloride (BAK). Carboxymethylcellulose (CMC), an unpreserved, viscous solution, might well provide adequate patient comfort and cushioning during gonioscopy without producing blur or irritation. The effects of CMC and HPMC during gonioscopy were evaluated in 55 human subjects. Corneal staining, comfort, subjective vision, and measured visual acuity (VA) were assessed. In comparison with HPMC, CMC effected less corneal staining, greater comfort, and better vision after the procedure, CMC proved to be a viable and superior alternative to HPMC as a gonioscopic solution.