AIM: To evaluate and compare the clinical performance of 5 kinds of polyhexamethylene biguanide(PHMB)based multi-purpose solutions(MPS)manufactured in China when used with a commercially available silicone hydrogel contact lens in terms of solution-induced corneal staining(SICS), ocular response(corneal staining and ocular hyperemia), corneal infiltrative events(CIE)and ocular comfort.

METHODS: This was a prospective, open label, randomized, parallel group clinical trial. Totally 162 participants who were at least 18y old were enrolled and randomized into 5 groups of PHMB-based MPS made in China: Complete^® MPS, Hydron^® Aqua-shining moist, Baoshining^TM, Weicon^® Fresh, Weicon^® 2000 MPS(abbreviated as C, H, B, W, and W2). All participants wore balafilcon A contact lenses with monthly disposal(Bausch & Lomb Purevision^®)in conjunction with the designated MPS on a daily wear for 3mo. Clinical visits were at baseline, 2wk, 1 and 3mo. SICS and CIE were reported as first event incidence per 100 Px-months. Ocular response was graded on 0-4 scale in 0.5 steps(0=none, 4=severe)and ocular comfort was assessed via a numeric rating scale(1-10 in 1-point steps, 1=poor, 10=excellent). Ocular comfort and ocular response variables were analysed using linear mixed model. CIE and SICS were analysed using Fisher's exact test and logistic regression.

RESULTS: There were 36(22%)Pxs who dropped out. SICS incidence for each MPS were: H(26.3%),B(20.8%), W(19.4%), W2(13.4%), C(12.8%). The SICS rate of H was significantly different to W2(P = 0.012)and C(P = 0.005). There were no significant differences in ocular response, CIE incidence and ocular comfort between different MPSs(P>0.05). Pxs with SICS had significantly lower comfort during the day and at the end of than those who did not have SICS.

CONCLUSION: Differences in SICS incidence were found between MPSs but not for CIE incidence, ocular response or ocular comfort. SICS in PHMB-based MPS was found to be associated with ocular discomfort.