Comparison of the clinical effects of carbomer-based lipid-containing gel and hydroxypropyl-guar gel artificial tear formulations in patients with dry eye syndrome: a 4-week, prospective, open-label, randomized, parallel-group, noninferiority study.

BACKGROUND

Most marketed artificial tears are substitutes for the aqueous layers of the tear film; therefore, frequent instillation of artificial tears is necessary. Newer gel-, cellulose-, and mineral oil-based formulations have been designed to overcome the disadvantages of current aqueous tear substitutes by offering prolonged retention times.

OBJECTIVES

The aim of this study was to compare the efficacy, safety, and local tolerance of artificial tears containing carbomer-based lipids or hydroxypropyl (HP)-guar gel in patients with dry eye syndrome.

METHODS

A 4-week, prospective, randomized, parallel-group, comparative, noninferiority study was conducted at the Taipei Medical University Hospital (Taipei, Taiwan) in patients with dry eye syndrome who were randomly assigned to 1 of 2 treatment groups: the carbomer-based lipid-containing (CBLC) gel group and the HP-guar gel group. The primary end point was global assessment of study treatment by the patients at weeks 2 and 4. All patients met the diagnostic criteria of impaired tear function and ocular surface abnormalities. Outcomes measured at baseline and 2 and 4 weeks included Schirmer's test values, tear breakup time (TBUT), and a patient subjective assessment of symptoms. Safety and tolerability were assessed by clinically significant changes in terms of incidence of adverse events and conducted by unmasked investigators.

RESULTS

A total of 30 Taiwanese patients with dry eye syndrome were included and randomly assigned to the 2 treatment groups: the mean (SD) age was 40.37 (14.96) years in the CBLC gel group and 49.49 (12.20) years in the HP-guar gel group. At baseline, the mean (SD) Schirmer's test value was 4.53 (2.28) mm in the right eye and 5.13 (2.42) mm in the left eye in the CBLC gel group; 4.40 (2.16) mm in the right eye and 4.20 (1.78) mm in the left eye for the HP-guar gel group. The mean (SD) for both eyes was 4.83 (2.36) mm in the CBLC gel group and 4.30 (2.08) mm in the HP-guar gel group. There was no statistically significant difference between Schirmer's scores at baseline. Patients in both treatment groups experienced an improvement from baseline in symptoms and signs, Schirmer's test value, and TBUT at 2 and 4 weeks after treatment. The Schirmer's test score increased to a mean of 8.20 (4.49) mm in the right eye and 9.33 (4.94) mm in the left eye in the CBLC gel group after 2 weeks, and increased to 10.07 (5.56) mm in the right eye and 10.86 (5.58) mm in the left eye after 4 weeks. The increases in Schirmer's test score and TBUT were also observed in the HP-guar gel group. The Schirmer's test score increased to 5.13 (2.18) mm in the right eye and 5.60 (2.74) mm in the left eye after 2 weeks, and increased to 6.93 (3.37) mm in the right eye and 6.53 (3.16) mm in the left eye after 4 weeks. The increase in Schirmer's test values in both eyes was significantly greater at 2 and 4 weeks in the CBLC gel group than that in the HP-guar gel artificial tear group (all, P < 0.05). Subjective patient assessment was better with the CBLC group (excellent and good reported by 26.6% and 73.4%, respectively, of the CBLC gel group vs 13.4% and 33.4% of the HP-guar gel group at 4 weeks; both, P = 0.004).

CONCLUSIONS

Both artificial tear formulations were effective in relieving dry eye syndrome in these patients. The tolerance of CBLC gel artificial tears was comparable to that of HP-guar gel artificial tears.