Purpose: To evaluate the effects of a mid-viscosity mucomimetic lubricant eye drop containing hydroxypropyl guar (HPG) as a gelling agent on computerized perimetry FASTPAC test results of primary open-angle glaucoma (POAG) patients with trachomatous dry eye. Methods: Both eyes of 33 patients with bilateral POAG and trachomatous dry eye were included in the study. They were treated with the same antiglaucomatous eye drop and underwent computerized perimetry. Before and after the treatment with lubricant eye drop (Systane™) for 8 weeks, tear function tests (Schirmer test with topical anesthesia, fluorescein staining and tear film break-up time) and FASTPAC test with computerized perimetry were performed. Pre- and posttreatment tear functions, visual field test global indices, reliability indices, test duration and numbers of depressed points in pattern deviation plots were compared. Results: We found significant improvements in tear function tests results, in computerized perimetry FASTPAC test indices, test duration and the number of depressed points in pattern deviation plots in the posttreatment evaluations. Conclusion: This study indicates that there was a benefit of mid-viscosity lubricant eye drop containing HPG treatment on computerized perimetry FASTPAC test performance in POAG subjects with trachomatous dry eye. We assume that the positive effect of this therapy is probably due to a better tear film stability, resulting in a higher optical quality of the repaired anterior corneal surface.