Evaluation of ocular surface status in patients with glaucoma treated with preservative or preservative-free prostaglandin analogs

Abstract

Background Glaucoma is one of the eye diseases that require chronic treatment. Prostaglandin derivatives are popular for treating glaucoma. Most prostaglandin drops contain benzalkonium, which contains the contraceptive pill. Aim Comparing the ocular surface changes in patients with primary open-angle glaucoma treated with preservative-free versus preserved prostaglandin analogs (PGAs). Patients and methods This prospective study was carried out on 40 eyes of 40 patients with newly diagnosed primary open-angle glaucoma and randomly divided into two groups that received PGAs: group A (20 eyes) received preserved PGA (latanoprost 0.005%), and group B (20 eyes) received preservative-free PGA (tafluprost 0.0015%). After 3 months of treatment, the ocular surface status in every patient was evaluated by Schirmer 1 test, tear film break-up time, fluorescein corneal staining, impression cytology, and Ocular Surface Disease Index questionnaire. Results Schirmer 1 test showed that 90% of patients in group B had normal values compared with 40% in group A (P=0.008). Tear film break-up time showed that 90% of patients in group B had normal values compared with 35% in group A (P=0.004). Regarding fluorescein corneal staining, 100% of the patients in group B had normal values compared with 60% in group A (P=0.007). Impression cytology grading was significantly better in group B (P<0.001). According to the Ocular Surface Disease Index score, patients on tafluprost treatment reported better drug tolerability (P=0.041). Conclusion Patients with glaucoma treated with preservative-free PGA have fewer ocular surface adverse effects, which may increase the tolerability of topical glaucoma medications.