Ocular Surface Disease in Glaucoma: Effect of Polypharmacy and Preservatives.
OBJECTIVE
To evaluate the prevalence of ocular surface disease (OSD) in glaucoma and nonglaucoma subjects using different clinical tests and to determine the effect of number of antiglaucoma medications and preservatives on OSD.


METHODS
This is a cross-sectional, case-comparison study at the Eye Clinic of the University of Malaya Medical Centre, Malaysia, between June 2012 and January 2013. Glaucoma subjects (n = 105) using topical antiglaucoma medications were compared with control subjects (n = 102) who were not on any topical medications. The presence of OSD was assessed using the tear film breakup time (TBUT) test, corneal staining, Schirmer test, and Ocular Surface Disease Index (OSDI) questionnaire grading.


RESULTS
The prevalence of OSD varied from 37 to 91% in the glaucoma group, depending on the type of clinical test. More subjects in the glaucoma group had corneal staining (63% vs. 36%, p = 0.004), abnormal Schirmer tests (39% vs. 25%, p = 0.049), and moderate OSDI symptoms (17% vs. 7%, p = 0.028). The percentage with abnormal TBUT increased with higher numbers of topical medications and was high with both benzalkonium chloride-containing and preservative-free eye drops (90% and 94%, respectively, both p < 0.001). Benzalkonium chloride was associated with a nearly three times higher odds ratio of showing abnormal OSDI.


CONCLUSIONS
Ocular surface disease is common in those using topical antiglaucoma medications. Abnormal TBUT is associated with increasing number of eye drops and benzalkonium chloride-containing eye drops, although this also occurs with the use of preservative-free eye drops.
*MSOphth Department of Ophthalmology, University of Malaya, Kuala Lumpur, Malaysia (all authors).
Norlina
N
Ramli
Gowri
G
Supramaniam
Amir
A
Samsudin
Azida
A
Juana
Mimiwati
M
Zahari
May May
MM
Choo
D000368:Aged; D000959:Antihypertensive Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001548:Benzalkonium Compounds / Q000009:adverse effects*; D003229:Conjunctival Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*; D003316:Corneal Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D005141:Eyelid Diseases / Q000139:chemically induced / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D005901:Glaucoma / Q000150:complications* / Q000188:drug therapy; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D019338:Polypharmacy; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects*; D015995:Prevalence; D011795:Surveys and Questionnaires; D013666:Tears
D000959:Antihypertensive Agents; D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical