Purpose:
To evaluate tear film osmolarity in patients treated with intraocular pressure-lowering medications.
Methods:
Forty patients treated for glaucoma or ocular hypertension (OHT) and followed at the Quinze-Vingts National Ophthalmology Hospital were consecutively recruited for the study. Each patient was asked to complete an evaluation of ocular surface disease (OSD) symptoms and underwent a complete evaluation of the ocular surface including tear film osmolarity, Schirmer test, tear film breakup time (TBUT) and, corneal and conjunctival staining. Demographic information and glaucoma treatment were obtained from patient’s medical records.
Results:
Twenty eight patients (70%) had chronic glaucoma and 12 (30%) had OHT. There were 20 women and 20 men with a mean ± SD age of 63.9 ± 10.8 years. Twenty four patients (60%) reported OSD symptoms according to the OSDI. Nineteen patients (47.5%) had a tear osmolarity ≤ 308 mOsms/L, 11 (27.5%) between 309-328 mOsms/L and 10 (25%) > 328 mOsms/L. According to Schirmer test, a tear deficiency was observed in 20 patients (50%). Twenty seven patients (67.5%) had an abnormal tear quality analyzed with tear breakup time (TBUT) and 16 patients (40%) showed positive staining using the Oxford schema. There was a statistically significant correlation between tear osmolarity and the number of molecules (r=0.409, p=0.009), the number of instillations (r=0.405, p=0.01) and the number of instillations of preserved eyedrops (r=0.629, p<0.0001). Using the multiple regression method, tear osmolarity remained significantly correlated to the number of instillations of preserved eyedrops (p=0,004). Tear osmolarity was significantly correlated to OSDI (r=0.486; p=0.002) and TBUT (r=-0.49; p=0.009).
Conclusions:
Tear osmolarity was increased in patients treated for glaucoma or OHT, particularly in those using multiple preserved eyedrops. The evaluation of the ocular surface of patients treated for glaucoma or OHT may benefit from such analysis and future trials for new intraocular pressure-lowering eyedrops should thus evaluate tear osmolarity.
Keywords: drug toxicity/drug effects • cornea: tears/tear film/dry eye • clinical (human) or epidemiologic studies: prevalence/incidence