Effect of chronic anti-glaucoma medications and trabeculectomy on tear osmolarity

Abstract

Purpose To evaluate the tear film osmolarity (TFO) and ocular surface clinical signs and symptoms in chronically medicated glaucoma patients and post-trabeculectomy patients. Methods This is a single-center, prospective case-controlled study. One-hundred and thirty eyes of 130 participants aged Z45 years were included (49 normal controls, 50 glaucoma patients on chronic preserved antiglaucoma medication Z6 months, and 31 post-trabeculectomy patients not on medication Z6 months). TFO, tear break-up time (TBUT), Schirmer's test I and dry eye symptoms were evaluated. Data from both groups of glaucoma patients were compared with age and sex-matched controls. Logistic regression was performed to calculate the odds ratios. Results Mean TFO in the three groups were 301.4 ± 7.7, 307.0 ± 9.3, and 307.4 ± 11.6 mOsm/l, respectively. Compared with normal controls, chronically medicated glaucoma patients and post-trabeculectomy patients were more likely to have a raised TFO, with odds ratios (95% CI) of 4.43 (1.74-11.32) and 2.76 (1.02-7.94), respectively. Both groups of glaucoma patients were also more likely to experience dry eye symptoms, with ORs of 4.72 (1.92-11.59) and 4.24 (1.54-11.72). There was no significant difference in TFO and symptoms between both groups of glaucoma patients, and in TBUT and Schirmer's test across all three groups. Conclusions Patients on chronic topical antiglaucoma medication and posttrabeculectomy patients were more likely to have raised TFO and dry eye symptoms, suggesting significant ocular surface disease. Glaucoma practitioners should be aware that dry eye symptoms and raised TFO may occur in the absence of TBUT and Schirmer's test abnormality.

Meibomian gland loss due to trabeculectomy

“…Results from previous studies have led researchers to speculate on a relationship between OSD and meibomian gland loss and tear dysfunctions, including raised tear film osmolarity after trabeculectomy [5,6,8,30]. If such a relationship does exist, the question remains as to why meibomian gland loss, tear dysfunction, and OSD occur after trabeculectomy.…”

“…Because meibomian gland secretions prevent water evaporation [11,12], severe meibomian gland loss can induce an increase in water evaporation and tear film hyperosmolarity after trabeculectomy. Since tear film hyperosmolarity leads to ocular surface inflammation and damage [5,[34][35][36], this inflammation may accelerate meibomian gland loss not only in the bleb-contacting areas but also in the bleb-noncontacting areas. However, it should be noted that in our study, we did not analyze tear film osmolarity.…”

“…However, the use of these antiproliferative agents may lead to tear film abnormalities and ocular surface complications, including defects in the conjunctival epithelium of the filtering bleb surface [1][2][3][4][5][6][7]. Defects in the conjunctival epithelium that covers the bleb wall are precursors to lateonset bleb leaks.…”

Tear Film Osmolarity in Subjects with Acute Allergic Rhinoconjunctivitis

“…Tear osmolarity was higher in both groups (means 307.0±9.3 and 307.4±11.6mOsm/l, respectively) compared to healthy individuals (mean 301.4 ±7.7mOsm/l). However, no statistically significant differences neither in tear osmolarity nor in BUT and Schirmer's test scores were detected among the three groups (23).…”

One Year of Glaucoma Research in Review

“…In order to investigate the effects of glaucoma therapy on the ocular surface, Lee and colleagues 41 performed a single-center prospective case-control study including 49 normal control subjects, 50 glaucoma patients on chronic preserved antiglaucoma medications (≥6 months), and 31 posttrabeculectomy patients. They found that both subsets of glaucoma patients had an elevated tear film osmolarity (ORs, 4.43 and 2.76 for medically treated and posttrabeculectomy patients, respectively) and were also more likely to experience dry eye symptoms (ORs, 4.72 and 4.24).…”