Limits...
Effectiveness of dry eye therapy under conditions of environmental stress.

Tomlinson A, Madden LC, Simmons PA - Curr. Eye Res. (2013)

Bottom Line: Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11).There were no significant treatment effects on tear film structure.Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients.

View Article: PubMed Central - PubMed

Affiliation: Vision Sciences, Glasgow Caledonian University, Glasgow, UK. a.tomlinson@gcu.ac.uk

ABSTRACT

Purpose: Dry eye is often characterized by increased tear evaporation due to poor tear film quality, especially of the lipid component of the tear film. Using an environmental chamber to induce environmental stress, this study compared the effect of three lubricant eye drops on various aspects of tear physiology in a crossover design (evaporation was the principal outcome measure).

Methods: Three eye drop formulas were tested: 0.5% carmellose sodium (Drop C), 0.5% carmellose sodium with added lipid (Drop C-L) and 1.0% glycerine with added lipid (Drop G-L). Nineteen control and 18 dry eye subjects used each product for 2 weeks, three times per day, in a random order, with a minimum 1-week washout between treatment periods. Tear evaporation, break up time, osmolarity, tear structure (by interferometry) and patient symptoms were assessed with the subjects adapted for 10 min in an environmental chamber controlled at 20% relative humidity and 22 °C. The treatment effects were analyzed using general linear model repeated measures analyses of variance.

Results: In dry eye subjects, evaporation, break up time, osmolarity and symptoms improved for all formulas (p < 0.05). Normal subjects showed some improvements: evaporation with C-L, osmolarity with C and symptoms with C-L and G-L. Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11). There were no significant treatment effects on tear film structure.

Conclusion: Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients. This study also demonstrates the utility of a controlled environmental chamber in showing the difference in performance between dry eye treatments.

Show MeSH

Related in: MedlinePlus

Estimated marginal means of evaporation rate pre and post treatment for each therapy. (a) Dry eye patient data. (b) Control patient data. The before and after data for other measures can be seen in Tables 1 and 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3585441&req=5

f1: Estimated marginal means of evaporation rate pre and post treatment for each therapy. (a) Dry eye patient data. (b) Control patient data. The before and after data for other measures can be seen in Tables 1 and 2.

Mentions: Comparisons of the tear physiology measures before and after treatment with the three solutions showed significant statistical changes after treatment for the following: (decreased) tear evaporation rate (with Drop C-L in controls (p = 0.010) and all solutions in dry eye (p = 0.0001) (Figure 1); (improved) symptoms (OSDI score) (with Drop C-L (p = 0.013) and Drop G-L (p = 0.011) in controls and all solutions for dry eye (p = 0.001); NITBUT (no change in controls and all solutions in dry eye (Drop C (p < 0.0001), Drop C-L (p = 0.002) and Drop G-L (p = 0.008)) (reduced) are osmolarity (Drop C for controls (p = 0.031) and all solutions for dry eye (Drop C = 0.003, Drop C-L (p < 0.0001) and Drop G-L (p = 0.001)). No significant changes in the tear stability by interferometry were found for either subject group with any treatment (p > 0.05).Figure 1. 


Effectiveness of dry eye therapy under conditions of environmental stress.

Tomlinson A, Madden LC, Simmons PA - Curr. Eye Res. (2013)

Estimated marginal means of evaporation rate pre and post treatment for each therapy. (a) Dry eye patient data. (b) Control patient data. The before and after data for other measures can be seen in Tables 1 and 2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3585441&req=5

f1: Estimated marginal means of evaporation rate pre and post treatment for each therapy. (a) Dry eye patient data. (b) Control patient data. The before and after data for other measures can be seen in Tables 1 and 2.
Mentions: Comparisons of the tear physiology measures before and after treatment with the three solutions showed significant statistical changes after treatment for the following: (decreased) tear evaporation rate (with Drop C-L in controls (p = 0.010) and all solutions in dry eye (p = 0.0001) (Figure 1); (improved) symptoms (OSDI score) (with Drop C-L (p = 0.013) and Drop G-L (p = 0.011) in controls and all solutions for dry eye (p = 0.001); NITBUT (no change in controls and all solutions in dry eye (Drop C (p < 0.0001), Drop C-L (p = 0.002) and Drop G-L (p = 0.008)) (reduced) are osmolarity (Drop C for controls (p = 0.031) and all solutions for dry eye (Drop C = 0.003, Drop C-L (p < 0.0001) and Drop G-L (p = 0.001)). No significant changes in the tear stability by interferometry were found for either subject group with any treatment (p > 0.05).Figure 1. 

Bottom Line: Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11).There were no significant treatment effects on tear film structure.Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients.

View Article: PubMed Central - PubMed

Affiliation: Vision Sciences, Glasgow Caledonian University, Glasgow, UK. a.tomlinson@gcu.ac.uk

ABSTRACT

Purpose: Dry eye is often characterized by increased tear evaporation due to poor tear film quality, especially of the lipid component of the tear film. Using an environmental chamber to induce environmental stress, this study compared the effect of three lubricant eye drops on various aspects of tear physiology in a crossover design (evaporation was the principal outcome measure).

Methods: Three eye drop formulas were tested: 0.5% carmellose sodium (Drop C), 0.5% carmellose sodium with added lipid (Drop C-L) and 1.0% glycerine with added lipid (Drop G-L). Nineteen control and 18 dry eye subjects used each product for 2 weeks, three times per day, in a random order, with a minimum 1-week washout between treatment periods. Tear evaporation, break up time, osmolarity, tear structure (by interferometry) and patient symptoms were assessed with the subjects adapted for 10 min in an environmental chamber controlled at 20% relative humidity and 22 °C. The treatment effects were analyzed using general linear model repeated measures analyses of variance.

Results: In dry eye subjects, evaporation, break up time, osmolarity and symptoms improved for all formulas (p < 0.05). Normal subjects showed some improvements: evaporation with C-L, osmolarity with C and symptoms with C-L and G-L. Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11). There were no significant treatment effects on tear film structure.

Conclusion: Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients. This study also demonstrates the utility of a controlled environmental chamber in showing the difference in performance between dry eye treatments.

Show MeSH
Related in: MedlinePlus