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Measurement of ocular surface protection under natural blink conditions.

Abelson R, Lane KJ, Angjeli E, Johnston P, Ousler G, Montgomery D - Clin Ophthalmol (2011)

Bottom Line: The traditional methodology (Forced-Stare [FS]) measures TFBUT and IBI separately.TFBUT (P = 0.034) and BUA/IBI (P = 0.001) were able to distinguish the treatment effect of artificial tears in dry-eye subjects.The VCMA methodology provides a clinically relevant analysis of tear film stability measured in the context of a natural blink pattern.

View Article: PubMed Central - PubMed

Affiliation: Arizona State University, Tempe, AZ, USA. rabelson@sdcclinical.com

ABSTRACT

Purpose: To evaluate a new method of measuring ocular exposure in the context of a natural blink pattern through analysis of the variables tear film breakup time (TFBUT), interblink interval (IBI), and tear film breakup area (BUA).

Methods: The traditional methodology (Forced-Stare [FS]) measures TFBUT and IBI separately. TFBUT is measured under forced-stare conditions by an examiner using a stopwatch, while IBI is measured as the subject watches television. The new methodology (video capture manual analysis [VCMA]) involves retrospective analysis of video data of fluorescein-stained eyes taken through a slit lamp while the subject watches television, and provides TFBUT and BUA for each IBI during the 1-minute video under natural blink conditions. The FS and VCMA methods were directly compared in the same set of dry-eye subjects. The VCMA method was evaluated for the ability to discriminate between dry-eye subjects and normal subjects. The VCMA method was further evaluated in the dry eye subjects for the ability to detect a treatment effect before, and 10 minutes after, bilateral instillation of an artificial tear solution.

Results: Ten normal subjects and 17 dry-eye subjects were studied. In the dry-eye subjects, the two methods differed with respect to mean TFBUTs (5.82 seconds, FS; 3.98 seconds, VCMA; P = 0.002). The FS variables alone (TFBUT, IBI) were not able to successfully distinguish between the dry-eye and normal subjects, whereas the additional VCMA variables, both derived and observed (BUA, BUA/IBI, breakup rate), were able to successfully distinguish between the dry-eye and normal subjects in a statistically significant fashion. TFBUT (P = 0.034) and BUA/IBI (P = 0.001) were able to distinguish the treatment effect of artificial tears in dry-eye subjects.

Conclusion: The VCMA methodology provides a clinically relevant analysis of tear film stability measured in the context of a natural blink pattern.

No MeSH data available.


Related in: MedlinePlus

Tear film breakup time observations for new (VCMA) and traditional (FS) methods for 17 dry-eye subjects (34 eyes). (A) Observed (yellow) and modeled (green, lognormal) histogram. (B) Scatter plot of the new versus traditional observations relative to a 45° reference line. Sample means were 4.0 for VCMA and 5.8 for FS.Abbreviations: FS, forced-stare; SD, standard deviation; VCMA, video capture manual analysis.
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f4-opth-5-1349: Tear film breakup time observations for new (VCMA) and traditional (FS) methods for 17 dry-eye subjects (34 eyes). (A) Observed (yellow) and modeled (green, lognormal) histogram. (B) Scatter plot of the new versus traditional observations relative to a 45° reference line. Sample means were 4.0 for VCMA and 5.8 for FS.Abbreviations: FS, forced-stare; SD, standard deviation; VCMA, video capture manual analysis.

Mentions: The mean TFBUTs for the traditional (FS) and the new (VCMA) methods were 5.82 and 3.98 seconds, respectively, for a ratio of 0.68 (P = 0.002), reflecting the very different methods used to measure these values. To provide a more meaningful comparison, TFBUTs for the traditional (FS) method were truncated to the corresponding IBI when no TFBUT was observed. This approach gave similar means, with a ratio of 1.18 (P = 0.348). Figure 4 shows histograms of both methods and scatter plots for individual data points. Figure 5 shows the corresponding plots using the truncated TFBUT values for the traditional (FS) method.


Measurement of ocular surface protection under natural blink conditions.

Abelson R, Lane KJ, Angjeli E, Johnston P, Ousler G, Montgomery D - Clin Ophthalmol (2011)

Tear film breakup time observations for new (VCMA) and traditional (FS) methods for 17 dry-eye subjects (34 eyes). (A) Observed (yellow) and modeled (green, lognormal) histogram. (B) Scatter plot of the new versus traditional observations relative to a 45° reference line. Sample means were 4.0 for VCMA and 5.8 for FS.Abbreviations: FS, forced-stare; SD, standard deviation; VCMA, video capture manual analysis.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3198408&req=5

f4-opth-5-1349: Tear film breakup time observations for new (VCMA) and traditional (FS) methods for 17 dry-eye subjects (34 eyes). (A) Observed (yellow) and modeled (green, lognormal) histogram. (B) Scatter plot of the new versus traditional observations relative to a 45° reference line. Sample means were 4.0 for VCMA and 5.8 for FS.Abbreviations: FS, forced-stare; SD, standard deviation; VCMA, video capture manual analysis.
Mentions: The mean TFBUTs for the traditional (FS) and the new (VCMA) methods were 5.82 and 3.98 seconds, respectively, for a ratio of 0.68 (P = 0.002), reflecting the very different methods used to measure these values. To provide a more meaningful comparison, TFBUTs for the traditional (FS) method were truncated to the corresponding IBI when no TFBUT was observed. This approach gave similar means, with a ratio of 1.18 (P = 0.348). Figure 4 shows histograms of both methods and scatter plots for individual data points. Figure 5 shows the corresponding plots using the truncated TFBUT values for the traditional (FS) method.

Bottom Line: The traditional methodology (Forced-Stare [FS]) measures TFBUT and IBI separately.TFBUT (P = 0.034) and BUA/IBI (P = 0.001) were able to distinguish the treatment effect of artificial tears in dry-eye subjects.The VCMA methodology provides a clinically relevant analysis of tear film stability measured in the context of a natural blink pattern.

View Article: PubMed Central - PubMed

Affiliation: Arizona State University, Tempe, AZ, USA. rabelson@sdcclinical.com

ABSTRACT

Purpose: To evaluate a new method of measuring ocular exposure in the context of a natural blink pattern through analysis of the variables tear film breakup time (TFBUT), interblink interval (IBI), and tear film breakup area (BUA).

Methods: The traditional methodology (Forced-Stare [FS]) measures TFBUT and IBI separately. TFBUT is measured under forced-stare conditions by an examiner using a stopwatch, while IBI is measured as the subject watches television. The new methodology (video capture manual analysis [VCMA]) involves retrospective analysis of video data of fluorescein-stained eyes taken through a slit lamp while the subject watches television, and provides TFBUT and BUA for each IBI during the 1-minute video under natural blink conditions. The FS and VCMA methods were directly compared in the same set of dry-eye subjects. The VCMA method was evaluated for the ability to discriminate between dry-eye subjects and normal subjects. The VCMA method was further evaluated in the dry eye subjects for the ability to detect a treatment effect before, and 10 minutes after, bilateral instillation of an artificial tear solution.

Results: Ten normal subjects and 17 dry-eye subjects were studied. In the dry-eye subjects, the two methods differed with respect to mean TFBUTs (5.82 seconds, FS; 3.98 seconds, VCMA; P = 0.002). The FS variables alone (TFBUT, IBI) were not able to successfully distinguish between the dry-eye and normal subjects, whereas the additional VCMA variables, both derived and observed (BUA, BUA/IBI, breakup rate), were able to successfully distinguish between the dry-eye and normal subjects in a statistically significant fashion. TFBUT (P = 0.034) and BUA/IBI (P = 0.001) were able to distinguish the treatment effect of artificial tears in dry-eye subjects.

Conclusion: The VCMA methodology provides a clinically relevant analysis of tear film stability measured in the context of a natural blink pattern.

No MeSH data available.


Related in: MedlinePlus