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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

Corneal transect grid used to score corneal regions.
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f1-opth-5-1349: Corneal transect grid used to score corneal regions.

Mentions: Videos were analyzed for BUA using a corneal transect comprising 17 sections overlaying the cornea (regions A–Q in Figure 1). The presence or absence of breakup was graded for each applicable region (transect regions were deemed “not applicable” if they enclosed noncorneal anatomy alone). For example, in Figure 1, regions M, J, and I show areas of breakup. The BUA (% cornea exposed) in Figure 1 would be calculated as the areas of regions M, J, and I, divided by the total of areas A through Q. If a portion of the region had breakup, the whole area was deemed to have breakup and was included in the calculation of BUA. The total number of regions ranged from 15 to 17 depending on the position of the lids (eg, if the upper lid covered the top two regions, only 15 areas were included).


Measurement of ocular surface protection under natural blink conditions.

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

Corneal transect grid used to score corneal regions.
© Copyright Policy
Related In: Results  -  Collection

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

f1-opth-5-1349: Corneal transect grid used to score corneal regions.
Mentions: Videos were analyzed for BUA using a corneal transect comprising 17 sections overlaying the cornea (regions A–Q in Figure 1). The presence or absence of breakup was graded for each applicable region (transect regions were deemed “not applicable” if they enclosed noncorneal anatomy alone). For example, in Figure 1, regions M, J, and I show areas of breakup. The BUA (% cornea exposed) in Figure 1 would be calculated as the areas of regions M, J, and I, divided by the total of areas A through Q. If a portion of the region had breakup, the whole area was deemed to have breakup and was included in the calculation of BUA. The total number of regions ranged from 15 to 17 depending on the position of the lids (eg, if the upper lid covered the top two regions, only 15 areas were included).

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