Clin Ophthalmol. 2011;5:1349-57. doi: 10.2147/OPTH.S22017. Epub 2011 Sep 22.

Measurement of ocular surface protection under natural blink conditions.

Clinical ophthalmology (Auckland, N.Z.)

Richard Abelson, Keith J Lane, Endri Angjeli, Patrick Johnston, George Ousler, Douglas Montgomery

PMID: 22034554 PMCID: PMC3198408 DOI: 10.2147/OPTH.S22017

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.

Keywords: forced stare; interblink interval; ocular protection index; tear film breakup time

References

1. Ocul Surf. 2005 Jul;3(3):143-54 - PubMed
2. Ophthalmologica. 1985;190(3):147-9 - PubMed
3. Exp Eye Res. 1961 Sep;1:39-45 - PubMed
4. Adv Exp Med Biol. 1998;438:55-62 - PubMed
5. Exp Eye Res. 1973 May 10;15(5):515-25 - PubMed
6. Int Ophthalmol Clin. 1973 Spring;13(1):97-102 - PubMed
7. Optom Vis Sci. 2006 Oct;83(10):723-30 - PubMed
8. Cornea. 2008 Jun;27(5):509-13 - PubMed
9. Cornea. 2007 Sep;26(8):949-52 - PubMed
10. Exp Eye Res. 1980 Apr;30(4):411-25 - PubMed
11. Surv Ophthalmol. 2001 Mar;45 Suppl 2:S203-10 - PubMed
12. Cornea. 2008 Jul;27(6):656-62 - PubMed
13. Adv Exp Med Biol. 2002;506(Pt B):1121-5 - PubMed
14. Curr Eye Res. 1999 Jul;19(1):4-11 - PubMed
15. Optom Vis Sci. 2006 Jan;83(1):15-21 - PubMed
16. Invest Ophthalmol. 1975 Mar;14(3):255-8 - PubMed

Publication Types

• Journal Article