Abstract
PURPOSE. To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. METHODS. Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area. Balanced salt solution Plus (BSS+) and a 2% hydroxypropylmethylcellulose viscoelastic were used as the test agents. The tear film evaporation rate was characterized and compared over a period of 20 minutes in 20 eyes from 10 New Zealand white rabbits. RESULTS. The ellipse axes ratio and surface area were found to decrease initially after each application of either viscoelastic or BSS+ and then to increase linearly as the tear film began to evaporate (P < 0.001) for eyes treated with BSS+ only. Eyes treated with BSS+ required 7.5 ± 2.7 applications to maintain sufficient corneal hydration during the 20-minute test period, whereas eyes treated with viscoelastic required 1.4 ± 0.5 applications. The rates of evaporation differed significantly (P < 0.043) between viscoelastic and BSS+. CONCLUSIONS. The shape and surface area of the corneal reflection are strongly correlated with the state of the tear film. Rabbits' corneas treated with viscoelastic remained hydrated significantly longer than corneas treated with BSS+.
| Original language | English |
|---|---|
| Pages (from-to) | 4158-4163 |
| Number of pages | 6 |
| Journal | Investigative Ophthalmology and Visual Science |
| Volume | 55 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jun 19 2014 |
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Keywords
- Balanced salt solution
- Corneal hydration
- Evaporation
- Precorneal tear film stability
- Viscoelastic
ASJC Scopus subject areas
- Ophthalmology
- Sensory Systems
- Cellular and Molecular Neuroscience
Cite this
A new, specular reflection-based, precorneal tear film stability measurement technique in a rabbit model : Viscoelastic increases tear film stability. / Nankivil, Derek; Gonzalez, Alex; Arrieta Quintero, Esdras; Rowaan, Cornelis; Aguilar, Mariela C.; Sotolongo, Krystal; Cabot, Florence A.; Yoo, Sonia H; Parel, Jean-Marie A.
In: Investigative Ophthalmology and Visual Science, Vol. 55, No. 7, 19.06.2014, p. 4158-4163.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A new, specular reflection-based, precorneal tear film stability measurement technique in a rabbit model
T2 - Viscoelastic increases tear film stability
AU - Nankivil, Derek
AU - Gonzalez, Alex
AU - Arrieta Quintero, Esdras
AU - Rowaan, Cornelis
AU - Aguilar, Mariela C.
AU - Sotolongo, Krystal
AU - Cabot, Florence A.
AU - Yoo, Sonia H
AU - Parel, Jean-Marie A
PY - 2014/6/19
Y1 - 2014/6/19
N2 - PURPOSE. To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. METHODS. Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area. Balanced salt solution Plus (BSS+) and a 2% hydroxypropylmethylcellulose viscoelastic were used as the test agents. The tear film evaporation rate was characterized and compared over a period of 20 minutes in 20 eyes from 10 New Zealand white rabbits. RESULTS. The ellipse axes ratio and surface area were found to decrease initially after each application of either viscoelastic or BSS+ and then to increase linearly as the tear film began to evaporate (P < 0.001) for eyes treated with BSS+ only. Eyes treated with BSS+ required 7.5 ± 2.7 applications to maintain sufficient corneal hydration during the 20-minute test period, whereas eyes treated with viscoelastic required 1.4 ± 0.5 applications. The rates of evaporation differed significantly (P < 0.043) between viscoelastic and BSS+. CONCLUSIONS. The shape and surface area of the corneal reflection are strongly correlated with the state of the tear film. Rabbits' corneas treated with viscoelastic remained hydrated significantly longer than corneas treated with BSS+.
AB - PURPOSE. To develop a safe, noninvasive, noncontact, continuous in vivo method to measure the dehydration rate of the precorneal tear film and to compare the effectiveness of a viscoelastic agent in maintaining the precorneal tear film to that of a balanced salt solution. METHODS. Software was designed to analyze the corneal reflection produced by the operating microscope's coaxial illumination. The software characterized the shape of the reflection, which became distorted as the precorneal tear film evaporated; characterization was accomplished by fitting an ellipse to the reflection and measuring its projected surface area. Balanced salt solution Plus (BSS+) and a 2% hydroxypropylmethylcellulose viscoelastic were used as the test agents. The tear film evaporation rate was characterized and compared over a period of 20 minutes in 20 eyes from 10 New Zealand white rabbits. RESULTS. The ellipse axes ratio and surface area were found to decrease initially after each application of either viscoelastic or BSS+ and then to increase linearly as the tear film began to evaporate (P < 0.001) for eyes treated with BSS+ only. Eyes treated with BSS+ required 7.5 ± 2.7 applications to maintain sufficient corneal hydration during the 20-minute test period, whereas eyes treated with viscoelastic required 1.4 ± 0.5 applications. The rates of evaporation differed significantly (P < 0.043) between viscoelastic and BSS+. CONCLUSIONS. The shape and surface area of the corneal reflection are strongly correlated with the state of the tear film. Rabbits' corneas treated with viscoelastic remained hydrated significantly longer than corneas treated with BSS+.
KW - Balanced salt solution
KW - Corneal hydration
KW - Evaporation
KW - Precorneal tear film stability
KW - Viscoelastic
UR - http://www.scopus.com/inward/record.url?scp=84903976143&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903976143&partnerID=8YFLogxK
U2 - 10.1167/iovs.14-14157
DO - 10.1167/iovs.14-14157
M3 - Article
C2 - 24948606
AN - SCOPUS:84903976143
VL - 55
SP - 4158
EP - 4163
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
SN - 0146-0404
IS - 7
ER -