FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Vet Ophthalmol / Serum albumin and total protein concentration in the tear fi...
Veterinary ophthalmology2020; 24(1); 20-27; doi: 10.1111/vop.12822

Serum albumin and total protein concentration in the tear film of horses with healthy or diseased eyes.

Abstract: To determine total protein content (TPC) and serum albumin levels in the tears of horses with healthy or diseased eyes. Methods: Forty-two horses with healthy eyes and 11 horses with unilateral (n = 10) or bilateral (n = 1) ocular disease. Methods: Each eye underwent an ophthalmic examination including detailed conjunctivitis scoring and tear collection with Schirmer strips. TPC and serum albumin levels were quantified in tear samples and compared among healthy eyes, affected eyes, and contralateral unaffected eyes. The impact of the following variables on lacrimal protein levels were assessed: age, breed, and sex (healthy eyes), as well as conjunctivitis score (diseased eyes). Results: Lacrimal TPC ranged from 7.0 to 19.5 mg/mL in healthy eyes, while serum albumin ranged from 71.1 to 711.3 µg/mL (~1.6% of TPC) and was higher in tears of aged and female horses (P ≤ .033). Eyes with ocular disease had significantly greater (P ≤ .001) serum albumin in tears (median 679.6 µg/mL) compared to contralateral unaffected eyes (130.0 µg/mL) and eyes of the reference population (200.7 µg/mL). However, lacrimal TPC did not differ significantly among the 3 groups. Scoring of palpebral conjunctival hyperemia trended toward a positive association with serum albumin in tears (r = 0.49, P = .062). Conclusions: The protein profile in equine tears differs in health and disease. Serum albumin in tears increases with ocular disease and, similar to other species, might serve as a biomarker for ocular insult in horses. Future studies could investigate the protein levels in horses with specific ocular conditions and help determine the biological importance of albumin on the equine ocular surface.
© 2020 American College of Veterinary Ophthalmologists.
Get Full Text
Publication Date: 2020-09-12 PubMed ID: 32920954DOI: 10.1111/vop.12822Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research paper aims to compare the levels of total protein content (TPC) and serum albumin in the tears of healthy horses and those with ocular diseases. The results reveal that serum albumin in tears increases with eye disease, which might act as a biomarker for ocular insult in horses.

Methodology

  • The study involved 42 horses with healthy eyes and 11 horses with either a unilateral (10 cases) or bilateral (1 case) eye disease.
  • Each eye underwent an extensive ophthalmic examination that included a detailed score of conjunctivitis and collection of tears with a Schirmer strip which is a standard method to test tear production.
  • The levels of total protein content (TPC) and serum albumin were quantified in the tear samples.
  • The investigators then compared these protein levels among healthily unaffected eyes, affected eyes, and the unaffected eyes of the horses with a diseased eye.
  • Variables that can potentially affect lacrimal protein levels, such as age, breed, and sex, were assessed for healthy eyes. In addition, a scoring of conjunctivitis was measured for diseased eyes.

Results

  • The total protein content in the tears of healthy eyes ranged between 7.0 and 19.5 mg/mL. The serum albumin levels in these tears varied from 71.1 to 711.3 μg/ml, which was approximately 1.6% of the TPC. Incidentally, older and female horses had slightly higher serum albumin levels.
  • Horses with ocular disease had a significantly higher amount of serum albumin in their tears compared to the unaffected eye and to the eyes of the control group.
  • However, there was no significant difference in TPC among healthy eyes, affected eyes, and contralateral unaffected eyes. This means that ocular disease did not significantly affect the total protein content in equine tears.
  • The score for palpebral conjunctival hyperemia (excessive blood flow to the conjunctiva, the membrane that covers the front of the eye) showed a trend towards positive association with serum albumin levels in the tears, meaning there could be a potential link between them.

Conclusion

  • The protein profile in equine tears changes between healthy and diseased states, notably with a significant increase in serum albumin levels in cases of ocular disease. This suggests that serum albumin could potentially serve as a biomarker for ocular diseases in horses.
  • The study suggests the need for future research to explore protein levels in horses with specific ocular conditions which can help to ascertain the biological importance of albumin on the equine ocular surface.

Cite This Article

APA
Terhaar HM, Allbaugh RA, Mochel JP, Sebbag L. (2020). Serum albumin and total protein concentration in the tear film of horses with healthy or diseased eyes. Vet Ophthalmol, 24(1), 20-27. https://doi.org/10.1111/vop.12822

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 24
Issue: 1
Pages: 20-27

Researcher Affiliations

Terhaar, Hannah M
  • Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
Allbaugh, Rachel A
  • Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
Mochel, Jonathan P
  • Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
Sebbag, Lionel
  • Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.
  • Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, USA.

MeSH Terms

  • Animals
  • Eye Diseases / blood
  • Eye Diseases / metabolism
  • Eye Proteins / metabolism
  • Female
  • Horse Diseases / blood
  • Horse Diseases / metabolism
  • Horses / blood
  • Horses / metabolism
  • Male
  • Reference Values
  • Serum Albumin / metabolism
  • Tears / metabolism

References

This article includes 30 references
  1. Kijlstra A, Kuizenga A. Analysis and function of the human tear proteins. Adv Exp Med Biol 1994;350:299-308.
  2. Fullard RJ, Kaswan RM, Bounous DI. Tear protein profiles vs. clinical characteristics of untreated and cyclosporine-treated canine KCS. J Am Optom Assoc 1995;66:397-404.
  3. Jung JH, Ji YW, Hwang HS. Proteomic analysis of human lacrimal and tear fluid in dry eye disease. Sci Rep 2017;7:13363.
  4. Sebbag L, Allbaugh RA, Weaver A. Histamine-induced conjunctivitis and breakdown of blood-tear barrier in dogs: a model for ocular pharmacology and therapeutics. Front Pharmacol 2019;10:752.
  5. Li K, Liu X, Chen Z. Quantification of tear proteins and sPLA2-IIa alteration in patients with allergic conjunctivitis. Mol Vis 2010;16:2084-2091.
  6. de Freitas CC, Cole N, Van Dyk D. Proteomic analysis of dog tears for potential cancer markers. Res Vet Sci 2008;85:349-352.
  7. Grus FH, Sabuncuo P, Dick HB. Changes in the tear proteins of diabetic patients. BMC Ophthalmol 2002;2:4.
  8. You J, Willcox MD, Madigan MC. Tear fluid protein biomarkers. Adv Clin Chem 2013;62:151-196.
  9. Hagan S, Martin E, Enríquez-de-Salamanca A. Tear fluid biomarkers in ocular and systemic disease: potential use for predictive, preventive and personalised medicine. EPMA J 2016;7:15.
  10. Clode AB. Therapy of equine infectious keratitis: a review. Equine Vet J Suppl 2010;19-23.
  11. Martín E, Molleda JM, Ginel PJ. Total protein and immunoglobulin concentrations in equine tears. Zentralbl Veterinarmed A 1997;44:461-465.
  12. Ollivier FJ, Brooks DE, Kallberg ME. Evaluation of various compounds to inhibit activity of matrix metalloproteinases in the tear film of horses with ulcerative keratitis. Am J Vet Res 2003;64:1081-1087.
  13. Ollivier FJ, Brooks DE, Van Setten GB. Profiles of matrix metalloproteinase activity in equine tear fluid during corneal healing in 10 horses with ulcerative keratitis. Vet Ophthalmol 2004;7:397-405.
  14. Runström G, Mann A, Tighe B. The fall and rise of tear albumin levels: a multifactorial phenomenon. Ocul Surf 2013;11:165-180.
  15. Sebbag L, Mochel JP. An eye on the dog as the scientist's best friend for translational research in ophthalmology: Focus on the ocular surface. Med Res Rev 2020.
    doi: 10.1002/med.21716google scholar: lookup
  16. Sebbag L, Harrington DM, Mochel JP. Tear fluid collection in dogs and cats using ophthalmic sponges. Vet Ophthalmol 2018;21:249-254.
  17. Posa A, Bräuer L, Schicht M. Schirmer strip vs. capillary tube method: non-invasive methods of obtaining proteins from tear fluid. Ann Anat 2013;195:137-142.
  18. Efron N, Al-Dossari M, Pritchard N. In vivo confocal microscopy of the palpebral conjunctiva and tarsal plate. Optom Vis Sci 2009;86:E1303-1308.
  19. Kapalschinski N, Seipp HM, Kückelhaus M. Albumin reduces the antibacterial efficacy of wound antiseptics against Staphylococcus aureus. J Wound Care 2017;26:184-187.
  20. Dalhoff A. Seventy-five years of research on protein binding. Antimicrob Agents Chemother 2018;62.
  21. Sebbag L, Moody LM, Mochel JP. Albumin levels in tear film modulate the bioavailability of medically-relevant topical drugs. Front Pharmacol 2019;10:1560.
  22. Tomlinson A, Khanal S. Assessment of tear film dynamics: quantification approach. Ocul Surf 2005;3:81-95.
  23. Chen T, Ward DA. Tear volume, turnover rate, and flow rate in ophthalmologically normal horses. Am J Vet Res 2010;71:671-676.
  24. Sebbag L, Allbaugh RA, Wehrman RF. Fluorophotometric assessment of tear volume and turnover rate in healthy dogs and cats. J Ocul Pharmacol Ther 2019;35:497-502.
  25. Riond B, Wenger-Riggenbach B, Hofmann-Lehmann R. Serum protein concentrations from clinically healthy horses determined by agarose gel electrophoresis. Vet Clin Pathol 2009;38:73-77.
  26. Lumsden JH, Mullen K, McSherry BJ. Canine hematology and biochemistry reference values. Can J Comp Med 1979;43:125-131.
  27. Sebbag L, Kass PH, Maggs DJ. Reference values, intertest correlations, and test-retest repeatability of selected tear film tests in healthy cats. J Am Vet Med Assoc 2015;246:426-435.
  28. Stuchell RN, Feldman JJ, Farris RL. The effect of collection technique on tear composition. Invest Ophthalmol Vis Sci 1984;25:374-377.
  29. Sebbag L, McDowell EM, Hepner PM. Effect of tear collection on lacrimal total protein content in dogs and cats: a comparison between Schirmer strips and ophthalmic sponges. BMC Vet Res 2018;14:61.
  30. Sebbag Lionel, Soler EA, Allbaugh RA. Impact of acute conjunctivitis on ocular surface homeostasis in dogs [published online ahead of print, 2020]. Vet Ophthalmol .
    doi: 10.1111/vop.12804google scholar: lookup
Subscribe to our newsletter
Join 99,105 horse owners like you who receive our email updates on horse health and nutrition.