FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Equine veterinary journal2021; doi: 10.1111/evj.13496

Retrobulbar lidocaine injection via the supraorbital fossa is safe in adult horses but produces regionally variable periocular anaesthesia.

Abstract: Injection techniques for retrobulbar anaesthesia are published in horses, but neither safety nor anaesthetic efficacy and duration have been evaluated objectively in vivo. Objective: To characterise the safety and efficacy of one published technique for retrobulbar anaesthesia. Methods: Randomised, controlled descriptive experiment. Methods: Unilateral retrobulbar injection with 10 mL lidocaine (2%) was performed in eight sedated adult mares. Contralateral eyes served as untreated controls. Neurophthalmic parameters, intraocular pressure (IOP), and corneal and periocular sensation were measured awake, post-sedation and at periodic time points for 24 hours following injection. Adverse effects were documented. Results: Injection of 10 mL lidocaine significantly increased IOP for up to 2 hours (P < .05) maximally at 30 min (mean [95% CI]: 6.0 [2.7, 9.2] mm Hg, P < .001). Six of the eight treated eyes developed mild to moderate reversible chemosis for 2 to 24 hours. One eye developed severe chemosis and superficial corneal ulceration at 24 and 48 hours following injection respectively. Corneal sensitivity significantly decreased for 6 hours (P < .05), maximally at 10 min (-44.4 [-34.6, -54.1] mm, P < .001). Periocular sensitivity (measured as increase in applied force) significantly decreased dorsally and medially for up to 2 hours (maximal at 2 hours (367.1 [238.5, 495.7] g, P < .001, and at 30 min: 345.8 [202.6, 488.9] g, P < .001) respectively). Ventral and lateral sensitivity were not effectively decreased beyond 30 min. Optic nerve function was not consistently reduced following injection. Conclusions: Investigators were not masked to the treated eye. Conclusions: Retrobulbar injection using 10 mL lidocaine is safe in normal eyes of adult horses, but carries risk in structurally compromised or glaucomatous eyes due to transient IOP increase. Reversible chemosis commonly develops 2-4h following injection, and may be severe in some horses with risk for corneal ulceration. Corneal anaesthesia is rapid and prolonged, but all periocular regions are not consistently anaesthetised. Retrobulbar injection should be combined with other local anaesthetic injections for eyelid surgeries or enucleations.
© 2021 EVJ Ltd.
Get Full Text
Publication Date: 2021-08-16 PubMed ID: 34396584DOI: 10.1111/evj.13496Google 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 study investigates the effectiveness and safety of injecting lidocaine, a type of anesthetic, into the retrobulbar region (area behind the eyeball) of adult horses. The study found that this injection increases intraocular pressure and decreases ocular sensitivity but did not consistently reduce optic nerve function. In addition, it established that the technique is generally safe for horses with normal eyes but may pose risks for those with eye conditions.

Methods

  • The research was a randomized, controlled, descriptive experiment conducted on eight sedated adult mares.
  • Each horse received a unilateral retrobulbar injection with 10 mL of 2% lidocaine. The contralateral eyes (the eyes on the opposing side of where the injection was given) acted as untreated controls.
  • The researchers evaluated various neurophthalmic parameters, intraocular pressure (IOP), and the corneal and periocular (surrounding the eye) sensation. This evaluation was done when the horses were awake, after sedation, and at periodic intervals for 24 hours after the injection.
  • Any adverse effects from the injection were also noted.

Results

  • The injection of lidocaine caused a significant increase in IOP, reaching its peak at around 30 minutes after injection and lasting for up to two hours.
  • Six out of the eight treated eyes displayed mild to moderate reversible chemosis (a swelling of the surface of the eye) lasting between two to 24 hours. One eye developed severe chemosis and superficial corneal ulceration observed at 24 and 48 hours post-injection.
  • The sensitivity of the cornea significantly decreased for six hours, with its maximum reduction occurring ten minutes after the injection.
  • The sensitivity around the eyes decreased dorsally and medially for up to two hours, but sensitivity was not effectively reduced on the ventral (front) and lateral (side) regions beyond 30 minutes.
  • Optic nerve function wasn’t consistently affected by the injection.

Conclusions

  • The researchers concluded that a retrobulbar injection with 10 mL of lidocaine is safe for healthy adult horses, but it can pose risks for horses with pre-existing eye conditions or glaucoma due to the temporary increase in intraocular pressure.
  • Chemosis often develops 2-4 hours after the injection, and this swelling can be severe in some horses leading to corneal ulceration.
  • While the lidocaine injection rapidly and prolongedly numb the cornea, it doesn’t consistently numb all the regions around the eye.
  • The researchers suggested combining the retrobulbar injection with other local anesthetic injections when performing eyelid surgeries or enucleations (eye removal).

Cite This Article

APA
Yang VY, Eaton JS, Harmelink K, Hetzel SJ, Sanchez A, Lund JR, Smith LJ. (2021). Retrobulbar lidocaine injection via the supraorbital fossa is safe in adult horses but produces regionally variable periocular anaesthesia. Equine Vet J. https://doi.org/10.1111/evj.13496

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Yang, Vanessa Y
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Eaton, Joshua Seth
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Harmelink, Katherine
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Hetzel, Scott J
  • Department of Biostatistics and Medical Informatics, Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, USA.
Sanchez, Adriana
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Lund, Jane R
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Smith, Lesley J
  • Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, USA.

References

This article includes 45 references
  1. Raffe MR. Retrobulbar block in combination with general anaesthesia for equine ophthalmic surgery.. Veterinary Surgery 1986;139-41.
  2. Oel C, Gerhards H, Gehlen H. Effect of retrobulbar nerve block on heart rate variability during enucleation in horses under general anesthesia.. Vet Ophthalmol 2014;17:170-4.
  3. Pollock PJ, Russell T, Hughes TK, Archer MR, Perkins JD. Transpalpebral eye enucleation in 40 standing horses.. Vet Surg 2008;37:306-9.
  4. Curto EM, Griffith EH, Posner LP, Walsh KT, Balko JA, Gilger BC. Factors associated with postoperative complications in healthy horses after general anesthesia for ophthalmic versus non-ophthalmic procedures: 556 cases (2012-2014).. J Am Vet Med Assoc 2018;252:1113-9.
  5. Parviainen AK, Trim CM. Complications associated with anaesthesia for ocular surgery: a retrospective study 1989-1996.. Equine Vet J 2000;32:555-9.
  6. Stoppini R, Gilger B. Equire ocular examination basic techniques.. 2016:2-29.
  7. Labelle AL, Clark-Price SC. Anesthesia for ophthalmic procedures in the standing horse.. Vet Clin North Am Equine Pract 2013;29:179-91.
  8. Featherstone H, Heinrich C. Ophthalmic examination and diagnostics. Part 1: the eye examination and diagnostic procedures.. 2013.
  9. McKinney RA. The retrobulbar block: a review of techniques used and reported complications.. Equine Vet Educ 2020;33:332-6.
  10. Hefner E, Lin H, Cole R, Moore P, McMullen R. Comparison of the image quality from ocular coherence tomography examination of the equine cornea and retina using sedation and general anesthesia protocols with or without the use of local retrobulbar anesthesia.. Proceedings of the 51st Annual Scientific Meeting of the American College of Veterinary Ophthalmologists 2020.
  11. Gelatt KN, Gelatt JP. Veterinary ophthalmic surgery.. The Operating Room 2011.
  12. Kaps S, Richter M, Spiess BM. Corneal esthesiometry in the healthy horse.. Vet Ophthalmol 2003;6:151-5.
  13. Gordon E, Sandquist C, Cebra CK, Heidel J, Poulsen K, Schlipf JW. Esthesiometric evaluation of corneal analgesia after topical application of 1% morphine sulfate in normal horses.. Vet Ophthalmol 2018;21:218-23.
  14. Zibura AE, Salmon JH, Belda Lopez B, Lascelles BD, Westermeyer HD. Glaucoma-associated pain results in mechanical sensitivity changes in dogs: a pilot study.. Vet Ophthalmol 2021;24(Suppl 1):116-24.
  15. Knickelbein KE, Scherrer NM, Lassaline M. Corneal sensitivity and tear production in 108 horses with ocular disease.. Vet Ophthalmol 2018;21:76-81.
  16. Wotman KL, Utter ME. Effect of treatment with a topical ophthalmic preparation of 1% nalbuphine solution on corneal sensitivity in clinically normal horses.. Am J Vet Res 2010;71:223-8.
  17. Haussler KK. Pressure algometry for the detection of mechanical nociceptive thresholds in horses.. Animals (Basel) 2020;10:2195.
  18. Komáromy AM, Garg CD, Ying GS, Liu C. Effect of head position on intraocular pressure in horses.. Am J Vet Res 2006;67:1232-5.
  19. Andrade MCCD, Hünning PS, Pereira FQ, Dutra KP, Pigatto JAT. Lip twitch restraint on rebound tonometry in horses.. Ciencia Rural 2016;1486-90.
  20. Diehl K, Bowden AC. Effect of auriculopalpebral nerve block on equine intraocular pressure measured by rebound tonometry TonoVet.. Vet Ophthalmol 2020;23:368-73.
  21. Box G, Cox D. An analysis of transformations.. J Roy Stat Soc: Ser B (Methodol) 1964;26:211-43.
  22. Team R. R: a language and environment for statistical computing.. 2018.
  23. Bates D, Mächler M, Bolker BM, Walker SC. Fitting linear mixed-effects models using lme4.. J Stat Softw 2014;51.
  24. Joyner RL, Liu CC, Cremer J, Carter RT, Lewin AC. Intraocular pressure following four different intravenous sedation protocols in normal horses.. Equine Vet J 2021;53:612-7.
  25. Holve DL. Effect of sedation with detomidine on intraocular pressure with and without topical anesthesia in clinically normal horses.. J Am Vet Med Assoc 2012;240:308-11.
  26. Trbolova A, Ghaffari MS. Effects of intravenous detomidine on intraocular pressure readings obtained by applanation tonometry in clinically normal horses.. J Equine Vet Sci 2013;182-5.
  27. Sebbag L, Allbaugh RA, Weaver A, Seo YJ, Mochel JP. Histamine-induced conjunctivitis and breakdown of blood-tear barrier in dogs: a model for ocular pharmacology and therapeutics.. Front Pharmacol 2019;10:752.
  28. Gilger BC, Davidson MG. How to prepare for ocular surgery in the standing horse.. Proc Am Assoc Equine Pract 2002;48:266-71.
  29. Shilo-Benjamini Y. A review of ophthalmic local and regional anesthesia in dogs and cats.. Vet Anaesth Analg 2019;46:14-27.
  30. Hewes CA, Keoughan GC, Gutierrez-Nibeyro S. Standing enucleation in the horse: a report of 5 cases.. Can Vet J 2007;48:512-4.
  31. Morath U, Luyet C, Spadavecchia C, Stoffel MH, Hatch GM. Ultrasound-guided retrobulbar nerve block in horses: a cadaveric study.. Vet Anaesth Analg 2013;40:205-11.
  32. Pakkanen SA, Raekallio MR, Mykkänen AK, Salla KM, de Vries A, Vuorilehto L. Detomidine and the combination of detomidine and MK-467, a peripheral alpha-2 adrenoceptor antagonist, as premedication in horses anaesthetized with isoflurane.. Vet Anaesth Analg 2015;42:527-36.
  33. Evans HE, Miller ME. Miller's Anatomy of the Dog, 4th ed.. 2013.
  34. Freeman SL, England GC. Investigation of romifidine and detomidine for the clinical sedation of horses.. Vet Rec 2000;147:507-11.
  35. Moens Y, Lanz F, Doherr MG, Schatzmann U. A comparison of the antinociceptive effects of xylazine, detomidine and romifidine on experimental pain in horses.. Vet Anaesth Analg 2003;30:183-90.
  36. Rohrbach H, Korpivaara T, Schatzmann U, Spadavecchia C. Comparison of the effects of the alpha-2 agonists detomidine, romifidine and xylazine on nociceptive withdrawal reflex and temporal summation in horses.. Vet Anaesth Analg 2009;36:384-95.
  37. du Toit R, Vega JA, Fonn D, Simpson T. Diurnal variation of corneal sensitivity and thickness.. Cornea 2003;22:205-9.
  38. Strian F, Lautenbacher S, Galfe G, Hölzl R. Diurnal variations in pain perception and thermal sensitivity.. Pain 1989;36:125-31.
  39. Dorbandt DM, Labelle AL, Mitchell MA, Hamor RE. The effects of topical diclofenac, topical flurbiprofen, and humidity on corneal sensitivity in normal dogs.. Vet Ophthalmol 2017;20:160-70.
  40. King C, Evans D, Rose R. Acclimation to treadmill exercise.. Equine Vet J 1995;27:453-6.
  41. Coleman KD, Schmiedt CW, Kirkby KA, Coleman AE, Robertson SA, Hash J. Learning confounds algometric assessment of mechanical thresholds in normal dogs.. Vet Surg 2014;43:361-7.
  42. Rabbogliatti V, De Zani D, Zani DD, Di Cesare F, Brioschi FA, Gioeni D. Comparison of four peribulbar anaesthetic techniques: a preliminary study in equine cadavers.. Vet Anaesth Analg 2020.
  43. Accola PJ, Bentley E, Smith LJ, Forrest LJ, Baumel CA, Murphy CJ. Development of a retrobulbar injection technique for ocular surgery and analgesia in dogs.. J Am Vet Med Assoc 2006;229:220-5.
  44. Hoch MJ, Bruno MT, Shepherd TM. Advanced MRI of the optic nerve.. J Neuroophthalmol 2017;37:187-96.
  45. Ozgen A, Aydingöz U. Normative measurements of orbital structures using MRI.. J Comput Assist Tomogr 2000;24:493-6.

Citations

This article has been cited 1 times.
  1. Hermans H, Lloyd-Edwards RA, Ferrão-van Sommeren AJH, Tersmette AA, Schouten JCM, Serra Bragança FM, van Loon JPAM. Comparing Blind and Ultrasound-Guided Retrobulbar Nerve Blocks in Equine Cadavers: The Training Effect. Animals (Basel) 2022 Jan 9;12(2).
    doi: 10.3390/ani12020154pubmed: 35049776google scholar: lookup
Subscribe to our newsletter
Join 99,727 horse owners like you who receive our email updates on horse health and nutrition.