ISSN 2398-2977      

Therapeutics: eye



  • Always demonstrate administration of drugs to the eye for owners who will be instilling preparations unsupervised.
  • Culture and sensitivity/cytology is a routine part of the diagnosis of eye infections → modify initial broad-spectrum antibiosis according to microbiologic results.
  • Topical preparations are preferable to systemic.
  • If medication is applied bilaterally where one eye is being treated prophylactically, treat the unaffected eye first to avoid cross contamination during administration.
  • There are 3 barriers to the passage of drugs into the eye:
    • Corneal epithelial layer.
    • Blood-aqueous barrier. 
    • Blood-retinal barrier.
  • Corneal epithelial layer:
  • Blood aqueous barrier:
    • Junctions between cells of the non-pigmented ciliary body epithelium and the iris capillary endothelium.
  • Blood retinal barrier:
    • Intercellular junctions:
      • Vascular endothelium of retinal vessels and choroidal vessels.
      • Retinal pigment epithelium.
  • Factors determining how well drugs cross these barriers:
    • * Lipid solubility.
    • * Hydrophilic or polar drugs.
    • * Protein binding affinity.
    • Molecular weight.
  • Damage or disease to barriers: affects their function - usually increasing the passage of drugs, eg uveitis Uveitis: anterior - overview.
  • Topics contained within this section:
    • Anti-infectives.
    • Anti-inflammatories.
    • Mydriatics and cycloplegics.
    • Local anesthetics.
    • Miscellaneous preparations and uses.
    • Methods of administration.

Types of drugs available for therapy of the eye

  • Antibiotics:
    • Topical.
    • Subconjunctival.
    • Systemic.
    • Intra-ocular.
  • Antifungals:
    • Topical.
    • Subconjunctival (miconazole Miconazole).
  • Antiviral:
    • Topical only.
  • Anti-inflammatory drugs:
    • Corticosteroids - topical/subconjunctival/systemic.
    • Non-steroidal drugs - topical/systemic.
    • Antihistamines - topical/systemic.
    • DMSO Dimethyl sulfoxide - topical/systemic.
  • Autonomic drugs:
    • Parasympathomimetics (miotics) - topical.
    • Parasympatholytics (mydriatics) - topical.
    • Sympathomimetics - topical.
  • Disinfectants:
    • 1% povidone-iodine Povidone-iodine solution diluted in saline - topical.
  • Corneal dehydrating agents:
    • 5% hypertonic saline ointment - topical.
  • Artificial tears - topical.
  • Ocular lubricants - topical.
  • Anticollagenase drugs - topical:
    • EDTA:
      • 0.2-1% K or Na EDTA in artificial tears.
      • 5 ml saline in 7 ml vacutainer EDTA anticoagulant.
      • Impairs healing - withdraw rapidly once repair started.
    • Acetylcysteine:
      • 5% mucinolytic → long-term degrades tear film.
      • 2-3 days at most.
    • Serum.
    • Povidone-iodine Povidone-iodine.
    • Tetracycline Therapeutics: tetracyclines:
      • Doxycycline 0.1% solution in artificial tears.
      • q1-2h.
  • Irrigating solutions - topical:


This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login


This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Mydriatics and others

This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login


This article is available in full to registered subscribers

Sign up now to obtain ten tokens to view any ten Vetlexicon articles, images, sounds or videos, or Login

Further Reading


Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Lavach J K et al (1984) Current concepts in equine ocular therapeutics. Vet Clin North Am Large Anim Pract (3), 435-449 PubMed.
  • Tammeus J et al (1983) Therapeutic extended wear contact lens for corneal injury in a horse.  JAVMA 182 (3), 286 PubMed.
  • Frauenfelder H et al (1979) Placement of a subpalpebral catheter in a standing horse. Vet Med Small Anim Clin 74 (5), 724-730 PubMed.

Other sources of information

  • Matthews A (2004) Ophthalmic Therapeutics. In: Equine Clinical Pharmacology. Eds: Bertone J J & Horspool L J I. Saunders, UK. pp 217-245.
  • Derived from The Veterinary Formulary (2001) Ed: Bishop Y. 5th edn. Pharmaceutical Press; published is association with the British Veterinary Association, UK.

Related Images


Abdomen: pain - adult

Acetylsalicylic acid


Anesthesia: general - overview

Anesthesia: local - overview

Anesthesia: regional - head

Anesthesia: standing chemical restraint

Aspergillus spp

Atropine sulfate

Benzathine cloxacillin


Chlamydophila spp



Clostridia spp


Conjunctivitis: chlamydial

Cornea / conjunctiva: scraping

Cornea: debridement

Cornea: fluorescein dye test

Cornea: foreign body



Dimethyl sulfoxide


Equine herpesvirus

Eye: anesthesia

Eye: biopsy

Eye: dacryocystitis

Eye: drug administration - contact lens

Eye: drug administration - subconjunctival injection

Eye: drug administration - systemic

Eye: drug administration 01 - topical

Eye: drug administration 02 - topical

Eye: examination - dark - mydriasis

Eye: examination - lighted

Eye: examination - physical

Eye: glaucoma

Eye: panophthalmitis

Eyeball: tonometry

Eyelid: entropion

Eyelid: tarsorrhaphy - temporary


Fluid therapy: lactated Ringer's solution

Flunixin meglumine

Foot: laminitis

Gastrointestinal: ileus


Hydroxypropyl methylcellulose


Keratitis: mycotic

Keratitis: overview

Keratitis: pigmentary

Keratitis: traumatic - ulcerative



Moraxella equi




Optic nerve: neuritis

Orbit: fracture repair

Orbit: retrobulbar abscess

Orbit: trauma


Polymyxin B



Proteus spp

Pseudomonas spp

Skin: onchocerciasis

Sodium chloride

Sodium hyaluronate

Staphylococcus spp

Streptococcus spp


Therapeutics: aminoglycosides

Therapeutics: anti-inflammatory drugs

Therapeutics: antimicrobials

Therapeutics: beta-lactam antibacterials

Therapeutics: chloramphenicol

Therapeutics: nitrofurans - nitroimidazoles - quinolones

Therapeutics: performance

Therapeutics: tetracyclines

Third eyelid: excision



Ultrasonography: eye

Uveitis: anterior - neoplasia-induced

Uveitis: anterior - overview

Uveitis: recurrent

Want more related items, why not
contact us

Can’t find what you’re looking for?

We have an ever growing content library on Vetlexicon so if you ever find we haven't covered something that you need please fill in the form below and let us know!


To show you are not a Bot please can you enter the number showing adjacent to this field

 Security code