Effective Treatments for Common Dog Eye Diseases: A Com

Eye diseases in dogs are quite common and are often treated with antibiotics and corticosteroids. Here are some of the most common ophthalmic conditions to be aware of: eyelid disorders (such as third eyelid hypertrophy and entropion), conjunctivitis, lacrimal disorders (like lacrimal duct obstruction and dry keratoconjunctivitis), corneal and scleral diseases (including keratitis and corneal trauma), lens disorders (such as cataracts and lens luxation), glaucoma, posterior eye diseases (like retinal detachment), eye injuries (such as globe prolapse), orbital diseases (such as orbital cellulitis), and eye tumors, among others.

When it comes to treating eye diseases, certain medications are commonly used:

1. Antibiotics:

Penicillin and penicillin derivatives can pass through the bloodaqueous humor barrier, making them effective for treating infections in the orbit, eyelids, and within the eye. They are often used for orbital and eyelid infections, and can be administered via subconjunctival injection. For infections of the conjunctiva, iris, or cornea, subconjunctival injections can be given after the eye has been flushed with penicillin saline. Following eye surgery, subconjunctival injections can be used before systemic treatment, and for superficial infections on the conjunctiva or cornea, the eye can be flushed with penicillin saline before subconjunctival injection.

Chloramphenicol is effective against Grampositive and Gramnegative bacteria, rickettsiae, spirochetes, and chlamydiae, but not against Pseudomonas aeruginosa. It is lipidsoluble and can cross the bloodbrain barrier, bloodaqueous humor barrier, and intact cornea. It can be administered orally, intramuscularly, subcutaneously, intravenously (50mg/kg every 8 hours), or via subconjunctival injection, or nasal lacrimal duct irrigation. Oral chloramphenicol is often recommended for posterior chamber inflammation.

Chloramphenicol ointment (1%) is a commonly used veterinary eye ointment, primarily for traumatic eye diseases. It can be used in conjunction with polymyxin B (Pseudomonas) before bacterial culture and sensitivity testing. It can be used as a last resort when no other antibiotics are effective.

Gentamicin and tobramycin are effective against Pseudomonas, Pseudomonas aeruginosa, Escherichia coli, Staphylococcus, Proteus, and Klebsiella. They can be administered subconjunctivally, but they have significant nephrotoxicity and ototoxicity, so they are not often used as firstline treatments. Gentamicin can also cause cataracts and retinal detachment if injected into the eye, so it should not be used longterm or in cases of corneal perforation. Tobramycin is similar to gentamicin and is recommended only when gentamicin is resistant to pseudomonas infections. It is generally used for eye irrigation, drops, or subconjunctival injection. Neomycin is the firstline treatment for pseudomonas infections, followed by gentamicin and amikacin.

Tetracycline is primarily used for treating chlamydial and mycoplasmal infections in the eye. It is available in ointment form and is generally not recommended for young animals.

Baytril is used for treating eyelid and orbital infections. It is administered orally at a dose of 2.5 to 5.0mg/kg and can enter tears to act on the eye after systemic administration.

2. Corticosteroids for the eyes:

Corticosteroids play a significant role in the treatment of eye diseases and are commonly used. Their antiinflammatory effects are strong, and they help reduce inflammatory exudates and alleviate clinical symptoms. However, they can also inhibit wound healing, corneal vascularization, and scar formation. It is important to use corticosteroids cautiously, as they can lower the body's resistance to many bacteria. Incorrect use of corticosteroids can lead to adverse effects, so it is essential to follow certain guidelines: corticosteroids should not be used when there is corneal fluorescein staining, whether topically or via subconjunctival injection. They should only be used when there is an immune or inflammatory reaction in the cornea or conjunctiva that needs to be controlled. Before using corticosteroids for any "redeyed" animal, corneal fluorescein staining and intraocular pressure measurement should be performed. Corticosteroids are not effective for primary glaucoma, and longterm topical use can lead to reversible adrenal cortical suppression. Other side effects are not common, unlike in humans, where they can cause glaucoma or cataracts.

3. Nonsteroidal antiinflammatory drugs (NSAIDs) for the eyes:

NSAIDs are useful in the treatment of eye diseases and do not have the side effects associated with corticosteroids. Common NSAIDs used in veterinary medicine include aspirin, flunixin meglumine, phenylbutazone, and tolmetin.

4. Local anesthetics for the eyes:

Local anesthetics are used for clinical examinations, treatments, and surgeries rather than for treatment. They can have several side effects, including hindering the normal growth of corneal epithelium and causing corneal punctate ulcers. Although they have an anesthetic effect, they can also cause allergic reactions in animals. Additionally, anesthesia can cause the affected eye to lose its protective reflexes, making it more susceptible to further corneal damage. Commonly used local anesthetics include procaine, lidocaine, cocaine, and 5% procaine ointment is the most commonly used.

5. Dry eye disease medications:

Since the corneal surface is lipophilic, waterbased solutions like saline cannot remain on the cornea for long and do not provide the same protection as tears. Therefore, it is important to use solutions that have both lipophilic and hydrophilic properties (or mucus) to protect the eyes. Artificial tear supplementation is necessary in the following situations: dry keratoconjunctivitis, exposure keratitis (due to facial nerve palsy), eyelid ectropion, insufficient tear production, to prevent corneal drying during anesthesia, as a lubricating agent for eye examinations, and to extend the contact time between eye drops and the cornea. Common tear substitutes used in veterinary medicine include polyvinylpyrrolidone, methylcellulose, and polyethylene glycol.

6. Medications to lower intraocular pressure (for treating glaucoma in dogs):

Osmotic agents (mannitol) increase the osmotic pressure in the local blood vessels of the eye, causing the aqueous humor to dehydrate and thereby reducing intraocular pressure. This process is slow and is primarily used in clinical ophthalmology for: reducing intraocular pressure in acute glaucoma, lowering intraocular pressure before intraocular surgery to clear corneal edema and allow for examination of the internal structures of the eye.