Figure 18-1
Anterior chamber Cornea Vitreous chamber Sclera Choroid coat Retina Iris Fovea Lens Blind spot Posterior chamber Optic nerve Figure 18-2
Lateral canthus Cilia (eyelashes) Nictitating membrane Dorsal lacrimal punctum Medial canthus Pupil Lacrimal canaliculi Iris Cilia Ventral lacrimal punctum Lacrimal sac Nasolacrimal duct To nose Figure 18-3
Figure18-4 A
Figure 18-4 B
Figure 18-5
Figure 18-6
Trabecular meshwork Canal of Schlemm Normal angle Trabecular meshwork Iris Cornea Canal of Schlemm Anterior chamber Lens Ciliary process Posterior chamber Pupillary aperture Ciliary muscle Trabecular meshwork Canal of Schlemm Narrowed angle Trabecular meshwork Iris Cornea Canal of Schlemm Anterior chamber Lens Posterior chamber Pupillary aperture Ciliary muscle Figure 18-7 A, B
Figure 18-8
Figure 18-9
Figure 18-10
Figure 18-11
TABLE 18-1 Ophthalmic Anti-Infectives, Anti-Inflammatories, and Tear Supplements Category Example Action Topical antibacterial drugs (read labels bacitracin (Mycitracin, Trioptic-P, Works against gram + organisms; usually to determine if corticosteroids are used Vetropolycin, Neosporin Ophthalmic) found in combination with neomycin in these preparations) and polymyxin B polymyxin B (Mycitracin, Trioptic-P, Works against gram organisms; usually Vetropolycin, Neosporin Ophthalmic) used in combination with bacitracin and neomycin oxytetracycline (Terramycin ) Broad-spectrum antibiotic that is effective against Chlamydia sp.; may be used in combination with other drugs tetracycline (Achromycin ) Broad-spectrum antibiotic that is effective against Chlamydia sp. aminoglycosides Work against gentamicin (Gentocin, Garamycin, Staphylococcal and gram organisms, Genoptic ) including Pseudomonas sp. ; may be tobramycin (Tobrex ) formulated alone or with corticosteroids; neomycin (Mycitracin, Trioptic-P, neomycin is a broad-spectrum Vetropolycin, Neosporin Ophthalmic) antibiotic usually used in bacitracin and in combination with polymyxin B erythromycin (Ilotycine Ophthalmic ) Broad-spectrum antibiotic; usually used for gram + infections fluoroquinolones Broad-spectrum antibiotic ciprofloxacin (Ciloxan ) norfloxacin (Chibroxin ) ofloxacin (Ocuflox ) chloramphenicol (Bemacol, Chlorbiotic, Broad-spectrum antibiotics; handle with Chloricol, Vetrachloracin, Chlorasol ) care due to human side effects; cannot use in food-producing animals Topical antifungal drugs natamycin (Natacyn-Ophthalmic ) Works in treating mycotic keratitis (mainly Fusarium sp., Candida sp., Aspergillus sp.) Topical antiviral drugs idoxuridine (Stoxil ) Used to treat viral infections of the eye, trifluridine (Viroptic ) mainly in cats (ocular herpes). These vidarabine (Vir-A Ophthalmic ) drugs interrupt viral Table 18-1
Topical corticosteroid drugs prednisolone acetate drops Corticosteroids are used to treat (Pred Mild, Econopred ) inflammation of the conjunctiva, sclera, prednisolone sodium phosphate cornea, and anterior chamber. drops (generic brands) Penetration to the vitreous chamber and dexamethasone drops and ointment eyelids is poor. Corticosteroids delay (Decadron Phosphate, Maxidex ) healing and should not be used in triple antibiotic with hydrocortisone patients with corneal ulcers, fungal (Neobacimyx H, Trioptic-S, infections, or viral infections. Vetropolycin HC ) Table 18-1 Continued
TABLE 18-2 Otic Drugs Category Example Action Topical antibiotic otic drugs aminoglycosides: gentamicin (Otomax, Broad-spectrum antibiotics that are Getocin Otic Solution, Tri- Otic, usually combined with a corticosteroid, GentaVed Otic ); neomycin sulfate antifungal agent, and/or antiparasitic (Tresaderm, Panalog, Tritop ) agent. Neomycin sulfate products also contain thiostreptin, a gram + antibiotic; tympanic membrane should be intact when using this medication thiostreptin (Tresaderm, Panalog, Gram + antibiotic that is usually Tritop ) combined with a corticosteroid, antifungal agent, and/or antiparasitic agent chloramphenicol (Liquichlor, Broad-spectrum antibiotic usually Chlora-Otic ) combined with a corticosteroid and/or topical anesthetic. Do not use in foodproducing animals. Handle this drug with caution. fluoroquinolones: enrofloxacin Broad-spectrum antibiotic that is (Baytril Otic ) combined with silver sulfadiazine (has both antifungal and broad spectrum Table 18-2
antibacterial properties) Topical antiparasitic otic drugs thiabendazoles: (Tresaderm ) Used to treat ear mites in dogs and cats. Thiabendazole has antiparasitic and antifungal properties. Preparation may contain an antibiotic (such as neomycin) and a corticosteroid (such as dexamethasone) pyrethrins (Mita-Clear, Cerumite, Used to clear mite infestations of Aurimite ) the ear; treatment should continue for at least three weeks TABLE 18-2 Continued Category Example Action Topical antiparasitic otic drugs rotenone (Ear Miticide, Mitaplex-R ) Used to clear mite infestations of (cont.) the ear; treatment should continue for at least three weeks milbemycin oxime (MilbeMite ) Used to treat ear mite infestations in cats and kittens four weeks of age and older. Treatment consists of administering solution from one tube per ear as a single treatment. MilbeMite is available in a foil pouch that contains two tubes of solution (one tube for each ear). ivermectin: injectable (Ivomec ) Injectable treatment that is given SQ topical (Acarexx 0.01% suspension ) extra-label to treat ear mites in dogs and cats Otic solution is labeled for use in cats and kittens (more than four weeks of age) and is packaged in ampules selamectin (Revolution ) Once-monthly treatment for ear mites in cats; applied to dorsal cervical skin; (also protects against roundworms, hookworms, Table 18-2 Continued
TABLE 18-3 Opthalmic Drugs Covered in This Chapter Category Example Topical ophthalmic anesthetic proparacaine hydrochloride tetracaine hydrochloride Diagnostic stain fluorescein Miotic pilocarpine Mydriatic phenylephrine Mydriatic/Cycloplegic atropine homatropine tropicamide epinephrine Carbonic anhydrase inhibitor acetazolmide dichlorphenamide methazolamide Beta-adrenergic blocker timolol maleate betaxolol Osmotic diuretic mannitol glycerin Immunomodulator cyclosporine Topical antibacterial ophthalmic drug bacitracin neomycin polymyxin B oxytetracycline tetracycline aminoglycosides gentamicin tobramycin erythromycin fluoroquinolones ciprofloxacin norfloxacin ofloxacin chloramphenicol Table 18-3
TABLE 18-3 Continued Category Example Topical antifungal ophthalmic drug natamycin Topical antiviral ophthalmic drug idoxuridine trifluridine vidarabine Topical corticosteroid ophthalmic drug prednisolone acetate drops prednisolone sodium phosphate drops dexamethasone drops and ointment triple antibiotic with hydrocortisone neomycin and isoflupredone acetate gentamicin with betamethasone chloramphenicol and prednisolone Topical nonsteroidal anti-inflammatory flurbiprofen ophthalmic drug ketorolac tromethamine diclofenac Tear supplement artificial tears lubricants TABLE 18-4 Otic Drugs Covered in This Chapter Table 18-3 Continued
ophthalmic drug Tear supplement ketorolac tromethamine diclofenac artificial tears lubricants TABLE 18-4 Otic Drugs Covered in This Chapter Category Topical antibiotic otic drugs Topical antiparasitic otic drugs Topical otic antifungal agents Topical otic drying agents Topical otic cleansing agents Topical otic dewaxing agents Example gentamicin neomycin sulfate thiostreptin chloramphenicol enrofloxacin thiabendazole (neomycin/thiabendazole/ dexamethasone solution) pyrethrins rotenone milbemycin oxime ivermectin selamectin clotrimazole nystatin miconazole thiabendazole salicylic acid, acetic acid boric acid tannic acid antibiotics, antiseptics, and/or anesthetics/soothing containing agents used to clean the ear cerumen softeners or drying agents containing chemicals such as benzyl Table 18-4