THERAPEUTICS EX4 L2 (MEDCHEM EYES) (SUTARIYA)

Describe the pathophysiology of diabetic retinopathy

Damage to the small blood vessels of the retina -> blindness

Neovascularization in response to retinal hypoxia is the hallmark of proliferative diabetic retinopathy

What is panretinal laser photocoagulation?

Basically they use a laser to reduce oxygen demand in areas affected by neovascularization due to diabetic retinopathy

Used in diabetic retinopathy

T/F: Diabetic retinopathy is associated with scattered hemorrhages, yellow exudates, and neovascularization.

True

T/F: Radiation therapy can induce cataracts as a side effect.

True

In what patient populations does cataract formation occur more rapidly?

History of ocular trauma

Uveitis

Diabetes mellitus

Four causes of conjunctivitis? (pink eye)

Viral infection

Bacterial infection

Allergic reaction

Chemical irritation

Define conjunctivitis

Inflammation of the conjunctiva (the outermost layer of the eye and the inner surface of the eyelids)

Symptoms of conjunctivitis?

Red, watery eyes

Inflamed inner eyelids

Scratchy feeling in the eyes

Itchy eyes

Pus-like or watery discharge

Sensitivity to light

Swelling of the eyelid

Treatment options for allergic/irritant conjunctivitis? (three)

1. Avoid the cause of the irritation

2. Apply cool compresses to the affected area

3. Allergy eye drops (containing antihistaminic agent)

T/F: Melanoma is the most common primary tumor of the eye.

True

Complications associated with melanoma?

Photopsia

Enlarging scotoma

Loss of vision

Treatment for melanoma includes what?

Enucleation

Local resection

Irradiation

T/F: Breast and lung carcinomas have a special propensity to spread to the choroid or iris.

True

How does melanoma present on the choroid?

Elevated dark mass in the inferior temporal fundus

Limitations of topical drugs for the eye? (four)

Compliance

Corneal and conjunctival toxicity

Nasal mucosal toxicity

Systemic side effects from nasolacrimal absorption

Describe the absorption pattern or topical eye medications

Prompt, depends on formulation

Describe the limitations associated with subjconjunctival, sub-tenon's and retrobulbar injection medications for the eye

Local toxicity

Tissue injury

Globe perforation

Optic nerve trauma

Direct retinal drug toxicity with inadvertent globe perforation

Ocular muscle trauma

Prolonged drug effect

Sub-conjunctival, sub-tenon's, and retrobulbar injection medications for the eye are especially useful for? (three indications)

Anterior segment infections

Posterior uveitis

Cystoid macular edema

Describe the limitations associated with intraocular injection medications?

Corneal toxicity

Intraocular toxicity

Relatively short duration of action

Intraocular injections are especially useful for? (two indications)

Anterior segment surgery

Infections

Describe the limitation associated with intravitreal injections?

Retinal toxicity

Describe the absorption pattern of intravitreal injections?

Absorption circumvented

Immediate local effect

Potential sustained effect

Intravitreal injections are especially useful for? (two)

Endophthalmitis

Retinitis

T/F: Most ophthalmic drugs are delivered in solutions.

True

When do we use suspensions to administer ophthalmic drugs?

In drugs with limited solubility

Prolonged ophthalmic drug formulations include? (five)

Gels (i.e. pilocarpine 4% gel)

Ointments (for delivering antibiotics)

Solid inserts (i.e. ganciclovir, intravitreal implant)

Soft contact lenses

Collagen shields

T/F: Prolonging the time in the cul-de-sac facilitates drug absorption.

True

Ophthalmic medications administered via subconjunctival injection? (two)

5-fluororacil

Mitomycin

to retard fibroblast proliferation related to scarring after glaucoma surgery

Ophthalmic medications administered via intravitreal injection?

Antibiotics for endophthalmitis

Ophthalmic medications administered via intraocular insert?

Intraocular antivirals

Ophthalmic medications administered via implant?

Ganciclovir implant to treat cytomegalovirus retinitis in patients with AIDS

How do topical ophthalmic drugs undergo systemic distribution?

Primarily by nasal-mucosal absorption

Also by melanin binding of certain drugs

T/F: Esterase activates prodrugs.

True

Dipivefrin is a prodrug for what?

Epinephrine

Latanoprost is a prodrug for what?

Prostaglandin F2a

Loteprednol is a prodrug for what?

Prednisolone analogue

T/F: All ophthalmic medications can be absorbed into the systemic circulation.

True

Potential adverse effect of preservatives like benzalkonium chloride?

Punctate keratopathy

Toxic ulcerative keratopathy

What is dacryodenitis?

Infection of the lacrimal gland

Most common in children and young adults

Can be bacterial (S. aureus, strep)

Can be viral (Mumps, influenza herpes zoster)

Systemic antibiotics usually are indicated

What is dacryocystitis?

Infection of the lacrimal sac

Caused by S. aureus, strep species, Pseodomonas species

Clinical features of dacryocystitis?

Pain, swelling, redness over the lacrimal sacs

Tearing, crusting, fever

Treatment options for dacryocystitis?

Warm compresses

Nasal decongestants

Systemic and topical antibiotics

Hordeolum (or stye) is an infection of what glands?

Meibomian

Zeis

Moll

Describe blepharitis

Inflammation of the eyelid margins

Causes redness of the eyes, itching, and irritation of the eyelids

Describe keratitis

Corneal inflammation; can occur at any level of the cornea

T/F: Severe keratitis infections, with tissue loss (corneal ulcers) generally are treated more aggressively than infections without tissue loss (corneal infiltrates).

True

Describe endophthalmitis

Inflammation of the internal coats of the eye.

Dreaded complication of all intraocular surgeries.

Treatment of endophthalmitis generally involves what variety of treatment option?

Intravitreal injection of potent antibiotics; potential for vitrectomy, enucleation removal.

T/F: Endophthalmitis can cause retinal detachment and thereby vision loss.

True

Viral keratitis is most frequently caused by what two viruses?

Herpes simplex type I

Varicella zoster

Treatment for viral keratitis usually involves what oral agent?

Oral acyclovir

Describe herpes zoster ophthalmicus

Latent reactivation of a varicella zoster infection in the first division of the trigeminal cranial nerve

How is herpes zoster ophthalmicus generally treated?

Systemic acyclovir, valacyclovir, and famciclovir

Describe viral retinitis

Caused by herpes simplex virus, cytomegalovirus (CMV), adenovirus, and varicella zoster virus

T/F: Viral retinitis can cause necrosis, hemorrhage of the retina.

True

Which intravitreal agent is used to treat viral retinitis?

Ganciclovir

T/F: Natamycin is the only commercially available antifungal for ophthalmic use.

True

T/F: All antifungal agents are used for fungal keratitis and endopthalmitis.

True

Describe uveitis

Inflammation of the middle layer of the eye (termed the uvea)

Inflammation of the uvea is termed what?

Iridocyclitis

Causes of uveitis?

Protozoal infections like acanthamoeba, toxoplasma gondii

T/F: Protozoan keratitis can occur via acanthamoeba infection in lens wearers.

True

Treatment options for uveitis?

Antibiotics like polymyxin B, bacitracin, neomycin

Sometimes antifungals, i.e. clotrimazole, miconazole, ketoconazole

Glucocorticoids formulated for topical administration to the eye? (six)

Dexamethasone

Prednisolone

Fluorometholone

Loteprednol

Rimexolone

Difluprednate

Topical corticosteroids are used in managing significant .... ? (five indications)

Ocular allergy

External eye inflammatory diseases

Ocular cicatricial pemphigoid

Anterior uveitis

Postoperative inflammation

Toxic effects of ophthalmic glucocorticosteroids?

Development of posterior subcapsular cataracts

Secondary infections

Secondary open-angle glaucoma

Describe the significance of family history of open-angle glaucoma as it pertains to IOP increase in patients taking glucocorticosteroids

Only 5% of patients w/o a family history of open-angle glaucoma only experience a clinically significant increase in IOP

With a positive family history, though, 90% experience an increase in IOP

What are the five topical NSAIDs approved for ocular use?

Flurbiprofen

Ketorolac

Diclofenac

Bromfenac

Nepafenac

Cyclosporine emulsion is typically used for what indication?

Dry eye

What drug is used to induce mydriasis?

Atropine

What drug class is used to induce miosis? Examples?

A2 adrenergic agonists

Carbachol, acetylcholine

Describe corneal band keratopathy

Characterized by an opacification of the superficial cornea within the interpalpebral fissure due to a deposition of calcium phosphate in Bowman layer and the superficial corneal stroma.

What is used to reverse corneal band keratopathy?

Sodium edetate

MOA of botulinum toxin type A?

Prevents acetylcholine release at the neuromuscular junction

Causes a temporary paralysis of the locally injected muscles

What is botulinum toxin type A useful for (ophthalmic indications)?

Strabismus

Blepharospasm

What is administered (and how) for pain associated with a blind and painful eye?

Retrobulbar injection of absolute of 95% ethanol or chlorpromazine

What three drugs have toxic side effects on the retina?

Hydroxychloroquine

Chloroquine

Sildenafil

What three drugs have toxic side effects on the optic nerve?

Ethambutol

Chloramphenicol

Rifampin

What is hypopyon?

Pus in the eye

T/F: Isotretinoin cause dry eye.

True

Amiodarone is most commonly associated with what ophthalmic side effect?

Cornea verticillata

What is cornea verticillata?

Pigmentation in the epithelium of the cornea

Fine tan/brown pigment

Medications which can cause cornea verticillata? (five)

Indomethacin

Atovaquone

Chloroquine

Hydroxychloroquine

Amiodarone

Phenothiazines are associated with what ophthalmic side effect?

Brown pigment deposits in cornea, conjunctiva, and eyelids

Gold is associated with what ophthalmic side effect?

Gold deposition in the cornea and conjunctiva, termed chrysiasis and are gold to violet in color

Three types of agents used to assist in ocular examination?

Mydriatic agents

Topical anesthetics

Dye to evaluate corneal surface integrity

The types of agents used to assist in intraocular surgery?

Mydriatic agents

Miotic agents

Topical and local anesthetics

Cocaine, pilocarpine are used to diagnose what?

Anisocoria (unequal pupil size)

Agents used for diagnosis of excessive tearing and surface problems of cornea and conjunctiva?

Fluorescein, rose bengal, lissamine grean

Dyes used to reveal aqueous humor leakage

Side effects of fluorescien?

Nausea

Serious allergic reactions

Neon pee

Fluorexon is used when fluorescein is contraindicated (and when soft contact lenses are in place)

What is verteporfin?

Photosensitizer used to eliminate abnormal blood vessels in the eye associated with wet macular degeneration

Nutritional vitamin A deficiency can lead to what?

Xeropthalmia

What is xerophthalmia?

Nyctalopia (night blindness)

Xerosis

Keratomalacia (corneal thinning)

Osmotic drugs for ocular use include? (three)

Glycerin

Mannitol

Hypertonic saline

Therapeutic uses of osmotic drugs for ocular use?

Intraocular pressure of glaucoma

Corneal edema