Ocular Pharmacology, Other Meds, and Their Effects on Vision

Healthy Sight Counseling is

is a standard of care that all ECP’s should practice because its ramifications can have a significant impact on patient outcomes and overall ocular health.

Why is it important to tell your eye doctor about taking medications?

more than 33% of respondents were unaware that their medications could have any side effects on their eyes.

Factors that influence local drug penetration include:

Drug concentration and solubility, viscosity, lipid solubility

Drug concentration and solubility

The higher the concentration, the better the penetration

Viscosity

The addition of methylcellulose and polyvinyl alcohol increases drug penetration by increasing the contact time with the cornea and altering the corneal epithelium

Lipid Solubility

because of the lipid-rich environment of the epithelial cell membranes, the higher lipid solubility, the more penetration.

Time-release system

the medication is administered to the patient but the drug releases its effects over a short period of time.

Most drugs are systemic

meaning that they are delivered throughout the entire body

Disadvantage of systemic treatment

the effects of the medication can be the cause of problems in locations of the body that did not have any problems - side effect

The possibility of side effects increases when

more than one medication is used

Dry Eye

Benadryl, Chor-trimeton, Claritin, Zyrtec, Amitriptyline, Accutane, Aspirin, Ibuprofen, Niacin

Light Sensitivity

Cortisone, Lopressor, Inderal, Coreg, Norvasc, Tenormin, Porcardia, Lasix, Methotrexate, Amitriptyline, Accutane, Viagra, Cialis, Aspirin, Ibuprofen, St.John’s Wart

Enlarged Pupils (mydriasis)

Prozac, Ritalin, Dexedrine, Ami, Atropine, Gl

Glare Phenomenon

Antimicrobial agents

Double Vision

Tenormin, Lopressor, Xanax, Valium, Topomax, Aspirin, Ibuprofen

The adverse ocular effects of medications can be divided into three categories

Quantity of vision, quality of vision, and ocular disorders

Quantity of Vision refers to

symptoms that note a vision change. examples of these symptoms include blurred vision, altered refractive status, or accommodative dysfunction

Classes of drugs that blur vision or alter refractive/accommodative state

• Antihistamines

• Anticonvulsants

• Antidepressants

  • antiestrogen, alkylating, antineoplastic antibiotic agents

• Bisphosphonates

• Cardiac agents

• Diurectics

• Erectile Dsyfunction Agents

• Topiramate

Quality of Vision

refers to effects that cause alteration of vision

Quality of Vision Effects

• Increased light sensitivity

• mydriatic drugs

Photophobia

increased light sensitivity

Mydriatic drugs

dilate pupils, which increases the amount of light entering the eyes. allows for more UV radiation to enter the eye

Miotics

perform the opposite to mydriatics.

They constrict the pupils, decreasing the amount of light entering the eyes and impairing the light-to-dark adaptation

depth perception also becomes an effect of miotic drugs

Classes of drugs that may cause Photosensitivity

• Antiarrhymics

• Antibiotic

• Anticholinergics

• Antidepressants

• Antipsychotics

• Cardiac agents

• CNS stimulants

• Folic acid antagonistics

• Herbs, such as St.Johns wart

• NSAIDS

• Oral Contraceptives

• Tranquilizers

• Retinoids

• diuerectics

Ocular Disorders

Medications in this group contribute to disorders such as cataracts, keratopathies, maculaopathies, optic neuropathies, glaucoma.

Conditions in this category are long term medical conditions and pose a much greater risk to vision. 

Antiarrhythmic agents

Keratopathy, optic neuropathy

Antineoplastic agents

keratitis, scleritis, color blindness, retinopathy, papilledema, maculopathy, dry eyes, cataracts, glaucoma, optic neuritis, blepharitis

Antipsychotics

cataracts, keratopathy

Bisphosphonates

conjunctivitis, scleritis, uveitis

Corticosteroids

cataracts, galucoma

Dermatologic agentss

keratopathy, dry eye, optic neuritis, night blindness, blepharoconjunctivitis H

HIV-AIDS

night blindness, retinal detachments, glaucoma, cataracts, maculopathy, retinopathy, optic neuritis, conjunctivits

It is important to note that the cats of quality of vision and development of ocular disorders have something in common

The common denominator in both categories is the effect of UV radiation. Medications that dilate the pupil allow more UV radiation into the eye increasing the exposure level.

Antireflective coated lenses

will increase light transmission through a lens and knock out lens reflections up to 99% in premium coatings. reduces glare

Photochromic lenses

provide relief from 2 types of glare, discomforting glare and disabling glare. Both of these benefit from light regulating property of the lenses.

Blinding glare is best addressed with

polarized lenses because they block reflections off shiny surfaces like water or a car hood.

Medications used during the eye exam

Two groups of dilating drops:

• Parasympathetic antagonists (parasympatholytics): act by paralyzing the iris sphincter muscle.

  • will make the pupil larger and paralyze the muscle involved in the focusing of the lens (accomodation)

• Sympathetic agonists (sympathomimetics): act by stimulating the iris dilator muscle.