Expanded scopes of practice in recent years means ODs across the country have authority to prescribe oral medications to treat various eye conditions, which in turn allows for enhanced quality of care. But it’s vital to understand indications, mechanisms of action, and potential side effects of oral medications.
You must also make sure you’re prescribing within your scope, as authority varies a bit by state. With that in mind, let’s take a look at the latest information and resources on prescribing oral medications to treat optometric issues.
Before initiating oral meds, a complete ocular and systemic history is crucial. This includes detailed knowledge of any other medications the patient is taking and whether the individual has any relevant drug allergies. Also, it is important to document his or her general health status — particularly liver and kidney function. Remember that proper liver function is critical for the metabolism of oral medications, and kidney function is integral to drug excretion.
A practical pointer: When encountering patients with extensive medication lists and multiple drug allergies, it may be helpful to ask them which agents they’ve used in the past for pain management or certain infections. We have several of these patients in our practice. Over time, many of them have learned which pain medications, for example, they can take without difficulty. (Source: When a Drop Isn’t Enough)
Infection Treatment
Antibiotics are the most commonly prescribed oral medication in optometry and are used when a bacterial infection is severe, widespread, or involves deeper ocular structures. Conditions like blepharitis, dacryocystitis, and preseptal cellulitis often require oral antibiotics:
Some ocular infections should be treated with an oral antibacterial agent as standard of care, including hordeolum, preseptal cellulitis and dacryocystitis. Oral antibacterial agents provide high systemic levels, which results in better penetration of the agent into the lacrimal apparatus and surrounding tissues. (Source: Antibiotics in Eye Care: A Balancing Act)
Read more: The OD’s Guide to Systemic and Topical Antibiotics with Cheat Sheet, Eyes on Eyecare
Inflammation Management
Oral anti-inflammatory medications, including corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs), tend to be used for conditions such as uveitis, scleritis, and other inflammatory disorders that may not respond fully to topical treatments.
Read more: Know the Ins and Outs of Oral Steroids, Review of Optometry
Glaucoma Treatment
Certain oral medications, such as carbonic anhydrase inhibitors (CAIs), help lower IOP in acute glaucoma attacks or act as adjuncts to topical medications when eye pressure is not well-controlled.
Systemic medications for intraocular pressure control are typically reserved for cases in which a significant temporary drop in IOP is required that cannot be achieved by any other means.
Oral preparations are most commonly used in cases of acute angle-closure glaucoma or surrounding intraocular surgery, in which substantial pressure spikes may arise. (Source: Everything You Need to Know About Oral Glaucoma Medications)
A Note About Cannabis
While not a mainstream treatment — and needing significant further research — cannabis has been explored in glaucoma treatment primarily due to its effect on IOP. THC, the psychoactive compound in cannabis, is responsible for this pressure-lowering effect. But the effect is short-lived (typically 3 – 4 hours), making it impractical for treatment compared to conventional medications like prostaglandin analogs or beta-blockers, which can control IOP for longer periods with fewer doses.
Essentially, to maintain purported benefits, cannabis would need to be used frequently, which could lead to impaired cognition, dizziness, etc. Not exactly practical or safe.
Allergy Relief
For severe allergic reactions that affect the eyes, oral antihistamines or systemic steroids may reduce symptoms like swelling, redness, and itchiness. Of course, it’s important to consider that oral antihistamines can effectively dry up mucous membranes and cause patients to experience more redness, itchiness, or dry eyes. Decreased tear production from dry eyes means allergens can concentrate in the eye, causing further irritation.
Read more: The Allergic Eye: Recommendations About Pharmacotherapy and Recent Therapeutic Agents, Allergy and Clinical Immunology
Dry Eye Management
In some cases, oral meds such as tetracycline-based antibiotics, are used to manage chronic dry eye by improving tear film stability or reducing inflammation in the meibomian glands.
Read more:
Dry Eye Disease (Keratoconjunctivitis Sicca) Medication, Medscape
How — And Why — to Choose Dry Eye Drugs, Review of Optometry
Inversely, here’s a handy primer on oral medications that can cause dry eye in your patients. Save it as a reference when inquiring about patient history during exams.
Herpes Simplex and Zoster Infections
Oral antivirals like acyclovir or valacyclovir are used to manage viral infections like herpes simplex keratitis or herpes zoster ophthalmicus. Oral antiviral medications can help decrease both the incidence and severity of ocular complications and are generally well tolerated by patients.
Systemic Conditions Affecting the Eyes
Oral medications can also be used to treat systemic diseases with ocular manifestations, such as diabetes (which can lead to diabetic retinopathy) or autoimmune diseases that cause inflammation in the eyes.
Read more: APX3330 “Promising” Oral Treatment Option for Slowing Progression of Diabetic Retinopathy
Controlled Substances
Take a look at this map — Optometrist Prescription of Controlled Substances by State — to see optometrist authority to prescribe certain classifications of controlled substances by state or territory.
Note: As of June 2023, the DEA requires a new one-time training requirement for all DEA-registered practitioners on the treatment and management of patients with opioid or other substance use disorders. (Source: DEA Numbers and Optometry)
Best Practices
As mentioned up top, it’s important to set yourself up for success during the initial exam:
One key to successfully prescribing oral medications to your patients is to obtain a comprehensive medical history, detailed medication review (including supplements and vitamins), allergy history (including reaction) and review of systems … A drug interaction check program or app is also an important step to confirm that the proposed medication will not introduce a potentially harmful effect due to interaction with any current medications or supplements. (Source: Prescribe Oral Meds Like a Pro)
You should also consider effects on pregnancy and lactation, birth control, fertility, etc.
This article was compiled using information from the sources linked above and the following comprehensive resources for prescribing oral medications:
Safe and Savvy Prescribing of Oral Pharmaceuticals, Review of Optometry
Pharmaceutical Management with Ophthalmic Orals, ODReference
The Dos and Don’ts of Oral Medication, Review Education Group
The Role of Oral Medications in Optometry, Woo University
