38.3: Ocular Anesthetics and Lubricants
By the end of this section, you should be able to:
- 38.3.1 Identify the characteristics of ocular anesthetic and lubricant drugs used to treat eye disorders.
- 38.3.2 Explain the indications, actions, adverse reactions, and interactions of ocular anesthetic and lubricant drugs used to treat eye disorders.
- 38.3.3 Describe the nursing implications of ocular anesthetic and lubricant drugs used to treat eye disorders.
- 38.3.4 Explain the client education related to ocular anesthetic and lubricant drugs used to treat eye disorders.
Ocular Anesthetics
Local anesthesia blocks nerve conduction of sensory impulses and motor impulses from the periphery to the CNS. Sodium channels are blocked to inhibit increases in permeability of the nerve membrane required for an action potential. Because the initiation and propagation of action potentials is deterred, sensation cannot be transmitted from the source of stimulation to the brain.
Several ophthalmic procedures require adequate local anesthesia of the eyes. Some of these procedures include measurement of intraocular pressure, removal of foreign bodies, repairing corneal damage with sutures, Lasik surgery, conjunctival scraping, and gonioscopic examination to detect signs of glaucoma. Prolonged use of a topical ocular anesthetic may produce permanent corneal opacification with accompanying loss of vision (Sharifi et al., 2022).
Clinical Tip
Identifying Names of Local Anesthetics
All ocular anesthetic medications end in the suffix “caine.” This is useful to know when the nurse does not recognize the drug’s name but can identify it is an anesthetic based on its suffix.
Proparacaine HCL
Proparacaine is a topical anesthetic used prior to surgical operations such as cataract extraction. This drug has a rapid onset with a short duration; therefore, it is usually given in repeated doses. Also, clients should not touch the eye while it is numb to avoid accidental injury due to the insensitivity of the eye (Mayo Clinic, 2023b).
Tetracaine HCL
This drug has a slow onset with a long duration of action. It may only need to be administered once. Clients should not touch the eye while it is numb to avoid accidental injury due to the insensitivity of the eye (Mayo Clinic, 2023b).
Table 38.10 lists common ocular anesthetics and typical routes and dosing for adult clients.
| Drug | Routes and Dosage Ranges |
|---|---|
|
Proparacaine
( Alcaine , Ocu-Caine ) |
0.5% ophthalmic solution:
For ophthalmic anesthesia: 1–2 drops in affected eye(s) before the procedure. For anesthesia in short corneal and conjunctival procedures: 1 drop in affected eye(s) every 5–10 minutes for 5–7 doses. |
|
Tetracaine
( Pontocaine , Ametop ) |
0.5% or 1% tetracaine hydrochloride solution:
1–2 drops in eye(s) as needed. Doses vary depending on ophthalmic procedure: Corneal foreign body or suture removal: 1–2 drops in affected eye(s) every 5–10 minutes for 1–3 doses. Brief ophthalmic anesthesia (tonometry or short corneal/conjunctival procedures): 1–2 drops in eye(s) prior to starting the procedure. Prolonged ophthalmic anesthesia (e.g., cataract extraction or other extended procedures): 1–2 drops in affected eye(s) every 5–10 minutes for 3–5 doses. |
Adverse Effects and Contraindications
Local effects of stinging, burning, or redness can occur. Prolonged use or misuse can lead to corneal epithelial toxicity, resulting in opacity of the cornea with varying levels of vision loss. With the use of proparacaine, a rare, severe, immediate, apparently hyperallergic corneal reaction may occur, characterized by acute, intense, and diffuse epithelial keratitis; a gray, ground-glass appearance; sloughing of necrotic epithelium; corneal filaments (strands composed of degenerated epithelial cells and mucus that adhere to the cornea); and iritis (inflammation of the iris) with descemetitis (membrane inflammation) (DailyMed, Proparacaine , 2023).
Table 38.11 is a drug prototype table for ocular anesthetics featuring proparacaine. It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Ocular anesthetic Mechanism of Action Temporarily blocks sodium ion channels, which inhibits increases in permeability of the nerve membrane, thus preventing the initiation and conduction of action potentials, which prevents the transmission of sensation from the area being stimulated to the brain |
Drug Dosage
0.5% ophthalmic solution: For ophthalmic anesthesia: 1–2 drops in the affected eye(s) before the procedure. For anesthesia in short corneal and conjunctival procedures: 1 drop in the affected eye(s) every 5–10 minutes for 5–7 doses. |
|
Indications
For procedures in which a topical ophthalmic anesthetic is indicated Therapeutic Effects Promotes anesthesia (numbing) |
Drug Interactions
No significant interactions Food Interactions No significant interactions |
|
Adverse Effects
Transient stinging or burning Conjunctival erythema (redness) Ocular pain/discomfort Possible vision loss due to corneal opacity Diffuse epithelial keratitis |
Contraindications
Hypersensitivity to any of the ingredients |
Nursing Implications
The nurse should do the following for clients who are taking ocular anesthetics:
- Conduct a thorough preoperative assessment including past experience with ocular surgery, cardiac and respiratory issues, pain tolerance, past medical history, allergies, and medication list, including use of anticoagulants.
- Perform postoperative assessment as prescribed. Be especially aware of pain level because this indicates the anesthesia is wearing off.
- Ensure there is adequate lighting and lack of clutter to promote client safety.
- Frequently remind clients not to touch their eyes while the eye is still numb to avoid ocular injuries.
- Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.
Client Teaching Guidelines
The client taking an ocular anesthetic should:
- Tell the health care provider about a history of falls, ambulation deficits, and the use of ambulatory aids. Ocular anesthetic drops can alter perception and potentially lead to a fall.
- Inform the health care provider if there is a progressive deterioration in vision.
- Let the nurse know if they are experiencing any ocular pain.
The client taking an ocular anesthetic should not:
- Touch their eyes while still numb from ocular anesthetics to avoid accidental injury due to insensitivity of the eye.
- Attempt to ambulate independently if vision is unclear.
Ocular Lubricants
Eye lubricants are used to temporarily relieve burning, irritation, and discomfort caused by dry eyes. They serve as a protector from further eye irritation. These products come in various forms: gel, ointment, emulsion, and solution. Most of these can be found over-the-counter (OTC); therefore, it is important clients follow the printed instructions. Some ophthalmic lubricants are antimicrobial and reduce the risk of infection. Others constrict blood vessels and reduce redness in the eye; still others contain zinc sulfate, an astringent that dries the mucus and relieves eye irritation.
Artificial tears and white petrolatum/mineral oil are more similar than different (Khan, n.d.). Artificial tears come in solution form. The active ingredients are glycerin and propylene glycol, which are clear isotonic solutions and should not be used if the color changes or the solution becomes cloudy. White petrolatum/mineral oil is available as an ointment. The active ingredients are mineral oil and white petrolatum.
Table 38.12 lists common ocular lubricants and typical routes and dosing for adult clients.
| Drug | Routes and Dosage Ranges |
|---|---|
|
Artificial tears
( LubriTears , Systane ) |
1–2 drops in affected eye(s) on an as-needed basis for dry or irritated eyes. |
|
White petrolatum/mineral oil
( Lacri-Lube ) |
¼ inch of ointment to inside of eyelid as needed. |
Adverse Effects and Contraindications
The adverse effects of ocular lubricants include ocular burning, itchy watery eyes, blurred vision, and sensitivity to light (Drugs.com, 2023).
Table 38.13 is a drug prototype table for ocular lubricants featuring white petrolatum/mineral oil. It lists drug class, mechanism of action, adult dosage, indications, therapeutic effects, drug and food interactions, adverse effects, and contraindications.
|
Drug Class
Ocular lubricant Mechanism of Action Reduces the osmolarity of the tear film and/or dilutes inflammatory substances |
Drug Dosage
¼ inch of ointment to inside of eyelid as needed. |
|
Indications
For the temporary relief of burning, irritation, and discomfort due to dryness of the eye or exposure to wind or sun As a protectant against further irritation Therapeutic Effects Replaces missing tear constituents for relief of burning and irritation |
Drug Interactions
No significant interactions Food Interactions No significant interactions |
|
Adverse Effects
Blurred vision Stickiness of eyelashes from ointment Stinging Eye pain Eye redness |
Contraindications
Allergy to any inactive ingredient |
Nursing Implications
The nurse should do the following for clients who are taking ocular lubricants:
- For the client who is intubated and is not spontaneously blinking, who is unconscious, or who is unable to close their eyes and blink, the nurse must assess the eye frequently and use a damp cloth to remove prior lubricant to avoid buildup or crusting.
- Observe the client’s entire face and cleanse the areas around the eyes and face to promote hygiene and avoid infection.
- Evaluate therapeutic effectiveness of medication and observe for hypersensitivity reactions such as rash, dizziness, difficulty breathing, or itching or swelling of the face, tongue, or throat.
- Provide client teaching regarding the drug and when to call the health care provider. See below for client teaching guidelines.
Client Teaching Guidelines
The client taking an ocular lubricant should:
- Be careful not to contaminate the tip of the dispenser because this may cause an eye infection.
- Notify the health care provider if symptoms are not improving or are getting worse.
- Use appropriate technique when instilling the lubricant.
The client taking an ocular lubricant should not:
- Continue using the medication if they experience eye pain, vision changes, continued redness, or irritation of the eyes.
- Double the dose if they missed one (Cleveland Clinic, 2023a).
- Drive or engage in hazardous activity until vision has cleared.