From the FDA Drug Label
Central Nervous System CNS manifestations are excitatory and/or depressant and may be characterized by ... blurred or double vision, ... sensations of heat, cold or numbness, ... Small doses of local anesthetics injected into the head and neck area, including retrobulbar, dental and stellate ganglion blocks, may produce adverse reactions similar to systemic toxicity seen with unintentional intravascular injections of larger doses ... Confusion, convulsions, respiratory depression and/or respiratory arrest, and cardiovascular stimulation or depression have been reported. These reactions may be due to intra-arterial injection of the local anesthetic with retrograde flow to the cerebral circulation. In addition, ... toxic blood concentrations depress cardiac conduction and excitability, which may lead to ... sometimes resulting in fatalities ... restlessness, anxiety, tinnitus, dizziness, blurred vision, tremors, depression, or drowsiness may be early warning signs of central nervous system toxicity. Small doses of local anesthetics injected in dental blocks may produce adverse reactions similar to systemic toxicity seen with unintentional intravascular injections of larger doses.
Dental anesthesia can cause eye numbness and vision problems.
- The possible effects include blurred vision and double vision.
- Numbness can also occur due to the effects of the anesthetic on the central nervous system.
- These effects are more likely to occur with intra-arterial injection or high plasma levels of the anesthetic.
- Constant monitoring of the patient's vital signs and state of consciousness is necessary after each local anesthetic injection to quickly identify any potential issues 1, 1, 2.
From the Research
Dental anesthesia can occasionally cause temporary eye numbness or minor vision changes, particularly when administered in the upper jaw, but true vision problems are extremely rare. This occurs because dental nerve blocks, especially those targeting the maxillary branch of the trigeminal nerve (such as posterior superior alveolar nerve blocks), can spread to nearby structures. The anesthetic solution may diffuse to adjacent areas, affecting branches that supply sensation to the eye region, including the infraorbital nerve. Patients might experience numbness around the lower eyelid, cheek, or side of the nose, and occasionally report blurred vision or a sensation of eye heaviness.
These effects are almost always temporary and resolve as the anesthetic wears off, typically within 1-4 hours depending on the type of anesthetic used (lidocaine lasting 1-2 hours, bupivacaine up to 4-8 hours) 3. According to a systematic review published in 2016, ocular complications as a result of dental local anesthesia may be seen as rare occurrences with usually low intensity, and only 8% of the complications caused permanent functional damage 4.
Some key points to consider:
- The most commonly used local anesthetic agents in dentistry, such as lidocaine, have a low incidence of adverse effects and allergic reactions 5.
- Articaine is considered a good choice of local anesthetic in contemporary dentistry due to its high anesthetic potency and low systemic toxicity 6.
- To minimize the risk of adverse effects, it is essential to follow the recommended dosage and perform aspiration tests before administering local anesthetics 6.
If vision changes persist beyond the expected duration of the anesthetic or are accompanied by severe symptoms like significant vision loss or eye pain, immediate medical attention should be sought as this could indicate a more serious complication.