Local anaesthesia in dentistry is very common procedure with low rates of adverse effects. Visual adverse effects are considered to be rare affecting around 1 in 1000 patients.

The aim of this review was to investigate the association between the occurrence of ocular adverse events and dental local anesthesia, the most plausible anatomic mechanisms, and the measures that offer patients a restitutio ad integrum.

Methods

Searches were conducted in the Medline, Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Embase, Embase Alert, and Science Citation Index Expanded databases. Case reports, case series, and previous clinical reviews in humans were considered. Two reviewers selected studies independently, no date restrictions were applied to the searches and studies in English or German were considered, with animal studies being excluded.

Results

• 66 studies (65 case reports, 1 case series) involving 89 patients were considered.
• The majority were female.
• Undefined ophthalmoplegia (weakness or paralysis of one or more extraocular muscles) was the most common adverse effect.
• Wide ranges of adverse effects were reported including: –
  • Amaurosis
  • Blindness
  • Diplopia
  • Endophthalmitis
  • Globe penetration
  • Horner syndrome
  • Impaired visual acuity (blurred vision)
  • Strabismus (convergent or divergent)
  • Loss of accommodation (cycloplegia)
  • Mydriasis (dilation of the pupil)
  • Ophthalmoplegia (internal or external, partial or total)
  • Ptosis
• 92% were transient – of these 25% took 6 hours to resolve.
• 8% caused permanent functional damage, either as vision deficit or anisocoria (two pupils are not of equal size).
• 46 were reported with maxillary injections, 42 with mandibular ones.
• Lidocaine was the most frequently involved anaesthetic agent.

Conclusions

The authors concluded:

This systematic review shows that ocular complications after administration of dental anesthesia are rather uncommon but may cause permanent damage to vision. Aspiration in two planes, consideration of the anatomic landmarks according to the technique implemented, and slow injections are highly recommended aspects for preventing such adverse events.

Comments

A good search has been conducted to identify papers for this review and the included papers are almost exclusively case reports as one might expect for rare side effects. While many randomised controlled have been conducted to assess different local anaesthetic agents none are included in the review. This may support the rarity of ocular side effects if none have been reported as these studies are typically between 50-200 patients in size. Alternatively it may be due to under reporting on side effects as is discussed by the authors. The high probability of under reporting means that while this review is helpful in summarising the range of ocular adverse effects the prevalence of around 1 in 1000 remains an approximation .

The NHS Choices website notes that medicines typically report whether each side effect is:

• Very common: more than 1 in 10 people are affected
• Common: between 1 in 10 and 1 in 100 people are affected
• Uncommon: between 1 in 100 and 1 in 1,000 people are affected
• Rare: between 1 in 1,000 and 1 in 10,000 people are affected
• Very rare: fewer than 1 in 10,000 people are affected

The review also includes a range of detailed anatomical figures and a discussion of the potential anatomical basis for the ophthalmic complications.

Links

Primary paper

Alamanos C, Raab P, Gamulescu A, Behr M. Ophthalmologic complications after administration of local anesthesia in dentistry: a systematic review. Oral Surg Oral Med Oral Pathol Oral Radiol. 2015 Nov 10. pii: S2212-4403(15)01286-9. doi: 10.1016/j.oooo.2015.10.023. [Epub ahead of print] Review. PubMed PMID: 26768073.

Other references

NHS Choices – What are side effects