Anterior Segment OCT Helpful to Assess Tick Embedded in Conjunctiva

A gloved hand holds a vial of juvenile deer ticks, or Ixodes scapularis, used in NIAID research conducted at the NIH Clinical Research Center. Deer ticks are also called blacklegged ticks and can transmit the pathogen that causes tickborne diseases such as babesiosis and Lyme disease. Credit: NIAID (Photo by: IMAGE POINT FR/NIH/NIAID/BSIP //Universal Images Group via Getty Images)
A case report shows a translucent tick attached to a patient’s eye.

Surgeons removed a tick that had embedded itself into the bulbar conjunctiva or a 66-year-old patient, a case report published in Photodiagnosis and Photodynamic Therapy describes. The team also outlined their management to prevent any serious secondary tick-borne infection, according to the paper. The patient, a farmer, scraped her right eye on a twig and experienced pain, redness, and itching. She noticed movement of something in the eye, and mucus discharge developed. The patient obtained a referral, and 2 days after the occurrence visited a clinic. 

A complete examination was performed, and during slit-lamp biomicroscopy, a translucent-bodied tick was discovered in her right eye, at the lower temporal bulbar conjunctiva. Swelling, hyperemia, and dilated episcleral vessels were noted. The organism was alive, with four pairs of legs intact. Clinicians used anterior segment optical coherence tomography (AS-OCT) to find how deeply the tick was embedded in conjunctival tissue. AS-OCT also revealed the sclera had not been infiltrated.

With local anesthesia, clinicians used annular excision starting 2 mm from the tick and removed arthropod-attached conjunctiva, including tenon capsules. The conjunctiva was sutured and treated with a course of topical antibiotics and corticosteroid drops. Patient follow-up involved blood tests after 10 days to rule out secondary infection, with test results coming back normal. Upon analysis, the tick was identified as a female larva, Ixodes nipponensis

The physicians, in this case, suggest that AS-OCT is helpful to ascertain the depth of a tick’s attachment and decide on the best surgical approach, as well as to have an image that assists in clean and complete removal of all tick parts.

Ocular tick infections are rare, and when they do occur, it is more often on the eyelid, according to the report. When a tick invades conjunctival tissue, it is not possible to first kill the organism with a chemical and then remove it with forceps, due to eye irritation. Squeezing a tick can press its infection-containing saliva into a human host’s blood vessels. Further, delays are not advised, because the risk for tick-borne disease transmission increases after 24 hours.

Few previous studies have focused on conjunctival tick infection, and this is the first report to use AS-OCT to evaluate how deeply a tick is positioned in the conjunctiva, the report explains. “The ophthalmic examination in daily practice may help in diagnosis, treatment options, and follow-up.” In such cases, including OCT in the examination may increase the reliability and effectiveness of treatment.


Kanar HS, Karaman S. Optical coherence tomography guided conjunctival tick infestation treatment: a case report. Photodiagnosis and Photodynamic Therapy. February 13, 2021. doi:10.1016/j.pdpdt.2021.102219.