by Juan Ding, OD, PhD
Walk in patients are fun, especially on a Friday.
27 year old female walked in our open access clinic today, reporting seeing floaters for 1 month in the left eye which bothered her. Otherwise she had no change in vision and no pain. She did not see any flashes. She saw 20/15 each eye and had normal eye pressures. Right eye was completely normal. The left eye had numerous deposits on the back side of the cornea, called KPs, and a few cells floating in the anterior chamber. There were numerous cells in the vitreous. There were two black scars in the retina close to the macula, and a fluffy white lesion with smaller (satellite) white lesions surrounding it. The retinal blood vessels and other parts of the retina, as well as the optic nerve, looked normal (photo below).
Figure 1. Fundus image showing inactive scars (arrow heads) and an active lesion (arrow).
What is your diagnosis?
On questioning, she admitted to be told to have toxoplasmosis in her left eye in 2015 when she had an eye exam for doing refractive surgery. She was told it was stable before and after her photorefractive keratectomy (PRK) surgery.
Apparently toxoplasmosis has reactivated in her left eye. “Most of the recurrences occur in the second and third decades of life in immunocompetent individuals, and may be triggered by stress or other factors.” according to an American Academy of Ophthalmology article (https://www.aao.org/current-insight/management-of-ocular-toxoplasmosis).
Toxoplasmosis is acquired by eating raw or undercooked meat, vegetables or milk products, or by coming into contact with infected cat litterbox or sandboxes, but contaminated water source has also been linked. Toxoplasmosis can also be congenital, when infection in pregnant women transfer to the fetus.
The treatment for ocular toxoplasmosis can be observation only if the lesion is peripheral and small, as in healthy people this will usually resolve without affecting vision. But if it threatens vision, such as when lesion is close to the macula or optic nerve is involved, or macular edema is present, systemic antibiotics and corticosteroid treatment are usually needed. Topical steroid is also used in the case of anterior uveitis (such as in our patient).
So not all floaters are age-related normal phenomenon.