Painless Acanthamoeba Keratitis with Normal Vision

Area of Science:

• Ophthalmology
• Infectious Diseases

Background:

• Contact lens wear is a significant risk factor for Acanthamoeba keratitis.
• Acanthamoeba keratitis can present with atypical symptoms, including the absence of pain.

Observation:

• A 15-year-old female soft contact lens wearer presented with a 2-week history of right eye redness and discomfort.
• Examination revealed diffuse radial keratoneuritis without epithelial defect in the right cornea.
• Corneal scraping confirmed the presence of Acanthamoeba trophozoites.

Findings:

• The patient was treated with propamidine isethionate and polyhexamethylene biguanide for 6 months.
• Despite the atypical indolent presentation, the patient experienced no ocular pain.
• Final visual acuity in the affected eye was 20/13 with a residual perineuritic scar.

Implications:

• This case underscores the importance of considering Acanthamoeba keratitis in contact lens wearers with corneal abnormalities, even in the absence of pain.
• Prompt microbiological work-up and appropriate amoebicidal therapy are crucial for successful management and visual preservation.
• Increased clinical awareness of indolent presentations of this sight-threatening infection is warranted.