Although it may not be a shock for many regular contact lens users that wearing contacts make their eyes prone to certain eye complications, but they may not know that these complications can rapidly worsen and can even lead to blindness.
A case of a 41-year-old female with ophthalmologic complications due to contact lens is an example for many. She presented to the clinic with complaints of blurred vision, photosensitivity, and fluctuating, intermittent pain in her left eye for the past two months. She used to wear her monthly disposable soft contacts uninterruptedly, even while swimming and taking a shower.
On examination, the patient was unable to keep her left eye open which had redness in the conjunctiva. Visual acuity in her right and left eye was 20/20 and 20/200, respectively.
On Slit-lamp examination, an infiltrate was seen in the left eye which was in the shape of a large ring. Corneal haze and a defect in the fluorescein dye uptake was also observed.
A definitive diagnosis of Acanthamoeba keratitis was made when Acanthamoeba polyphaga grew in the cultures from corneal scrapings.
Contact lenses have a worldwide influence on the incidence of ulcerative keratitis. Acanthamoeba keratitis was once a very rare disease, but with the popularity of contacts, the occurrence of this vision-threatening infection has substantially increased.
Acanthamoeba keratitis is the nightmare for any contact lens user.
There are multiple causative factors that govern the contact lens-related problems, such as the material of the lens, care of the contacts by the user, compliance of the user, overwearing, not removing the lenses during sleeping, lens case hygiene and frequency of changing contact lenses. Any of the factors can lead to the growth of Acanthamoeba, which is a free-living amoeba, commonly found in soil, lakes, oceans, pools, tap water, ventilation units, heating units, and also in the contact lens fluid.
Contact lenses, although a major source, but are not the only risk factor. Exposure to contaminated water and trauma to the eye can also let Acanthamoeba enter the eye.
Signs and symptoms of Acanthamoeba eye infection may include:
- Intense pain
- Photophobia ( sensitivity to light)
- Reduced vision
- Redness
- Gritty (foreign body) sensation
- Eye discharge and tearing
- Infiltrates in the stroma and epithelium
- Pseudodendrites
- Corneal perforation
- Satellite lesions
- Keratitis, scleritis, and anterior uveitis
- Secondary glaucoma
To avoid a wide array of complications, early diagnosis and prompt treatment play a vital role in preserving vision. Although its diagnosis is difficult to be made, a prompt and aggressive management approach is crucial, because once the amoeba digs deeper, the chances of successful treatment lower significantly.
No single drug has been effective in
eliminating Acanthamoeba. Current practice includes topical antimicrobials and
topical chlorhexidine. The role
of steroid remains controversial.
The surgical procedure of choice is keratoplasty.
One of the leading reason for a late diagnosis in contact lens users is that they are habitual of mild irritation, which leads to the delay in seeking professional help.
The patient in the discussion here was prescribed topical polihexanide and propamidine isethionate, which resolved the infection but couldn’t restore the vision in her left eye due to a central, dense corneal scar and cataract. Deep anterior lamellar keratoplasty was performed on her left eye after twelve months of the initial presentation, which relieved the discomfort and resulted in a postoperative visual acuity of 20/80 in her left eye.
Bottom line:
Though contact lenses serve dual purposes of correcting vision and cosmesis, it is highly imperative to follow the ‘contact lens hygiene and care’ rules, such as to wash hands before touching contacts, avoid sleeping with the contact lenses, use fresh sterile solution for the lenses, etc.
Immediately remove contact lenses if any discomfort, redness or irritation is felt. Don’t think twice. The worth of eyes is incomparable to a pair of contact lenses!
REFERENCES:
Lorenzo-Morales, J., Khan, N. A., & Walochnik, J. (2015). An update on Acanthamoeba keratitis: diagnosis, pathogenesis and treatment. Parasite (Paris, France), 22, 10. https://doi.org/10.1051/parasite/2015010
Lanxing Fu, M. C. (2019, July 18). Acanthamoeba Keratitis. Retrieved from The New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMicm1817678
Page MA, Mathers WD. Acanthamoeba keratitis: a 12-year experience covering a wide spectrum of presentations, diagnoses, and outcomes.External J Ophthalmol. 2013;670242.
https://www.aoa.org/patients-and-public/eye-and-vision-problems/glossary-of-eye-and-vision-conditions/acanthamoeba
