Abstract
Purpose: :
Acanthamoeba causes a vision-threatening infection of the cornea, maily in contact lens wearers. In patients with corneal pseudodendrites, radial keratoneuritis and ring infiltrates, Acanthamoeba keratitis (AK) must be considered in the differential diagnosis. Clinically effective treatment of AK includes a combination of a biguanide such as chlorhexidine or polyhexanethylene biguanide (PHMB) and a diamidine such as propamidine or hexamidine. It has been suggested in the literature that cataract and iris atrophy can occur during AK treatment. The purpose of this study is to review cases of AK followed at the Department of Ophthalmology, UNIFESP, and to estimate the incidence and risk factors for the development of mydriasis, cataract and glaucoma, and associated complications.
Methods: :
Case series of AK patients that were examined from 1991 to 2010. Clinical findings, risk factors, and complications were reviewed. Ocular findings after surgical treatment were also described. We collected data on visual acuity, corneal findings (ring infiltrate or radial keratoneuritis), presence of mydriasis, cataract, intraocular pressure, and indication for penetrating keratoplasty or filtering surgery.
Results: :
We were able to identify 13 patients with mydriasis, cataract, and glaucoma among 370 patients with AK. All patients were soft contact lens users, except one that was a rigid contact lens user. This signs appeared after a mean of 7 months after the beginning of the symptoms. The initial visual acuity ranged from 20/25 to hand motion and de visual acuity after the surgical treatment was 20/200 or worst. In only one case the final visual acuity was 20/30. The intraocular pressure average was 29.8 mmHg before surgery. Among these 13 patients, only one presented radial keratoneuritis, all others presented ring infiltrate. All patients underwent penetrating keratoplasty, extracapsular lens extraction, intraocular lens insertion in the bag, and iridoplasty. Seven of them also had filtering surgery to intraocular pressure control.
Conclusions: :
Acanhtamoeba keratitis is a sight-threatening disease and its early diagnosis is mandatory for a better prognosis. We described a new set of signs and symptoms related to AK and concluded that need of surgery was a risk factor for a poor disease prognosis.
Keywords: Acanthamoeba • contact lens • anterior segment