Faculty Bibliography

PURPOSE: We present the management of a patient with large pterygia complicated by irregular astigmatism and corneal opacities. Visual rehabilitation required both surgical excision and contact lens fitting. METHODS: We examined a 30-year-old man with hand motion vision from a large pterygium overgrowing his right cornea. Histopathology was consistent with pterygium. During the first few postoperative weeks, his uncorrected visual acuity improved to 20/60, and manifest refraction yielded no further improvement. In the subsequent months, there were increasing anterior stromal corneal opacities, and the refraction became hyperopic to a variable degree. RESULTS: Best corrected visual acuity was 20/70-20/100. Axial length was 22.64 +/- 0.07 mm. Computerized corneal topography 6 months postoperative was similar to the preoperative topography and revealed irregular and asymmetric astigmatism, with marked variation of the central corneal dioptric power. Slit lamp biomicroscopy suggested that the corneal opacities were responsible for the patient's decreased acuity; however, contact lens fitting provided 20/30 vision with a rigid gas permeable contact lens. CONCLUSIONS: The improved vision with contact lens therapy strongly suggested that the irregular and asymmetric astigmatism were more visually significant than the corneal opacities

BACKGROUND: Herpes simplex keratitis is the most common misdiagnosis in patients with Acanthamoeba keratitis, which is increasing in frequency and is associated with daily wear soft contact lenses. Both entities usually present as unilateral keratitis. The manifestations of superficial Acanthamoeba keratitis (i.e., unilaterality, dendriform appearance, positive response to antivirals, and decreased corneal sensation) increase the opportunity for misdiagnosis as herpes simplex keratitis. The authors have encountered six patients with Acanthamoeba keratitis in whom the correct diagnosis was delayed from 2 weeks to 3 months. METHODS: All six patients underwent testing with the Cochet-Bonnet esthesiometer and extensive pharmacologic treatment for herpes simplex keratitis. Corneal scrapings were taken between 2 and 6 weeks after the initial examination. RESULTS: In all six patients, corneal sensation was decreased significantly. Drug therapy was ineffective. Cultures were positive for Acanthamoeba. Five of six patients underwent penetrating keratoplasty. CONCLUSIONS: Decreased corneal sensation has contributed to the misdiagnosis of Acanthamoeba as herpes simplex keratitis. Misdiagnosis results in delayed treatment and worse outcome. The authors found that significantly decreased corneal sensation is a frequent finding in early Acanthamoeba keratitis. Therefore, physicians should consider Acanthamoeba keratitis as an alternative diagnosis in patients with presumed herpes simplex keratitis with decreased corneal sensation