Abstract
Purpose: :
This study aimed to describe the prevalence of topographic keratoconus diagnosed de novo in the elderly in asymptomatic patients.
Methods: :
All consecutive patients who underwent cataract surgery performed by the same surgeon in the last thirty-three months were selected. Corneal topography were performed in all the patients in the preoperative examination. Rabinowitz criteria were selected to make the diagnosis of topographic keratoconus. Slit lamp examination was performed to detect clinical signs of keratoconus. Previous diagnosis of keratoconus and any corneal abnormality were exclusion criteria to be involved. Elevation topography with Orbscan II TM was performed in patients affected or with suspicious keratoconus to confirm diagnosis.
Results: :
A total of 1012 patients were included between January 2006 and September 2008. The mean age was 74,24 years (95% CI: 73,55-74,94). Sixty-nine patients (6,8%) with a central K reading more than 47.2 D were found. The mean age of this subgroup was 74,69 years (95% CI: 72,06-77,32). Four keratoconus were detected according Rabinowitz criteria and were confirmed by the topographic pattern in Orbscan, what implies a prevalence of 0,39% (95% CI: 0,13-1). No clinical signs were found in any cornea as opposed to the typical presentation in young symptomatic patients.
Conclusions: :
Topographic keratoconus presenting for the first time in the elderly in asymptomatic patients is not uncommon. Prevalence is higher than reported incidence of clinical keratoconus of 0.05% in the general population.
Keywords: keratoconus • cataract • aging