Differential precision of corneal Pentacam HR measurements in early and advanced keratoconus.

Background/aims: Serial Scheimpflug corneal tomography to monitor the progression of keratoconus has become standard practice in most countries where corneal cross-linking is available. The tomographic definitions of progression are, however, poorly defined. The aims of this study were: (a) to estimate the 95% limits of intraobserver and interobserver agreement of corneal shape parameters on Pentacam in patients with keratoconus and (b) to investigate whether these limits of agreement varied according to disease severity.

Allergy and contact lenses.

Allergic conjunctivitis is a response to environmental allergens, as well as a genetic predisposition of the patient. It is classified as either acute (seasonal allergic conjunctivitis) or chronic (perennial allergic conjunctivitis, vernal keratoconjunctivitis, atopic keratoconjunctivitis and giant papillary conjunctivitis). The immune mechanism of these diseases will be discussed, as well as the allergic response to contact lens wear.